Timstar Brochure | April 2024

This is for you! Take a look inside and see what you think!

Are you looking for practical support?

Read more inside...

Delivery charges

FREE delivery on all orders* of £75 and over. Orders of less than £75 are subject to a £7.50 delivery charge (within UK mainland).

We aim to dispatch all stocked items ordered before 11am, on the same day.

* Delivery to Scottish Highlands and Islands is subject to a surcharge. Please contact customer support for an estimate.

Carriage Surcharges

Some of our Highlights...

Inspiration for you, inspired by you

We’re passionate about supporting science educators to engage and empower the students they teach. We’re inspired by the valuable work you do every day, and our spring brochure is a resource through which we can help support you with ideas, insights, and inspiration. In this issue, you’ll find details of our new and extended ranges, as well as useful functionality on our website – such as Shop by Practical. Some of our most popular categories have been enhanced to include the products you need most – we have something to suit almost every activity you’ll deliver.

Certain chemicals e.g., lithium, potassium, methanol, bromine etc, may now only be transported by ADR vocationally trained drivers. As such, we have implemented a carriage surcharge of £12.50 if an order contains these chemicals.

All chemicals with the surcharge are clearly highlighted online. Any over-sized or weighted items may be subject to specific delivery charges. For help and advice email us at customer.support@wf-education.com

The important bit…

T&C’s: All prices shown in this brochure are ex. VAT.

Need advice?

Please, call our friendly customer support team (Mon - Fri, 8.30am - 5pm, excl. Bank Holidays) on 01743 812 200 for advice on your delivery options, prices, and product selection. We offer additional delivery options including guaranteed next day.

We also have an experienced technical team to answer all your questions regarding our products, troubleshooting, or any health and safety queries.

time of print.

For full and most up-to-date terms and conditions, please, visit wf-education.com/terms-and-conditions

NEW FOR 2024!

We’ll work with you to create an inspirational new science laboratory. Our specialist design team will consult with you and your colleagues to make layout suggestions that will maximise your space and budget.

We have taken care that the elements we offer are robust and appropriate for school use and place importance on providing quality furniture and equipment that will stand the test of time. We are an expert ISO 9001 accredited team, drawing expertise from our in-house space designers, layout and

Scan here to find out more...

space planners, and education sector health and safety specialists as well as consulting regularly with teachers and technicians.

A Timstar lab provides space for a mixture of practical and non-practical activities and includes consideration of demonstrations, presentations and discussion, individual, small group, and class work, experimentation, and research.

Our new ranges are designed to inspire ideas of how to enhance practical science and provide plentiful opportunities for hands-on learning.

NEW! We are delighted to expand our range to include the fantastic education-ready BMS Microscopes. Book your FREE demo with your local rep..

NEW! We’re now stocking a great new selection of British-sourced dissection samples and dissection tools to support practical activities!

NEW! Shop all you need to support GCSE and A Level required practicals on our website. Including all equipment and consumables, we’re a one stop shop to get stocked up.

Design it, fit it, fill it – with Timstar! Work with our friendly team to design your next amazing laboratory or prep room space.

Enriching Biology, Supporting Outcomes

We’ve been busy! If you are looking for a one-stop biology shop, look no further than Timstar.

During 2023 we explored the biology curriculum for AQA, Edexel, OCR and WJEC at GCSE and A Level (Scotland will follow, as will IB). Our comprehensive range supplies all the products you will require.

So, if you want biology, look no further!

View the whole range on our website!

Looking for drosophila? Now available from Timstar.

Drosophila melanogaster, fruit flies, are often found near overripe and rotting fruit and are an ideal species for behaviour and genetics studies.  Find out more on pages 16 and 17.

For information on our new online required practical lists see pages 20 – 21.

We are pleased to announce a new partnership with BMS Microscopes.

W arranty 5 YEAR

A well established, high-quality brand offering a structured range of microscopes and cameras for the education market.

See pages 6 – 9 for further detail.

NEW!

NEW!

We have reviewed our genetics and biotechnology products.

We have been partnered with Edvotek®, the world’s leading supplier of safe, affordable and easy-to-use biotechnology kits and equipment designed specifically for education, for many years. We continue to add their new products and kits, keep checking online for new additions.

For more information, please see pages 30 - 31 or view the entire range online!

We are pleased to offer a full range of dissection specimens.

Frozen or preserved options, sourced from British abattoirs with the highest standards of animal welfare.

See pages 22 - 23 for how to download our kidney dissection worksheet!

NEW! Stereo microscope

The latest model

NEW! Advanced model

Bestselling model

Timstar is incredibly pleased to launch the full range of high-quality microscopes and cameras from BMS Microscopes

What do you get when you buy a BMS microscope?

To learn more about objectives and the difference between achromatic, Semi-Plan, E-Plan and Plan, High-quality microscopes developed with schools in mind

Free demonstrations from our sales team

Ongoing technical support

5-year warranty

Competitively priced

NEW!

BMS 100 FL LED Microscope

Our most popular microscope. Combining fantastic optics, strong body and stand, and all parts locked to the microscope. What’s not to love?

MI240020

NEW!

BMS 200 FL LED Microscope

Looking for an affordable microscope to use with your camera? The BMS 200 FL LED is the perfect choice!

MI240030

The total magnification of a microscope is the multiplication of the eyepiece magnification and the objective magnification.

£127.50

£160.00

BMS

037 LED Microscope

TWO microscope types in ONE – an incident and transmitted light microscope. Easy to transport, quality optics and great value.

MI240010

BMS D2 Microscopes, 1000X

Developed for use in education and professional laboratories, this high-specification microscope offers ergonomic design, sturdy components and high-quality LED. Featuring sPlan objectives, integrated X-Y specimen holder and an Abbe condenser which can be exchanged for darkfield or phase contrast condensers.

MI240110 Monocular

MI240120 Binocular

MI240130 Trinocular

Want to see the full specification?

BMS 146 FLArQ Microscopes

These BMS FLArQ microscopes are ergonomically designed with a reverse nosepiece for ease of access to the slide. They feature total magnifications of x40, x100 and x400, a rack and pinion system for the condenser and an integrated mechanical stage.

MI240050 Monocular

MI240060 Binocular

MI240070 Trinocular

BMS D3 Microscopes

A new approach for higher demands in microscopy. In a nutshell: flexible, efficient, stable and comfortable in use. Offering quintuple nosepiece with ePlan objectives, large working stage which will hold 2 microscope slides and magnification of up to 1000x.

MI240220 Binocular

Trinocular

BMS EDULED FLArQ Microscopes

A high-quality, well-equipped microscope with Semi Plan objectives and a height adjustable Abbe condenser with iris diaphragm, making it suitable for the addition of a 100x oil immersion objective. Coarse and fine coaxial focussing and a mechanical stage combined with an ergonomic design and built in carry handle make this the ideal microscope for advanced microscopy.

MI240080 Monocular

MI240090 Binocular

MI240100 Trinocular

BMS S-40-2L LED Stereo Microscope

A stereo-microscope, also known as dissecting microscope. This model offers magnification options of 20x and 40x.

MI240140

£210.00

£305.00

£350.00

£370.00

£475.00

£545.00

£175.00

£725.00 MI240230

£825.00

£99.00

£285.00

£380.00

£425.00

The digital classroom! Biology lessons can be made more engaging for students with the addition of digital microscopy.

The range of BMS cameras offers options including USB, Wi-Fi, HDMI and a selection of different resolutions, to suit all budgets. Images can be viewed on tablets attached to the microscope or projected onto laptops or screens, creating an immersive lesson enhancing student’s understanding.

Some features of the easy-to-use software allow you to:

Conduct measurements in microns, millimetres, centimetres, inches, feet, etc. under any magnification power and within desired tolerances.

Adjust colour balance, exposure, saturation, contrast and orientation. Conduct measurements for single, parallel or perpendicular lines and rectangular, elliptical and irregular areas.

Add notes, measurements, text, arrows, labels.

USB Cameras

A USB microscope camera connects to your microscope on a c-mount adapter or over the microscope eyepiece and plugs directly into your computer or laptop with a USB connection.

MI240150 USB 2.0, 3.1MP

MI240160 USB 2.0, 5MP

WiFi Cameras

WiFi microscope cameras connect to your microscope and create their own WiFi signal.

MI240170 WIFI 2.5MP

MI240180 WIFI, 1.0MP

£175.00

£199.00

£420.00

£215.00

An introduction to measuring with microscopes and cameras.

Microscope calibration is a required practical for all exam boards at A level and is found in the “cells” topics.

The eyepiece graticule (or reticule)

Eyepiece graticule (arbitrary units)

Eyepiece graticule (reticule): arbitrary units

1

graticule unit

Microscope eyepiece

This is either fitted into the eyepiece or can be added separately. It is an arbitrary measurement, which when calibrated with a stage micrometer, can be used to indicate the size of the object being magnified.

BMS SyncCam 12MP

A 12 MP camera with built in microphone.

MI240190

£450.00

Working out cell sizes and magnifications is also present in the GCSE specifications.

Stage micrometer (calibrated scale)

stage micrometer: 1 mm in 0.01 mm divisions

Microscope slide

This is a measurement scale, in SI units, embedded into a microscope slide that has been factory calibrated to ISO standards. This means that you can be confident when using it to calibrate the graticule that your measurements will be accurate and reproducible.

Micrometers come in a range of sizes, although most common is the 1 mm micrometer, divided into 100 divisions of 1 μm (0.01 mm)

BMS Cellpad Mini, 7-INCH

Mounts onto the microscope head of the 037, 146, EduLed, D2 and D3 microscopes.

MI240200

Want to see the full specification?

£435.00

BMS Cellpad 3, WIFI, HDMI, 5MP

All in one C-mount camera (HDMI, WiFi, SD card) with high sensitivity and ultra high performance Sony CMOS sensor. HDMI and WiFi are used to transfer the data to either a HDMI display (screen) or to a computer.

MI240210

£900.00

Don’t get confused when buying histology slides for your department ever again!

There are many different terms used in slide section terminology. Longitudinal and transverse originate from human anatomy dissection and incorporate terms such as sagittal/ coronal planes of the body.

Most slides used in educational biology will be labelled as longitudinal or cross section.

With our handy guide opposite, you can familiarise yourself with all the types of slide sections available for your biology team, from CS to WM!

A transverse /cross/ horizontal section is cut across the width (perpendicular to the long axis) of the specimen

A longitudinal/vertical section is cut down the length (long axis) of the specimen

Some examples are shown here...

Created by Wilhelm His, a Swiss anatomist, the microtome is a mechanical apparatus widely employed in microbiology for slicing embedded tissue to generate exceedingly fine sections. A microtome is particularly useful because it can be used to produce and reproduce sections of uniform (and desired) thickness for microscopy

Cross section of an onion

Longitudinal section of a flower model

Whole mount of a honeybee leg

This table should help you to better understand what each slide will show.

Abbreviations used

Type of slide section

E Entire

WM Whole Mount

LS Longitudinal section (along the axis)

VS Vertical section

TS Transverse section (perpendicular to the longitudinal axis)

CS Cross section

HS Horizontal section

VLS Vertical longitudinal section

HLS Horizontal longitudinal section

To allow us to see detail in cells, we need the help of a microscope. For teachers and pupils to best view their slides, we would recommend a Trinocular Microscope. See page 7

A microscope camera is a useful tool when identifying cell level images and sharing them with the class.

Fantastic for sharing ‘live’ images from the mitosis required practical. See page 9

Prepared Microscope Slide Sets

For details of the contents of our slide sets please see our full range online.

Want to see the full range?

Search prepared slide

If your school or college is refurbishing or creating new science teaching or preparation spaces, this guide is for you!

“Your Laboratory Design Guide” has been written specifically for departmental staff, facilities management, and school leadership to support decision-making alongside architects and space planners and help to ensure that you have a facility that is fit-for-purpose for years to come.

Scan to download your FREE copy!

“School science laboratories are an expensive investment and are expected to last for many years. A poor design will impact on generations of pupils, teachers, and technicians.”

The Association for Science Education

We understand the importance of creating effective educational environments. While redesigning educational spaces may be infrequent for most, we’re here to support you every step of the way and make the most out of your laboratory spaces.

Customised Lab Design

Our labs are versatile, catering to a variety of activities, from demonstrations to research, fostering student engagement and learning. We prioritise creating attractive, engaging laboratory spaces that stimulate pupils’ learning, along with well-planned preparation areas for teaching and technical staff.

Insights include…

Considerations when designing a science space

Requirements for different types of lab

Storing hazardous materials

Comprehensive Service

The prep room

Fume cupboards

Technical information

Our service streamlines the process, from design approval to installation, providing coordination of all trades for a seamless experience. Additionally, we offer a unique chemical store service, advising on your chemical storage with expert care and compliance.

Our experienced team pays attention to every detail, from DfE requirements to acoustics, ensuring a comprehensive approach to your space.

Contact us today to embark on your customised lab journey with Timstar!

Don’t

just take our word for it!

Wendy Thorburn, Lead Science Technician, Kingdown School

“Timstar’s service was excellent, communication was very good between the project manager, me and our site team who worked on the lab refurbishment. We’re delighted!”

Using bacterial transformation scientists can produce antibiotic resistant bacteria as well as other things like producing insulin or allowing plants to become disease resistant.

Gene technology is studied in all the A Level Curricula:

OCR A: Manipulating genomes

AQA: Gene technologies

Edexcel A: Gene technology

How does it work?

The reason bacteria are such a good model for transformation comes from the way the bacterial cell is designed.

The chromosomal (nucleoid) DNA is not bound within a membrane as it is in eukaryotic cells, and bacterial cells also contain plasmids, circular pieces of double stranded DNA containing extra (non-essential) genes. It is these plasmids that are the key to transformation.

Search DNA

Want to find

out more?

Edexcel B: Microbiology and pathogens

WJEC: Variation/ inheritance

Visit our Resource Hub for lots more information about transforming DNA. Search ‘DNA’.

The antibiotic ampicillin works to prevent bacteria from growing by interfering with cell wall synthesis.

A gene for ampicillin resistance (β-lactamase) is carried on a plasmid.

If this gene (or the plasmid) is added to a second bacteria, it will start to secrete β-lactamase, and will become resistant to ampicillin, meaning that it will continue to grow in the presence of this antibiotic. Furthermore, it will continue to reproduce, exhibiting this gene.

Bacteria have the ability to do this naturally, but we can also do this in the laboratory (under specific conditions). This means that scientists have been able to make bacteria producing insulin, and disease resistance in some plant varieties. This is a method of genetic engineering.

In order to support the students learning of this important topic, we supply 3 bacterial transformation kits from Edvotek®

Transformation of E. Coli with Green Fluorescent Protein (GFP) Kit

In this experiment, students will explore the biological process of bacterial transformation using E. coli and plasmid DNA. At the end of the activity, students will have experience observing and analysing acquired traits (ampicillin resistance and fluorescence) as exhibited by transformed bacterial cells.

• Explore genetic engineering with this elegant experiment

• Transform E.coli with pFluoroGreen™ - a plasmid containing genes for ampicillin resistance and the green fluorescent protein

• Select for transformed cells using LB-ampicillin plates and calculate transformation efficiency

• Expose transformed cells to IPTG to demonstrate differential gene expression

• New transformation protocol has high transformation efficiency = great results!

BI130985 £84.60

Transformation of E. Coli with Blue & Green Fluorescent Proteins

In this experiment, students will explore the biological process of bacterial transformation using E. coli and plasmid DNA. At the end of the activity, students will have experience observing and analysing acquired traits (ampicillin resistance and fluorescence) as exhibited by transformed bacterial cells.

• Explore genetic engineering in this elegant and expanded experiment

• Transform E.coli with either pFluoroGreen™ or pFluoroBlue™

• Select for transformed cells using LB-ampicillin plates and calculate transformation efficiency

• Expose transformed cells to IPTG to demonstrate differential gene expression

• Different plasmids help emphasise the concept of DNA>RNA>Protein>Trait

BT97940

Rainbow Transformation

£99.95

In this colourful experiment, students will explore the biological process of bacterial transformation using vibrant chromogenic proteins. Students will use three recombinant plasmids to transform E.coli bacteria. The resulting E.coli will be examined for the presence of blue, purple, and pink pigments, as well as for resistance to ampicillin. Features new enhanced transformation protocol for improved student results.

• Explore genetic engineering with this colourful experiment

• Transform E.coli with plasmids that contain a gene for ampicillin resistance and a gene for either a blue, purple, or pink pigment

• Select for transformed cells using LB-ampicillin plates and calculate transformation efficiency

• Expose transformed cells to IPTG to demonstrate differential gene expression

• Different plasmids help emphasize the concept of DNA>RNA>Protein>Trait

BT150274

Want

to explore all of our Edvotek® Kits?

Search ‘Edvotek’

£110.65

Drosophila are also known as fruit flies and are often seen hovering around decomposing fruit.

Drosophila is mentioned in the A level specification, in the inheritance section of genetics.

AQA: Topic 3.1 inheritance: Investigate genetic ratios using Drosophila

OCR A: PAG 12.2 Research skills: genetic crosses in fruit flies

OCR B: Topic 5.11: Patterns of inheritance

Edexcel B: Topic 8: Origins of genetic variation

WJEC biology: Topic 5: Variation and inheritance (although Drosophila is not specifically mentioned here)

Drosophila (and more specifically Drosophila melanogaster) have been used as agents to study genes and inheritance since 1910 when Thomas Hunt Morgan identified the white gene.

Although even before this, in 1901, the entomologist Charles Woodward was the first to successfully breed Drosophila and proposed its use as a model organism for study.

They are now used worldwide, and their genetics have been extensively studied making them one of the leading genetic models in the world today.

Drosophila have only 4 pairs of chromosomes making up their DNA, with approximately 14,000 genes, significantly less than that of humans (estimated to be 20-25,000). Having so few chromosomes makes studying the genetics of fruit flies very easy, and they have lots in common with humans, because of a shared evolutionary path: brain and nerves/digestion and circulation, and body organisation all have similarities to our own (and that of other animals).  Drosophila have a short life span and females produce a lot of offspring, making them an efficient and cost-effective way of studying ‘live’ genetics.

Genetic mutations in the fruit fly have some easy to visualise phenotypes (the outward appearance of the genetics): the red/white eye; short (vestigial) wing/normal wing; ebony body/normal body. You can also get more than one genetic mutation on a single fly: (ebony body/vestigial wing for example, and there are many more phenotypic variations.

One of the great things about using Drosophila to study genetics is the ability to easily manipulate them, they can be anaesthetised very easily and revived with no ill effects, and you can breed wild type and mutant, or mutant and mutant, and study the offspring, all over a period of a just few weeks.

Handling, storage and care of Drosophila

You will receive your Drosophila direct from our supplier in a taped vial.

As soon as you receive them, remove the tape, but not the foam insert, this will allow airflow into the vial.  In the vials the flies will use the media for nutrition, you will need to move them onto fresh media every 10-20 days, to allow them to thrive.

For a full guide about how to move flies between vials and how to safely use Fly Snooze, please visit our Resource Hub and search ‘Drosophila’.

Drosophila

Cultures and segregated flies are supplied in glass specimen tubes. All Drosophila are bred, and sexed, in-house at our supplier.

All flies are dispatched on Mondays - please advise when ordering your preferred delivery week.

BP230150 Wild type culture

BP230160 White eye culture

BP230170 Vestigial (short) wing culture

BP230180 Ebony body culture

BP230190 Scarlet eye culture

BP230200 Ebony vestigial culture

BP230210 Wild type males

BP230220 White eye virgin females

Ready-Made Drosophila Tubes with Media

High quality fruit fly food with an anti-mould agent in 10 cm glass specimen tubes. Extra delivery charge will apply. BP230230 £21.20

Want to find out more?

Search ‘Drosophila’

Fly Snooze Kit

For anaesthetising Drosophila. Flies remain immobilised for at least 50 minutes. Kit contains 10 mL vial of Fly Snooze and 12 anaesthetic wands. separate anaesthetiser is not needed. Easy to use and safer than ether. Kit contains 100 doses. BL90415 £36.50

£14.10

£14.10

£14.10

£14.10

£14.10

£14.10

£37.50

£53.40

Bacteria will arrive in your department as an inoculated slope (or slant). The agar has been poured into the bottle on a slope and bacteria is added to this. The reason for the slant is to give a large amount of agar for the bacteria to grow on, but it also makes it easy to remove what you need for experiments.

After preparing your nutrient agar petri dishes, you need to remove some of the stock bacteria:

Working aseptically, touch and gently drag an inoculating loop through the bacteria on the slope.

You don’t need to dig into the agar, there should be plenty of bacteria on the surface.

You then need to add this bacteria to a plate in order to grow it on further for experiments.

Bacteria

should be sub-cultured onto sterile nutrient agar/broth within 1 week of receipt and every 2 weeks thereafter.

Incubate at around 25°C until growth is visible (around 2-3 days) then store in the fridge (4°C). Bring up to room temperature before using.

We have more information about bacterial colonies, sterilization and autoclaving as well as agar. Scan to explore microbiology in the Resource Hub!

You can practice streaking a plate using glycerin with food colour mixed in, on a jelly (rather than agar) plate, or make the plate with technical, not nutrient, agar.

Streaking a plate

The aim of streaking a plate is to spread the bacteria until you can see single colonies on the plate. The initial ‘blob’ of bacteria on the loop will contain thousands of bacterial colonies, this needs to be spread as thin as possible. Streaking is the tried and tested method of doing this.

1. Drag the loop across the plate whilst also moving down towards the middle (but stop at about ¼ the way down)

Wire inoculating loop (in loop holder)

2. Turn the plate 1/3 turn and, using the loop draw several lines away from the initial streak

3. Turn the plate 1/3 way round and repeat step 2, but this time draw out the last line, back and forth and down across the remainder of the plate 1 2 3

Bacteria Cultures

Culture is supplied on a nutrient agar slope in a glass screw top universal bottle. Store in a fridge (2-8°C), bring to room temperature prior to use.

Culture at around 25°C.

BL80894 Bacillus megaterium

BL80900 Bacillus subtilis

BL80910 E.coli K12 Strain

BL80917 Micrococcus luteus

BL80920 Pseudomonas fluorescens

BL80930 Staphylococcus epidermidis

BL80954 Mucor hiemalis +ve strain

BL80960 Penicillium roqueforti

BL80980 Saccaromyces cerevisiae

Petri Dishes, Polystyrene, Sterile

Disposable, triple vented petri dishes.

PE12035 90 mm, pack 20

PE240000 90 mm, pack 480

PE12030 55 mm, pack 20

PE12031 55 mm, pack 600

A needle holder suitable for innoculating loops. Nichrome wire is suitable for

DI05920 Single needle holder

DI05921 Pack 10 needle holders

DI05925 Pack 10 nichrome wire loops

Bacterial Spreader

Stainless steel rod bent to facilitate spreading bacterial dispersions evenly over an agar plate.

DI230130

Petri Dishes, Simax

Petri dishes made from heat resistant soda glass. Supplied in a pack of 10.

PE230000 60 x 12 mm

PE230010 80 x 15 mm

PE230020 90 x 15 mm

PE230030 100 x 15 mm

PE230040 120 x 20 mm

£18.40

£18.40

£18.40

£18.40

£18.40

£18.40

£18.40

£18.40

£18.40

£2.05

£19.90

£3.90

£17.50

£2.60

£56.20

£2.10

£64.95

£11.30

£12.70

£13.90

£15.30

£22.20

Required practicals

Busily working behind the scenes, we have looked at all the A level and GCSE curricula* for biology and all the required practicals/core practicals/PAGS.

We carefully evaluated each practical, looking at them from the technician’s point of view – this meant not only checking the equipment that the student will need, but also including any extra equipment techs will need to set up the practicals for the prectical session (thinking incubators, autoclaves etc.).

So, if you are looking for ‘Shop by practical’, look no further!

View on our website!

NEW FOR 2024!

Our aim has been to give you a comprehensive list of equipment needed for EVERY required practical in biology for A level and GCSE. Alongside this list of equipment, we have added any tips that will help and any content that we have written around these subject areas to enhance your understanding of the science behind some of these experiments.

We really hope that you will find the required practical/shop by practical resource immensely helpful in your work as a technician – you can use it to order equipment you will need for the practical, ensure that you have covered off all the equipment on the list and even identify some equipment on the list that you don’t yet know (what even IS a Thiele tube?!).

We have organised our navigation by GSCE or A Level and sorted by exam board and then by practical!

Please note we have launched our required practicals with biology, we are working on physics and chemistry. We’ll keep you posted!

Curricula covered GCSE

AQA

Edexcel

OCR gateway and 21 century

Curricula covered A level

AQA

Edexcel A and B

OCR A and B WJEC WJEC

*(with the exception of Scotland and IB – more to come later)

For each practical we have included the abstract, some of our top tips and everything you need for the required practical with some alternatives too

Dissection of a mammalian kidney

Kidney dissection is a useful tool to help understand how the organ functions in relation to filtering waste products from the blood and the formation of urine and it is often carried out as a teacher demonstration at GCSE level.

Kidney dissection features in the WJEC A level specification (practical 26 in the homeostasis and the kidney topic) and it is expected that the students will do the dissection themselves, with some guidance. Other specifications focus on heart dissection.

Humans, like all mammals, have two kidneys.

Shaped like a kidney bean, and about the size of your fist, they are sited either side of the spine just below the rib cage.

The main function of the kidney is as a filter, removing toxic waste products from the blood, but it also regulates the solute concentration of the blood (osmoregulation).

The kidney contains millions of nephrons to carry out this process of filtration and osmoregulation, all with a good blood supply. The students will learn about ultra filtration and selective reabsorption along the loop of Henle, inside each nephron.

Other functions of the kidney include hormone production (renin is produced which helps blood pressure regulation), acid-base regulation, and, along with the liver, glucose regulation.

Kidney stones are hard mineral deposits that accumulate within the kidney, and sometimes can block the ureter (exit tube) of the kidney causing pain, inflammation, and infection. This is due to a high concentration of salts/minerals and waste products in the blood compared to the volume of water.

We have a great worksheet about heart dissection. Free to

Observing the cellular structure of the kidney

To further investigate the cellular structure of the kidney, remove a very small (smaller than your little fingernail) piece of tissue and place it on a microscope slide with a drop of water.

Place a coverslip over the top of the sample and a piece of tissue or paper towel on top of this. Then press down hard with your thumb. This will spread the tissue out into a very thin layer

Human Kidney Model, 3 Sections

Looking under the x4 and then the x10 objective you should be able to identify cells from the kidney. This will be better with smaller and well squashed tissue samples.

You should have some proprietary slides of kidney tissue to aid identification. Timstar supply prepared slides: VS, code PM86765 and LS, code PM86770.

Human kidney model includes 3 parts - kidney section, 3 times life size, nephrons and blood vessels 120 times life size, and kidney glomerulus opened, 700 times life size.

Frozen Lamb’s Kidneys, Pack 5

Kidney with Adrenal Gland Model, 2 Parts

This model shows the kidney with an adrenal gland as well as renal and adrenal vessels and the upper portion of the ureter. Removable front half of the kidney to show cortex medulla and vessels as well as renal pelvis.

Follow this link to view the full range of dissection equipment and specimens

MO230020 £75.00

MO130525 £36.95

Whole lamb’s kidney with vessels attached, suitable for student dissection.

BP230130 £21.35

A level required practical: Effect of a variable on the permeability of membranes

Practical specification links

AQA: Effect of changing ethanol concentration on beetroot cell membranes

OCR A; EDEXCEL A & B; WJEC: Effect of changing temperature on beetroot cell membranes

Tips for preparing the beetroot

For this practical, cylinders of raw beetroot are required, all of the same size. Often these are pre-prepared by the technician, and a cork borer is used. This is a laborious, sometimes painful task and wastes a lot of beetroot. Using a potato chipper is an excellent way of producing many rectangular (chips) of equal size, with minimum wastage.

After cutting the beetroot, the ends should be removed (making sure the ‘chips’ are consistent in length), they should then be placed in a beaker of distilled water to allow for any betalain leakage (due to the physical membrane damage caused by cutting the beetroot) to be removed from the system before the students do the practical. They can be stored in the fridge overnight and placed in fresh water when the students are ready.

Using a colorimeter in this required practical

When using the colorimeter, the students will require a blue/green filter (530 nm).

The AQA practical requires a stock solution of betalain: adding beetroot discs into a solution of 100% alcohol (ethanol or methanol can be used). This extract, when mixed with water, can also be used to make colour standards for the colorimeter. (see the practical specification for more details).  Edexcel use % transmission rather than absorbance to measure betalain concentration. % transmission is the opposite of absorbance (so 0 absorbance = 100% transmission and the solution will be clear).

Ultrospec 35c Colorimeter

The Ultrospec™ 35c Colorimeter measures the absorbance/transmission of liquid samples in either a cuvette or test tube at fixed wavelengths to determine molecular concentration. See online for the full technical specification.

CO240000 £1,410.00

Phywe Cobra SMARTsense Colorimeter Sensor

This Phywe colorimeter sensor is ideal for measuring the transmittance or absorbance of samples at different wavelengths. In addition, turbidity can also be determined.

Mystrica Colorimeter

The Mystrica colorimeter delivers high quality performance in a small, robust, user-friendly and affordable package.

CO100720

Each £126.00

CO160740 Pack of 4 in a tray

£467.50

DA220370 £352.85

Enzymes feature heavily in the biology curriculum at both GCSE and A level.

Enzymes can be particularly temperamental, and it is always worth testing them before any practical. Enzyme troubleshooting:

Check the optimum working conditions of the enzyme for pH and temperature. See our Resource Hub for a table on enzymes with more details of working conditions.

Do not make the enzyme up in hot (greater than working temperature) water, use distilled water and check the pH.

Make sure that both the substrate and enzyme have had time to come up to room temperature if they have been stored in the fridge.

Ensure that the enzyme and substrate are well mixed and don’t add an enzyme to a hot substrate, this applies especially to starch which is best made using boiling water. Allow the starch to cool to room temperature before adding any enzyme. (Heat will denature the enzyme and render it useless).

Decrease the concentration of the substrate (so the ratio of enzyme to substrate is higher).

Increase the concentration of enzyme (so the

Follow the same protocol as the students will use to test the enzyme. If they will be looking at the action of amylase on starch at different temperatures, using spotting tiles, do the same. The activity of the enzyme in a large volume of starch in a test tube will not show up as the volume of starch is so large compared to the volume of amylase, however, it will show in the spotting tile.

Beware of contamination of starch stock solution with the enzyme. Although (as noted above) a drop of amylase in a test tube of starch may not show digestion initially, left overnight even a single drop of amylase will work its way through a beaker of starch which means the practical will not work the next day. So, make sure the pipettes you are using do not get muddled and end up in the wrong beakers.

Storage: ensure you are following the correct storage procedures for each enzyme. Storing enzymes too cold can be just as damaging to them as storing them too hot.

Enzymes Set

A set of eight tubes of 10 g each of Amylase (Diastase): bacterial and fungal, Invertase, Lipase, Pancreatin, Trypsin and Urease. Complete with teaching notes.

Enzymes have specific temperatures and pHs that they work best at. We have a table showing this for all products in our range. Search ‘Properties of Enzymes’ on the Resource Hub to find out more!

How do enzymes work?

Enzymes are highly specific for the reactant (substrate) they are reacting with. Enzymes are made of protein. Proteins are made of strings of amino acids that are then folded in a specific way (depending on the protein); thus, the enzyme will be folded in a specific way that will fit the substrate perfectly. Where the substrate binds to the enzyme is called the active site (of the enzyme) and this is different for every enzyme-substrate pairing. The specificity of this interaction led to the “lock and key” hypothesis of enzyme action: the lock being the enzyme that the substrate ‘key’ fits into, every lock being specific for its complimentary key.

Green algae, such as Scenedesmus quadricauda have become excellent teaching resources especially when studying photosynthesis.

Although algae aren’t plants, they are eukaryotic (usually aquatic) organisms that produce nutrients by photosynthesis.

The beauty of using algae in the classroom is that it is small and fast growing, you can buy it quite cheaply and then ‘bulk it up’ for long term use in experiments, and it photosynthesizes really fast, so experiments can be completed well within (most) lesson times. Algal photosynthesis is generally more efficient than plant photosynthesis, as they use more light absorbing pigments and carbon dioxide concentrating systems to get the most out of the CO2 and light available to them.

Chlorophyte algae: Scenedesmus quadricauda

We have more information about algal balls and how to set up and perform this experiment. Visit our Resource Hub and search ‘Algal Balls’.

Scenedesmus Quadricauda 30 mL Tube

Scenedesmus quadricauda is a green freshwater algae, typically 4 cells with a spine at each corner. It is quick and easy to grow, and ideal for use in many experiments including in the algal ball experiment for studying photosynthesis.

BL180550 £16.40

7 mL Vials, Pack 190

Neutral glass with polythene clip-on cap.

VI16980

£48.50

Required practical - The core practical 6 in the Edexcel GCSE specification, asks students to look at the effect of light intensity on the rate of photosynthesis using algal balls.

If the algae look pale, they may need more light before the practical

If the practical is happening too slowly, add more algal balls to the tubes or decrease the amount of indicator

For good algae they should be bulked up, so the solution is a pea green colour, and exposed to light before use

Students place a prepared algal sample at several specified distances away from a bright light source and leave for a minimum of 60 minutes. A final prepared sample is wrapped in black paper or foil to block light and is placed alongside the sample nearest the light. This is a negative control.

Directly in front of the light source, a large beaker of water is placed, this acts as a ‘heat sink’ preventing the heat from the lamp reaching the samples and so removing temperature as a variable factor in the practical.

The result of this practical shows that the nearer the samples are to the light source, the more purple they are, meaning that more carbon dioxide is being used in photosynthesis. The dark control sample should look yellow as there is more carbon dioxide in the system than at the start, indicating that carbon dioxide is not being used up. (it is being produced from respiration of the algae).

Scan to watch a video of how to prepare and set up this experiment!

Biotechnology covers a whole range of processes important for identification, whether that is of a crime suspect, or parental (genetic) responsibility (DNA fingerprinting); or disease identification through mutation detection; or further understanding of heredity via sequencing.

Working with Edvotek®, Timstar can guide you through the process and share our recommendations of which kits are the most useful for each stage. We also have experts on hand to offer guidance and support.

The process...

1.

Extract DNA (from blood*/ saliva/hair)

2.

Amplify DNA target sequence (PCR)

1. DNA extraction: Kits to use

Extracting Fruit and Vegetable DNA

• Learn about the basics of cells and DNA

• Extract DNA from household fruits and vegetables

• Spool DNA to visualise genetic material

• Includes extraction buffer, test tubes, pipettes, and spooling stick

BT230060 £49.65

3.

Separate amplified fragments (electrophoresis)

4.

View and analyse fragments

*DNA is extracted from white blood cells in a whole blood sample.

Genes in a Tube Kit

Students perform a DNA extraction from their own cheek cells, via a simple cheek swab, and then store the extracted DNA in a “genes in a tube™” necklace.

This would be the first step in isolating DNA from a crime scene, as DNA can be isolated from the smallest sample of cells. BT97805 £110.00

To be able to study or visualise the gene or region of interest in the DNA we need to make a lot more of it, to do this PCR is needed.

2. Amplify target sequence: PCR

To make multiple copies of the target DNA sequence, the DNA is separated: step 1 denaturation. Next, primers (short complementary sequences of single stranded DNA that match the ends of the target sequence) are added, along with a polymerase enzyme which can add free nucleotides, dNTPs, to the end of the primers, to match the target sequence: steps 2 and 3 anneal and extend. At the end of this, new copies of the target sequence will have been made. The process (steps 2 & 3) is repeated 35-40 times (cycles), with extension giving millions and millions of copies of your target sequence.

Quick PCR Kit

Students are able to amplify preprepared DNA, followed by gel analysis (electrophoresis) BI130975

3. Separate amplified fragments (electrophoresis)

What Is PCR and How Does It Work? Kit

Pre amplified samples of DNA sequence, with the PCR stopped at different cycle numbers, to show the relationship between number of PCR cycles and amount of DNA. BT97925

After amplification in a thermal cycler (PCR machine), there will be a mix of different length sequences in the tube. To visualise these, they first need to be separated, and this is achieved through electrophoresis: a gel separation technique using an agarose gel and electricity. Fragments are separated based on size and thus their ability to move through the gel.

4. View and analyse fragments

After allowing the samples to separate on the gel, you need some way of visualising them (since DNA is colourless). This will depend on what you have added to the sample, either in the gel itself or as an external stain after running the gel. By adding a dye marker to the product, you can track the sample as it travels through the gel. The type of marker added will affect the type of visualisation system you will need: either UV or blue light, or a white light system.

All the kits supplied by Edvotek® for Timstar come with detailed instructions and background information. A second supportive resource: “Edvotek®: struggling with biotechnology?” is also available to download from our website.

If you are interested in our recommendations for kits to teach the various stages of the process, as well as comprehensive information and ideas about DNA fingerprinting, disease mutations, and Amanda’s top product suggestions for all aspects of biotechnology, please read our Resource Hub post here.

pH stands for ‘Potential of Hydrogen’: it is a measure of the concentration of hydrogen ions in a solution.

The pH scale is logarithmic – each whole number pH increase actually represents a tenfold difference in the acidity or alkalinity. This means that pH 2 is ten times more acidic than pH 3. So even though the difference of 1 pH may sound small it is actually quite sizeable.

Lemons are one of the most acidic fruits with a pH of 2. That is a reason why they are often used as cleaning aids. They also have a high vitamin C content. Their zest is used for baking and their leaves can be used in tea.

pH buffers are used in many solutions, to maintain them at the correct pH over time. The practical: the Hill reaction (decolourisation of DCPIP by chloroplasts) requires buffered solutions to be made.

Blood has a pH of around 7.4. This is controlled by respiration. CO2 dissociates into carbonic acid in the tissues. So, more CO2 means more acidic blood. Don’t hold your breath for too long as your blood pH will lower, and you might faint!

6.

Different plants grow better in different levels of soil pH. It is always helpful to understand the pH of your garden’s soil and choose plants accordingly to this. Hydrangeas, for example will grow in most soil pHs. However, grow them in acidic soil and you will get blue flowers, alkaline soil will produce pink flowers. A neutral soil (pH7) will give both pink and blue flowers on the same bush!

7. 8. 9.

Stomach pH is around 2. The addition of acid helps stomach enzymes break down proteins. To protect the stomach lining from these harshly acidic conditions, the stomach is lined with mucus.

The pH of saliva is between 6.5 and 7.5. Saliva helps to neutralise acids produced by bacteria which helps reduce the risk of tooth decay.

10.

The pH of the body is between 7.35 and 7.45. The renal system regulates the pH of extracellular fluid. If the acidity of fluids gets too high, the kidneys secrete H+ ions whereas if the alkalinity rises it retains H+ ions and secretes HCO3. Renal regulation is slow but effective. It is limited by the fact that the pH of urine cannot be below 4.4.

Some solids will only enter solution if they are at the correct pH: EDTA will only go into solution at pH8 – very handy when you need to make some EDTA in a hurry!

Timstar stock a wide range of pH meters. Scan to see the full range online.

OHAUS® ST10 pH Pen Meter

A new pen pH meter that is durable, practical and affordable.

• Simple operation in a slim and portable design

• Durably constructed to withstand wear and tear resulting from repetitive use

• Waterproof housing protects the meter in its working environment

• Range: 0.0 – 14.0

• Resolution: 0.1 pH

• Accuracy: 0.1 pH

PH240000

£59.00

OHAUS® ST20 pH Pen Meter

A new pen pH meter that is durable, practical and affordable.

• Simple operation in a slim and portable design

• Durably constructed to withstand wear and tear resulting from repetitive use

• Waterproof housing protects the meter in its working environment

• Range: 0.00 – 14.00

• Resolution: 0.01 pH

• Accuracy: 0.05 pH

• Calibration: 3 point

PH240010

£125.00

A few facts about electrolysis.

Electrolysis means splitting with electricity

It is completing an electrical circuit using free ions in a liquid or solution

It needs a power source (DC)

It needs electrodes: somewhere for the ions to go (be attracted to)

Electrolysis is used to ‘plate’ metal in industry, to extract metal from its ore, in the manufacturing of chemicals, and it is also employed in pH probes

Set up of electrolysis:

Power supply

Positive electrode (Anode)

Direction of (conventional) current flow

Direction of (electron) current flow

1. The electrolyte solution is added to a suitable container.

2. Electrodes and a power supply are added as in the diagram above.

3. The power supply is switched on and bubbles should appear at one of the electrodes.

4. Depending on the electrolyte and the electrodes used you may see: plating of a metal at one electrode, a diminishing electrode (as it is used in the reaction), gas produced at one electrode.

5. Adding a microammeter into the circuit, (in series) will indicate that current is flowing.

Want to find out more about how electrolysis works, including ideas about microscale and miniscale set ups?

Negative electrode (Cathode)

Electrolyte solution, containing ions

Electrolysis Cell

Each cell consists of 75 x 24 mm glass cylinder with 2 hole rubber stopper fitted with carbon electrodes. Electrical contact is made through the crocodile clips and a piece of insulating material between the electrodes prevents short circuiting. The gases evolved are collected in two 75 x 10 mm test tubes suspended over the electrodes by piece of wood and rubber bands (not supplied).

Electrolysis of water: the Hofmann voltameter - Although the Hofmann apparatus is filled with dilute sulfuric acid, it is actually used to demonstrate the electrolysis of water.

Electrolysing water splits the water molecules, H2O, into hydrogen, H2, and oxygen, O2.

Water

2H2O(l)

Hydrogen + Oxygen

2H2(g) + O2(g)

What you will see from the equation is that the volume of hydrogen is twice that of oxygen. Using the Hofmann voltameter will provide a visual demonstration that there are twice as many hydrogen atoms as oxygen atoms in water.

Hofmann Voltameter

The Hoffman Electrolysis Apparatus is used for the demonstration of the chemical composition of water and the production of gases through chemical reactions.

EL180875 Glass Stopcock

EL180877 PTFE Stopcock

Student Gas Voltameter

Platinum electrodes, with two 15 mL graduated test tubes. Mounted on moulded base fitted with two 4 mm banana sockets.

EL62520

£47.70

£68.95

£24.45

What you need to know about QUICKFIT®

QUICKFIT® ground glass joints were developed as an alternative to scientists using rubber bungs and glass and rubber tubing to connect pieces of glassware.

All QUICKFIT® glass items are manufactured from PYREX® borosilicate glass which is ideal for use over a wide temperature range, is highly resistant to chemical attack and can be used with most acids, alkalis, and organic solvents.

QUICKFIT® interchangeable conical joints are made using a two-stage grinding process that ensures the joints have a precision 1:10 taper and super-fine surface finish, resulting in joints that have an exceptionally good seal with a greatly reduced risk of joint seizure. The excellent surface finish also ensures that the joint will not leak and will be gas and vacuum tight.

QUICKFIT® sockets feature a rounded rim profile which gives extra strength to the joint and is less prone to chipping than a square rim profile.

One Piece Distillation Apparatus, QUICKFIT®

The one-piece construction means that the angle of the condenser, still head and receiver are pre-defined and optimised for vacuum distillation applications. Because there are no joints between the components, this assembly is vacuum, gas, and airtight, and is liquid leakproof.

QDA1/22

QUICKFIT® Microscale Organic Chemistry Kit

£125.75

The QUICKFIT® Microscale Chemistry Kit was designed to perform organic chemistry experiments, but on a much smaller scale.

QU130500

Conical joints are the most common type of ground glass joint and comprise a tapered (male) cone and (female) socket.

Search QUICKFIT® online to see the full range.

Search Quickfit

QUICKFIT® Liebig Condensers

The condenser is a tube with standard ground joints and a glass jacket. The cooling water is fed through the jacket in counter flow principle to increase the cooling capacity.

QC1/11SC

QC1/12SC

QC1/22SC

£243.40

Socket 14/23, cone 14/23, jacket length 160 mm, overall length 260 mm

Socket 19/26, cone 19/26, jacket length 210 mm, overall length 340 mm

Socket 19/26, cone 19/26, jacket length 400 mm, overall length 530 mm

£39.25

£42.20

£47.10

Safe operation for jointed glassware.

As with all laboratory glassware, there are some basic steps you need to follow to ensure the safe, sustainable use of jointed glassware:

Wash new glassware before first use to avoid contamination from packaging and examine it to ensure it is not scratched, chipped, cracked, or etched as defects will reduce its mechanical strength and may cause it to break during use. Whether transferring or using glassware, be careful not to scratch it, force it or handle it at the weakest points.

Other considerations for use:

While silicone grease may be used to help seal a joint, QUICKFIT® joints are designed to be used without it to avoid contamination.

Always check the maximum temperature guidelines - although the maximum recommended temperature for QUICKFIT® glassware is 500°C (for short periods only), the working temperature for other items –plastic connections, stoppers, tubing, etc, - could be much lower.

When using temperatures above 150°C, heating and cooling should be carried out in a slow and uniform manner to avoid breakage by thermal shock.

If using a hotplate, ensure that the top of the plate is larger than the base of the vessel to be heated. Never put cold glassware onto a pre-heated hotplate.

When using a Bunsen burner, employ a soft flame and use a wire gauze with a ceramic centre to diffuse the heat. This will avoid ‘hot spots’ developing in the glass which could cause it to break.

PYREX® borosilicate glass is microwave safe, but you must also ensure the contents and any attachments are as well.

Always wear appropriate PPE when conducting any laboratory experiments and always use any available safety equipment – safety screens etc.

QUICKFIT® Erlenmeyer Flasks

Erlenmeyer flasks feature a conical ground glass neck joint that is fully interchangeable with other jointed glassware with the same joint size.

QFE50/1 50 mL capacity, socket 14/23

QFE100/1 100 mL capacity, socket 14/23

QFE500/3 500 mL capacity, socket 24/29

We have a helpful guide to QUICKFIT® online! It covers the components you can select from and what they are used for, as well as more useful information about the when, why, and how of using jointed glassware.

Scan to view

Round Bottom Flasks are available with short or medium necks, one neck, two necks, and three necks and a variety of capacities and socket sizes.

£17.30

£19.00

£21.40

New school? Lab refurbishment? We are here to help and support you with your projects.

We can help you with large project unpacking!

Setting up a department and prep storage for a new building, new 6th form teaching rooms or a department refurb can be a time-consuming and daunting task. Not only deciding what you need, but once you have taken delivery of the goods and chemicals the task of unpacking products and sorting chemicals into a cohesive and safe storage system can feel overwhelming.

This is where we can help.

Working with one of our product specialist team right through from your initial inquiry to order placement and convenient delivery, we will be on hand to help you to unpack the full order and make sure that everything is stored correctly and in the right place.

Complete chemical store service.

Uniquely, our in-house expert can assist you with ordering all that you will need to stock your store, and then unpack and put away all chemicals following all Health and Safety requirements.

Our customers can take advantage of this unpack service for large orders: We are only satisfied when you are too!

Timstar can help with your unpack!

Scan to read about some of our other customers who have used our unpack service!

Unpack at Greenhead College, Huddersfield

At the Greenhead College, we took care of a large order that was ordered to stock up a number of teaching and preparation spaces. The Timstar team unpacked the order and were on hand to advise the department throughout, from box to shelf! Our product specialist Matt supported them with the equipment unpack, helping the staff to be as organised as possible before the start of their teaching.

Let us know if you are setting up or reorganising any part of your science department, and we will help you from start…to finish!

“We have just moved into a brand-new building expanding our capacity to fourteen labs teaching A level Chemistry and Biology. It was quite a task to fit out four labs from scratch but with Matt and the team at Timstar it all went smoothly.

From submitting a huge order for a quote to unpacking at the destination, we were provided with excellent support and service...”

Senior Chemistry Technician - Greenhead College

Melting point: All you need to know

What is a melting point apparatus?

It is an instrument used to determine the accurate melting point of a substance.

Melting point apparatus range from the Thiele tube to analogue, and now digital equipment.

Using a melting point apparatus.

A sample is placed into the apparatus in a sealed capillary tube. As the sample is heated it changes from solid to liquid and the precise temperature at which this change occurs is recorded.

One of the most basic ways to determine the melting point of a solid sample (or boiling point of a liquid) is the Thiele tube.

The tube is made of borosilicate glass with a hollow glass ‘handle’ to the side.

1. Clamp the Thiele tube securely and at a comfortable height.

2. Fill the tube with oil to just above the top join of the handle.

3. Add a few crystals of the sample to the bottom of a closed capillary tube and attach it to a thermometer (max 350°C) using a tight band.

4. Fix the thermometer/capillary tube into the Thiele tube such that the sample and the thermometer bulb are immersed in the oil (don’t immerse the band).

5. Use a holed bung sliced down one side so that the divisions on the thermometer are not obscured.

6. Heat the bottom arm of the handle with a low blue flame.

7. Heating the oil sets up convection currents and the sample in the capillary tube is heated slowly and evenly, the oil flows around the system without any additional stirring.

8. Note the temperature as soon as the crystals have melted.

9. Remove the heat and allow the system to cool completely before dismantling.

Thiele tube

More commonly, automated equipment is used to determine the melting point of unknown substances. These are extremely easy to use and give accurate results.

With these systems there is no external heating, and no oil is needed.

Sometimes the capillary tube containing the sample is inserted horizontally rather than vertically.

They are cold to the touch and pose no burn risk to the user, when used appropriately.

Economy Melting Point Apparatus

An entry level, simple to use melting point apparatus.

To get the sample into the capillary tube, push the open end of the tube into the sample. Tapping the capillary tube (vertically) onto the bench will help the sample travel down to the bottom.

Melting Point Apparatus, Cole-Parmer

Stuart MP-100

The MP-100 measures the melting point of chemicals from ambient to 250°C. The sample and melt process can be viewed via a magnifying lens, which is illuminated by bright LEDs. The melt temperatures can be recorded from the thermometer, positioned horizontal to the samples to allow simultaneous viewing.

ME10351 £600.00

That as the solid sample approaches its melting point it will pull away from the walls of the capillary tube and form a cone shape. This is called sintering.

Digital Melting Point Apparatus, Cole-Parmer

Stuart MP-200

Designed with safety and ease of operation in mind making it ideal for use in education. With this product, two samples can be tested simultaneously. It has built-in illumination, a 3-digit LED display and a viewing magnifying lens give clear viewing of samples. The temperature range is from ambient to 300°C.

ME10365 £755.00

Digital Melting Point Apparatus, Cole-Parmer

Stuart MP-200D-HR

Designed for maximum safety and ease of use. Select, measure, and display the temperature digitally, ensuring accuracy and avoiding the need for a glass thermometer. Test two samples simultaneously, viewing the melt via a magnifying lens with built-in illumination.

ME120200

Scan to learn how to use the Thiele tube for the determination of boiling point!

£995.00

ME220000 £235.00

What to do when you receive your electrode and how to maintain it.

When you receive your electrode the sensor zone will be protected by a cover which contains a soaker solution. Before using the electrode, rinse off the soaker solution and leave in deionised water for 15 minutes.

Occasionally during shipment, air bubbles may form in the glass bulb. If this happens, they can be removed by gently shaking the electrode in a downward movement.

Your electrode must be kept wet at all times. For short term storage the electrode may be stored in deionised water but for longer term storage it should be stored in a soaker solution.

** Information kindly supplied by Sentek Limited **

temperature range to 80°C. With free cleaning solution.

PH12192 Combination, plastic bodied

pH Electrode Cleaning Solution

A general purpose cleaning solution for pH electrodes.

PH25000

Buffer Solution Capsules

Sentek pH Electrodes

£138.65

Combination pH electrodes with BNC connector.

PH240100 Epoxy body £54.95

PH240110 Glass body £54.95

pH Electrode Storage Solution

A prepared storage solution to ensure maximum performance of your pH electrodes.

PH25010

£34.95

Simply split the capsule in two and add to 100 mL of deionised/distilled water and mix.

PH120120

PH120125

£32.80

Electrode Storage Bottles

A bottle to store your pH, conductivity and reference electrodes safely. Pack of 3.

PH240130 £14.45

Download the pH electrode calibration worksheet for the Phywe datalogging sensor

If you use pH meters, calibration is an important aspect of maintenance that helps to keep pH electrodes continually accurate.

Why is calibration important?

Calibration is a fundamental part of pH meter and electrode maintenance. Drift can occur in pH readings over time and through use due to electrode ageing and chemical exposure.

Calibrating takes account of these changes in the pH electrode and realigns the electrode and the pH meter using known reference standards which are known as pH buffer solutions.  Regular calibration is important for continued accuracy and repeatability.

How often should you calibrate?

How often you will need to calibrate depends on how often you use your meter, what substance you are testing and how well the electrode is cleaned and stored.  For example, if an electrode was being used to test clean water once a day, then monthly calibration would be suitable. An electrode used to test battery acid 20 times a day would require more frequent calibration to remain accurate.

Another factor in determining calibration frequency is the level of accuracy required. Many operators only need to measure pH to 0.1 of a unit and will not need to calibrate as frequently. An operator who requires 3 decimal point accuracy may need to calibrate daily or before each sample is tested. Using calibration solution

pH calibration solution, also referred to as buffer solution, is supplied ready to use in a range of pH values.

The most used solutions are pH 4 and pH 7, as 7 is the halfway point on the pH scale. Most pH measurements are performed in the acid range, making pH 4 the most suitable second buffer in many cases.

Solutions in other pH values are available for more specialist requirements or when measuring samples in the alkaline range, where it is common to choose a pH 10 buffer in place of pH 4.

Calibrating at pH 4 and pH 7 or pH 7 and pH 10 is known as a two-point calibration and is sufficient for most pH applications and accuracy requirements.

It is important that you use fresh solutions each time, and that you check to ensure your solutions are uncontaminated and in date before use.

** Information kindly supplied by Hanna Instruments UK**

Want to see the full range?

A water bath is a safe way to gently heat samples to your desired temperature and maintain them at it. Thermostatically controlled and suitable for short or long-term practical work they can be set at temperatures from ambient to 100°C.

Timstar stocks a range of analogue and digital water baths in sizes from 4 litres to 22 litres. Do remember that if you are using temperatures above 60°C we advise using a lid to maintain the temperature.

Search Water bath

Search Water bath

Clifton Unstirred Analogue Water Baths

Designed for general use and economically priced without compromising quality. An easy to use analogue dial pointer allows temperature setting graduated in 5°C divisions.

• Illuminated on/off switch and heater indication lamp

• Complete with a removable, ‘low’ height stainlesssteel perforated shelf

• Painted surfaces feature anti-bacterial finish, hygienic coating which actively inhibits bacterial growth, with good chemical resistance

• Temperature range: Ambient +5°C to 100°C

BA01870 4 litre

BA01871 8 litre

BA01872 14 litre

BA01873 22 litre

£335.00

£375.00

£385.00

£475.00

Clifton Unstirred Digital Water Baths

These digital water baths provide a stable temperature environment with a digital PID temperature control for precision. Featuring a bold LED display of measured temperatures in real time, with increments of 0.1°C. The easy to use controls are splash-proof, with touch keypad for setting temperature and indicator for heating and an over temperature alarm.

• Complete with a removable, ‘low’ height stainlesssteel perforated shelf

• Painted surfaces feature anti-bacterial finish, hygienic coating which actively inhibits bacterial growth, with good chemical resistance

• Temperature range: Ambient +5°C to 100°C

BA01876 4 litre

BA01877 8 litre

BA01878 14 litre

BA01879 22 litre

£465.00

£490.00

£515.00

£580.00

Benchmark™ Digital Water Baths

The Benchmark ™ digital water bath has been specifically designed for use in schools and colleges. UK designed and manufactured with a 304 grade stainless steel tank steel outer casing with antibacterial paint surface.

• Easy to use digital temperature control, from ambient +5°C to 95°C

• Temperature stability @45°C: ±0.25°C

• Temperature display: 1°C, auto-locking of set temperature, preventing inadvertent adjustment in use

• Low water run dry protection: Self resetting cut out

• Gated, large bore drain tap, for convenient bath emptying

• Stainless steel perforated base tray

BA140250 5 litre

BA140255 9 litre

BA140260 13 litre

BA140265 20 litre

£460.00

£485.00

£510.00

£575.00

TripleBaths feature three independently controlled, unstirred water baths in one unit.

Clifton Analogue TripleBath™

A triple water bath featuring three independently controlled unstirred stainlesssteel water baths, with individual thermostatic controls, in one unit, allowing each chamber to have a different temperature and water level.

• Illuminated on/off switch and heater indication lamp

• Complete with a removable, ‘low’ height stainless-steel perforated shelf in each tank

• Painted surfaces feature anti-bacterial finish, hygienic coating which actively inhibits bacterial growth, with good chemical resistance

• Temperature range: Ambient +5°C to 99°C

BA150300

NE1-4/4/4 £790.00

Did you know that you should initialise the controllers before using your Clifton Digital TripleBath™?

For temperature accuracy on digital models, it is important to allow the controller to initialise during the startup process before setting the temperature.

Here’s how to do it!

Before commencing, please ensure that all tanks are filled with water.

1. Switch on the GREEN mains switch of TANK 1 ONLY and immediately press and HOLD the P button until SLS is displayed then press the P button = 10.

2. Using the ▲ OR ▼ buttons, adjust the setting to 10.0 then press the P button to confirm the setting.

3. Press and HOLD the U button to return to the ACTUAL TEMPERATURE display.

4. Press the P button = SP.

5. Use the ▲OR ▼ buttons to adjust the SET TEMPERATURE to the required operating temperature then press the P button to confirm the setting.

6. The HEATER indicator should illuminate, and the water bath should begin to heat.

Repeat the steps above for Tank 2 then Tank 3, one at a time.

Once all of the settings are correct, you will be able to use all 3 tanks at the same time.

Clifton Digital TripleBath™

A triple water bath featuring three independently controlled unstirred stainlesssteel water baths, with individual digital thermostatic controls, in one unit, allowing each chamber to have a different temperature and water level.

• Easy-to-use digital controls, with up and down key pads, allow temperature setting

• Each tank has an illuminated on/off switch and heater indication lamp

• Complete with a removable, ‘low’ height stainless-steel perforated shelf in each tank

• Painted surfaces feature anti-bacterial finish, hygienic coating which actively inhibits bacterial growth, with good chemical resistance

• Temperature range: Ambient +5°C to 99°C

BA150306

BA150304

NE1D-2/2/2 Digital £820.00

NE1D-4/4/4 Digital £960.00

Our eyes are able to perceive different colours within the visible spectrum of light. White light is made of a mix of many different wavelengths of light, visible to our eyes as different colours (when the white light is split into those wavelengths through a prism).

What happens when light falls on surfaces? Why do we perceive the colours of objects that we do?

This has to do with the absorption and reflection of different wavelengths (colours) of light:

There are two colour palettes that we can see: primary and secondary colours

Primary colours are those that cannot be split any further and these are red, green, and blue

Mixing these colours of light will give white light (the presence of all the wavelengths of light)

Primary colours: green, red, blue

Secondary colours yellow, cyan, magenta

‘White light’ all wavelengths

FUN FACT!

As an object’s temperature increases, the energy it radiates is dominated by the shorter wavelengths of the spectrum. The sun has been measured at roughly 5,500°C and appears yellow. If the temperature increased it would appear bluer (more of the short wavelengths produced). If it lost temperature it would appear redder (longer wavelengths).

When (white) light reaches an object, the object will absorb some wavelengths of light and reflect others. The reflected light is what our eyes perceive.

White light reaches object

White light reaches object

Red light is reflected

Blue & green light is absorbed Red block

Secondary colours

White light reaches object

Blue light is reflected

Red & green light is absorbed Blue block

Green light is reflected

Red & blue light is absorbed Green block

Secondary colours: cyan, yellow, and magenta are made from mixing primary ones.

Blue and green make cyan; red and green make yellow and red and blue make magenta.

White light reaches object

Blue & green light is reflected (making cyan)

Cyan block

Red light is absorbed

LED Colour Mixing Apparatus

The LEDs can be projected onto a piece of paper or wall depending on whether you are doing a classroom demonstration or student bench top experiments. Each lamp is flexible and is connected to an individual knob that controls the brightness of the lamp

OP230100

£110.00

Newton’s Colour Wheel, Motorized

This motorized Newton’s colour wheel is useful for demonstrating that white light is composed of a combination of different spectral colours.

OP74610

£35.75

White light reaches object

Red & green light is reflected (making yellow)

Blue light is absorbed Yellow block

Colour Mixing Apparatus

An upright case contains three, high powered, accurately colour matched LEDs, each of which has adjustable brightness.

OP84760

Colour Mixing Box

£92.75

White light reaches object

Red & blue light is reflected (making magenta)

Magenta block

Green light is absorbed

This unit contains three coloured light sources (red, green and blue) projected onto a screen in overlapping circles. The unit is self-contained, meaning no setup is required, and can be used comfortably by 2-3 pupils at time.

OP155050

£21.20

To see what happens when shining a secondary coloured light onto a secondary coloured object, or how coloured filters affect the colour we see and lots more fun colour facts, visit the Resource Hub and search ‘colour’

Hooke’s law relates the force, mass, and extension of a material. Usually in school we look at spring extension, but it does apply to all materials if the forces and deformations are small and don’t exceed the elastic limit of the material.

Hooke’s Law

The force exerted on a spring is directly proportional to the extension of the spring.

This only applies within the elastic limit of the spring. If a spring is stretched beyond that limit, it will not return to its original shape because it has lost its elasticity, thus further force applied will not be proportional to the extension.  To overcome this part of the spring’s nature, a constant - the spring constant, which is different for each spring – is included in the equation:  F=kx

Where F = force, x = extension and k = spring constant

Sometimes the equation is written as F= -kx. The minus sign indicates a direction. This is because the force will be in the opposite (-ve) direction to the displacement (extension).

The spring constant is equivalent to the force per unit extension (nm-1), the larger the constant the less elastic (or stiffer) the material will be.

Hooke’s law investigations are present in both the GCSE and A level physics specifications, although sometimes the A level requirement is to test the elasticity of materials other than a spring. They will be identifying the spring constant in each case.

As well as the traditional method of investigating Hooke’s Law, it can also be done using the Phywe Cobra SmartSense force acceleration sensor. The FREE worksheet is included with the MeasureAPP software.

Cobra SMARTsense Force Acceleration Sensor

Ideal for measuring pushes and pulls within the classroom. Perfect for Hooke’s Law, g by freefall and more.Use this Cobra SMARTsense Force Acceleration sensor to measure the acceleration resulting from an external force.

• Quick and easy connection via Bluetooth and the free measureAPP

• Contains a USB-C rechargeable lithium polymer battery

• Up to 50 hours use on one battery charge

• Force:

o Range: ±50

N o Resolution: 30 mN

• Acceleration: o Range: ±16 g

o Resolution: 0.01 g

• Gyroscope:

o Range: ±34.9 rad/s o Resolution:

0.01 rad/s

• Sample rate: 1000 Hz

Want to find out more? Click here for more information about the Hooke’s Law experiment and the development of the spring balance.

How to use the weigh-below-hook on a balance!

Some balances feature an integral weighing hook on the underside of the balance. Useful for weighing items that do not fit particularly well on the top pan. For OHAUS® Scout SKX balances this is where they can be found:

Remove this plug to attach

Weigh hook is under this cover

Look on the underside of the balance and you will see the red rectangular battery housing

Check out the Resource Hub post on calibrating the OHAUS® balance!

Open this and a hook can be found on the underside

Remove this hook and remove the red rubber plug found in the top middle of the underside of the balance. The hook screws into this

Return the balance to the right way up, allowing space for the hook to hang freely

You can now use the hook to weigh irregular shaped objects

OHAUS® Scout SKX Balances

Designed for education applications, the OHAUS® Scout with large backlit LCD backed by education software and is the ideal balance for your classroom. It is built to endure demanding classroom applications with superior overload protection. Features including: faster stabilization time, increased capacity, multiple connectivity options and stackable design make Scout the best weighing experience for the next generation classroom.

120 g x 0.001 g

Students learn about the importance of resistance in a circuit and how it is related to current, voltage and charge. Here we explain how to choose and use the rheostat (variable resistor) in a circuit.

In science education, resistors are used to show the relationship between resistance, current and voltage (potential difference) in the circuit.

The equation relating these is given as: V=IR

Where:

V =  voltage (potential difference), in volts (coming from the power supply)

I = current running through the circuit (amps)

R = resistance (ohms).

With a constant potential difference powering the circuit, resistance is inversely proportional to the current in the circuit: If you increase the resistance, the current will go down (and vice versa).

For a table showing the different types of resistors and their circuit symbols, as well as lots more information about resistors and rheostats visit the Resource Hub.

Resistor colour codes

Most resistors used in school will be 4 or 5 colour banded resistors.

The colours represent the value of the resistor (using significant figures and a multiplier).

To understand how to read the banding on a resistor, search ‘Resistor’ on the Resource Hub

Cobra SMARTsense Current Sensor

Part of the Phywe range of datalogging sensors, exclusive to Timstar.

Rheostats, Sliding Contact

Consisting of heavily oxidised resistance wire wound upon vitreous enamelled steel tube and locked into place with ceramic cement, multi-leaf phosphor bronze heavy duty sliding contact on nickel plated rod. Robust enamelled diecast end stands and 4 mm socket terminals

EL18541 600 Ohm £37.60 EL18546 8.5 Ohm £37.60

EL18542 300 Ohm £29.10 EL18552 125 Ohm £39.90

EL18544 55 Ohm £37.60 EL18553 37 Ohm £44.70

EL18545 16 Ohm £37.60 EL18554 20 Ohm £52.50

What is a rheostat?

The slider is a moving connector. You move this along the coil to change the resistance in the circuit, by effectively changing the length of wire.

If you connect the circuit wires so that the top bar of the rheostat is excluded (so connect bottom left, A, and bottom right, B, terminals) the current will pass through all the coil, and you will have maximum resistance.

School Science Guide for Technicians Book

This handy guide provides a valuable resource for new school laboratory technicians, teachers without technical support and for experienced science technicians. It contains lots more information about resistors.

VI210000 £40.00

In its simplest form this is a long piece of wire wrapped around a cylinder, with connectors at either end, and a ‘slider’ on the top.

If you connect either end of the rheostat into the circuit (bottom left, A to top right, C) the current will pass through the coil and out at wherever the slider is, and on to the rest of the circuit (via the bar and terminal C). Moving the slider to make the length shorter will decrease the resistance in the circuit, and vice versa.

Note: The rheostat will work either way round. If it’s wired the opposite way then moving the slider along to seemingly increase the length, will actually decrease the turns and thus resistance.

Lascells cloud chamber – key

facts:

Supplied with low activity thoriated tungsten welding rod source

Requires isopropyl alcohol (propan-2-ol)

Peltier-cooled (no need for dry ice!) – tracks visible within minutes

How does it work?

Volatile isopropyl alcohol (propan-2-ol) is dispensed onto a felt bed which evaporates and turns to vapour.

The bottom of the chamber is cooled and as the vapour falls through the chamber it rapidly cools. This pushes the vapour into a supersaturated state which means it will readily condense given something to condense on to.

Charged, radioactive particles pass through the air, ionising air molecules and leaving them positively charged. These ions provide a surface for condensation to occur, and so small liquid droplets are formed around them, tracing out the paths of the radioactive particles.

What can I see?

You can see the paths of where the particles have been. You should be able to see both alpha and beta tracks from the thoriated tungsten rod.

Alpha: Typically thick traces as alphas are highly ionising. Tracks may become increasingly dense further from the source as the particles lose energy and ionise more air molecules. Tracks are usually straight – the relatively massive alpha particles are not easily deflected by collisions with air molecules. Track length can be up to 4-5 cm.

A cloud chamber enabled the discovery of the positron in 1932.

Beta: thin traces – electrons are less ionising. They are also smaller and lighter (easily deflected) and so follow curved paths.

What experiments can I do?

Absorption of alpha particles

Roll a thin cylinder of paper and place the thoriated tungsten rod inside. One sheet of paper should be enough to stop the alpha particles, leaving only beta able to pass through.

How radioactive is your physics lab?

Charge up an inflated balloon (rub it on hair/clothes), and stick it to the wall. After 20 minutes, pop the balloon and place it inside the cloud chamber. You should see a lot of alpha emissions. [The charged balloon captures daughter isotopes from the radon decay series, trapped on dust particles in the air].

Show us how radioactive your school is by tagging us on X @Lascells.

Kindly written by Dr Nichola Swann

Lascells Cloud Chamber

The Lascells cloud chamber is the perfect alternative to existing unreliable and time consuming dry ice variants. The chamber is self-contained and thermoelectrically cooled. The chamber requires no dry ice or water; the only setup necessary is the addition of isopropyl alcohol and connection to a mains socket.

RA220000

£520.00

Try different levels of the school (especially basements!) – you should see increased activity on lower floors as radon seeps into buildings from the ground.

Top tips for improving track visibility.

Charge the included polystyrene disk and place on top of the chamber. Remove and replace as necessary – this draws old ions away from the sensitive region, allowing fresh vapour to diffuse and restore supersaturation.

Use two thoriated tungsten rod sources to double up tracks – Timstar can help if you require extra sources!

Curriculum

GCSE Physics: Radioactive decay and nuclear radiation

A-Level Physics: Stable and unstable nuclei

Dr Nichola Swann is the Sales and Marketing Manager for Lascells. Her background is in Physics and she holds BSc and PhD degrees from Keele University. She has spent the last decade supporting practical science teaching in schools and universities in the UK.

Have you ditched the dataloggers because they are out of date, complicated to set up and the software costs a fortune?

Well, it’s time to think again!

Phywe dataloggers have the advantage over many in that they are completely ‘stand-alone.’ Buy as many (or as few) as you wish, there is no need to commit to a complete system!

The software is FREE to download on any computer/tablet you have and there is no central ‘box’/interface needed to connect the datalogger - completely wireless (and Bluetooth).

Historically, ticker tape timers were extensively used to calculate the speed (and thus acceleration) of moving objects: usually dynamics trolleys down ramps. However, ticker tape timers were notorious in their ability to not work, with inaccuracy and tape problems being among the issues.

Ticker tape timers are still in use today, especially for younger students, but when you need higher levels of accuracy the light gate has become a much better option for older students, and especially when doing the required practical for Newton’s second law.

changing mass)

OCR PAG3: Motion (3.1 acceleration of a trolley down a ramp)

EDEXCEL CP1: Investigating force mass and acceleration

Want to see our full range of datalogging sensors? Search SmartSense

Notes on using the Phywe photo (light) gates:

If using the Phywe photo (light) gates, they both must be in position and the distance between them measured

The dual photogate (DA220330) has an integral speed display and therefore can be used without the tablet/phone connection to the MeasureApp software. Light gates (DA220060) will need to be connected to the software as they do not have this display

There is a FREE worksheet on acceleration and how to perform the investigation using data logging included with the FREE MeasureAPP software

Frederiksen Linear Air Track

A superb quality air track made from square section aluminium extrusion with supporting “U” channel. Linearity is +/- 0.03 mm. Suitable for elastic and inelastic collisions, momentum, speed and acceleration measurement.

TI68740 Air track

FO110105 Air track accessories

TI68742 Air track blower

Cobra SMARTsense Photogate Sensor, Pair

This Cobra SMARTsense Photogate sensor pair allows precise time measurement of dynamic processes, including free fall, pendulum investigations and many more.

Cobra SMARTsense Dual PhotogateDouble Light Barrier

£550.00

£119.95

£262.50

• Range: 0 - ∞

• Resolution: 0.01 ms

• Sample rate: 1000 Hz

DA220060

This Cobra SMARTsense dual photogate sensor can be used to conveniently measure times, speeds, accelerations, or count events. Ideally suited for pendulum experiments or experiments on dynamics. Thanks to the integrated display, it can also be used stand-alone, without a digital terminal. For the full specification see our website.

DA220330

£225.00

£311.70

Timstar SuperTech meets 2024

Looking for a great value training day with workshops, a manufacturer’s exhibition, product experts, and networking opportunities?

We are delighted to be running two SuperTech Meets this summer at beautiful Stowe and our new venue, the fantastic Benenden School. Please register for your place as soon as possible. Spaces are limited and will be offered on a first-come, first-served basis.

Enhance your skills, connect with professionals, and explore science workshops at Timstar’s SuperTech Meets 2024! Join us at Stowe or Benenden School for insightful workshops, exclusive exhibitions, networking, and more...

Event Highlights

Insightful workshops: 3 workshops (A range of topics for teachers and technicians from beginners through to experienced).

Engage with suppliers: Discover new products in our marketplace.

Exciting raffle: Win prizes and giveaways.

Hot lunch and refreshments: A chance to chat and refuel!

Networking opportunities: Connect with local colleagues, professionals and suppliers.

Chat with the Timstar team: Connect with us directly.

Stowe School

Stowe, Buckinghamshire, MK18 5EH  2nd July 2024, 9:00 – 15:30

These events are the highlight of our summer! Booking is simple, visit our website for more information.

Benenden School

Benenden, TN17 4AA 9th July 2024, 9:00 – 15:30

Get ready for spring with FREE KS3 and KS4 downloadable worksheets!

Visit our Resource Hub and download today!

Dive into spring with our captivating practicals! Explore plant biology up close with activities like stomatal peel and leaf disc photosynthesis. Uncover secrets of plant reproduction with flower dissection and discover how plants respond to their environment with geotropism and phototropism.

Plus, NEW FOR 2024: Indulge in the delicious science of chocolate!

| Dissectionofamammaliankidney Kidneydissectionisausefultooltohelpunderstandhowtheorganfunctionsinrelationtofilteringwasteproducts fromthebloodandtheformationofurineanditisoftencarriedoutasateacherdemonstrationatGCSElevel.

Hooke’s Law

Hooke’s law relates the force, mass, and extension of a material. Usually in school we look at spring extension, but it does apply to all materials if the forces and deformations are small and don’t exceed the elastic limit of the material.

Humans,likeallmammals,havetwokidneys.

The force exerted on a spring is directly proportional to the extension of the spring.  This only applies within the elastic limit of the spring. If a spring is stretched beyond that limit, it will not return to its original shape because it has lost its elasticity, thus further force applied will not be proportional to the extension.

O F 2F 2x

KidneydissectionfeaturesintheWJECAlevel specification(practical26inthehomeostasisandthe kidneytopic)anditisexpectedthatthestudentswill dothedissectionthemselves,withsomeguidance. Otherspecificationsfocusonheartdissection.Shapedlikeakidneybean,andaboutthesizeof yourfist,theyaresitedeithersideofthespinejust belowtheribcage. Themainfunctionofthekidneyisasafilter, removingtoxicwasteproductsfromtheblood,but italsoregulatesthesoluteconcentrationofthe blood(osmoregulation).  Thekidneycontainsmillionsofnephronstocarry outthisprocessoffiltrationandosmoregulation, allwithagoodbloodsupply.Thestudents willlearnaboutultrafiltrationandselective reabsorptionalongtheloopofHenle,insideeach nephron. Otherfunctionsofthekidneyincludehormone production(reninisproducedwhichhelpsblood pressureregulation),acid-baseregulation,and, alongwiththeliver,glucoseregulation.  Kidneystonesarehardmineraldepositsthat accumulatewithinthekidney,andsometimescan blocktheureter(exittube)ofthekidneycausing pain,inflammation,andinfection.Thisisdueto ahighconcentrationofsalts/mineralsandwaste productsinthebloodcomparedtothevolumeof water.

To overcome this part of the spring’s nature, a constant - the spring constant, which is different for each spring – is included in the equation:  F=kx

48 | Hooke’s Law Cobra

the material will be. Hooke’s law investigations are present in both the GCSE and A level physics specifications, although sometimes the A level requirement is to test the elasticity of materials other than a spring. They will be identifying the spring constant in each case.

AswellasthetraditionalmethodofinvestigatingHooke’sLaw,itcan alsobedoneusingthePhyweCobraSmartSenseforceacceleration sensor.TheFREEworksheetisincludedwiththeMeasureAPPsoftware.

Want to find out more? Click here for more information about the Hooke’s Law experiment and the development of the spring balance.