A clear understanding of chemistry is essential for the study of physiology. This is because organ functions depends on cellular functions, which occur as a result of chemical reactions.
Watson & Crick first proposed the double helix structure of DNA
Biochemistry = Chemistry of living things Matter = Anything that has mass and takes up space (Solids, liquids, gasses)
Element = Fundamental substance of matter (e.g. Carbon, Hydrogen, Oxygen)
Compound = Two or more different elements chemically bonded together (e.g. H2O = water, C6H12O6 = glucose) Molecule = two or more atoms chemically joined together. Molecules may be compounds (H2O = water molecule), or Molecules may be of the same element (H2= hydrogen molecule)
Our body consists of 11 bulk elements and 7 trace elements.
Bulk elements make up 99.9% of our body: Hydrogen (H) Nitrogen (N) Sodium (Na) Chlorine (Cl)
Oxygen (O) Sulfur (S) Potassium (K) Phosphorus (P)
Carbon (C) Magnesium (Mg) Calcium (Ca)
Trace elements make up less than 0.1% of our body: Cobalt (Co) Zinc (Zn) Manganese (Mn) Iron (Fe) Iodine (I) Copper (Cu) Fluorine (F) Learn each bulk element and trace element along with their atomic symbols shown in parentheses
All elements are arranged onto a Periodic table
Atoms Atoms are the smallest particles of an element that still have the properties of that element. Atoms are composted of 3 subatomic particles: Proton – carries a single positive charge Neutron – carries no electrical charge Electron – carries a single negative charge
An atom contains a central nucleus composed of protons and neutrons. Electrons orbit the nucleus.
Subatomic Particles Electrical Charge: Proton: +1 charge. Electron: -1 charge. Neutron: 0 charge
Atomic Mass: Proton: 1 dalton Neutron: 1 dalton Electron: 0
Most atoms contain equal number of protons and electrons, so an atom contains no overall net charge and is neutral.
Subatomic Particles Atomic Number: The number of protons in one atom. Atomic number identifies an element. Example. The atomic number of oxygen is 8. Oxygen, and only oxygen has 8 protons. Atomic Weight: The sum of protons and neutrons in one atom. Remember, the weight of electrons is negligible.
Isotopes Isotopes are atoms with the same atomic number, but different atomic weights. Isotopes occur because the number of neutrons of an element varies between atoms. Two isotopes of oxygen: Oxygen 16 (O16)
Oxygen 17 (O17)
protons: 8 electrons: 8
protons: 8 electrons: 8
neutrons: 8
neutrons: 9
Atomic Number:
8
8
Atomic Weight:
16
17
*The atomic weight of an element is an average of the isotopes present.
Understand the notations on a periodic table.
End of Section 1, Chapter 2