Properties and Function of Lipids

Figure 23.

COURSE QUIZZES

1. You are trying to dissolve a substance in water. Which substance will least likely dissolve in water?

A. Benzene B. Ethanol C. Hydrochloric acid D. Potassium chloride

2. What major property of water accounts for the fact that a leaf will remain on its surface?

A. Heat of vaporization B. Capillary action C. Decreased solid density compared to liquid density D. High surface tension

3. When looking at a tube of water in a narrow tube, what shape will the meniscus be?

A. Convex B. Concave C. Flat D. Undulant

4. Hydrogen bonding is best done between hydrogen and an electronegative atom. According to the periodic table showing electronegativity, which molecule would best form a hydrogen bond with a hydrogen atom?

A. Carbon B. Oxygen C. Chlorine D. Fluorine

5. Which element inside living organisms is found to be the most prevalent by weight?

A. Hydrogen B. Carbon C. Oxygen D. Nitrogen

6. According to the number of atoms, which element is seen most commonly inside living organisms?

A. Hydrogen B. Carbon C. Oxygen D. Nitrogen

7. Which biological molecule is most responsible for creating and defining the genetics of the cell itself?

A. Lipids B. Carbohydrates C. Proteins D. Nucleic acids

8. Which biological molecule is most likely to be an enzyme?

A. Lipids B. Carbohydrates C. Proteins D. Nucleic acids

9. Which biological molecule is used as a rapid source of energy for the cell?

A. Lipids B. Carbohydrates C. Proteins D. Nucleic acids

ANSWER KEY: CHAPTER EIGHT

1. Answer: c. Living things put energy into the environment, naturally disrupting a natural downward trend that results in decreased chaos and decreased entropy in the system. 2. Answer: a. Sunlight puts energy into the ecosystem, allowing plants to grow and add to their structure, which would decrease the entropy of the environment. The other choices are decaying or destroying forces that would increase entropy. 3. Answer: d. Wind will spread pollen and seeds that will tend to scatter them and increase the biodiversity of many parts of the world. 4. Answer: a. Directional selection involves the favoring of an extreme or the fittest of the organisms being at one extreme end of the spectrum. 5. Answer: a. An ecological pyramid is a pyramid that shows the different trophic levels with things like energy levels, biomass, and numbers of organisms represented per level. 6. Answer: c. The tertiary consumer at the top of the pyramid is most affected because of issues like biological magnification that affects higher-order consumers the greatest. 7. Answer: b. Each of these is an untrue statement about human population density except that, because of rising density in humans, there is increasing strain on the population. 8. Answer: d. Each of these is a negative impact on the population as the density of human population gets greater. 9. Answer: b. With mutualism, the interaction between both species is positive so that both benefit from the relationship. 10. Answer: c. With commensalism, one organism benefits but the other neither benefits or is harmed because of the disparity between the two types of interactions between species members.

ANSWER KEY: COURSE QUIZZES

1. Answer: a. Each of these is a polar molecule that will easily dissolve in water with the exception of benzene. Benzene is not polar and therefore will not dissolve well in water as its solvent. 2. Answer: d. It is the high surface tension of water that most contributes to the fact that a leaf or perhaps a spider will sit on the surface of the water rather than sinking. 3. Answer: a. The meniscus will be concave with rising of the edges of the water surface near the edges of the tube where the water adheres to the surface of the tube, causing it to rise above the water in the middle of the tube. 4. Answer: d. Fluorine is the most electronegative atom so it would be the atom that will best participate in hydrogen bonding with a hydrogen atom. 5. Answer: c. These represent the most prevalent elements inside the human body but, if you go by weight, oxygen is considered the most prevalent by weight in the body. 6. Answer: a. Hydrogen atoms are very small but the molecule itself is very prevalent in living systems, being the most prevalent atom by number of atoms in living systems. 7. Answer: d. The genetics of the cell involve the nucleic acids, which in most living things involves the DNA polymer. 8. Answer: c. Almost all enzymes in the cell are made from polypeptides or proteins. 9. Answer: b. Carbohydrates, mainly simple sugars, are used as rapid sources of energy in the cell. Sugar is the main molecule used to create the energy molecules of the cell through various biochemical pathways. 10. Answer: a. Each of these is considered a monosaccharide except for sucrose, which is a typical disaccharide, often referred to as table sugar. 11. Answer: a. Starch is a polymer of glucose that is made by plants and used by animals of all types in order to be used for animal cellular energy. It comes from the glucose molecules made in the photosynthetic process. 12. Answer: c. Glycogen is the form of glucose storage polymer found in humans and in most animals. It is found in the liver and muscles where glucose can be released from it when glucose levels are low or when glucose is most rapidly needed.