1. Alcohol is hydrophobic and lipid soluble. What do these terms mean? How could alcohol affect the structure of cell membranes? Explain

2. People born with a particular genetic defect have low numbers of receptor proteins for cholesterol in their liver cells. How could this affect their blood cholesterol concentrations? What significance do you think this could have on their health?

3. Considering the three factors that affect the rate of diffusion through a membrane, explain how surgical shortening of the small intestine may help a person suffering from morbid obesity. (Hint: Food is digested and absorbed primarily in the small intestine.)

4. What kind of solution, in terms of its concentration, should be used to wet contact lenses? Could pure distilled water be used instead? Why or why not?

5. Cyanide is a drug that blocks the production of ATP. What effect would cyanide have on osmosis? On the movement of Na⁺ into a cell? On the movement of K⁺ out of a cell? Explain.

6. Antibiotics can have different mechanisms of action. An antibiotic called puromycin blocks genetic translation. One called actinomycin D blocks genetic transcription. These drugs can be used to determine how regulatory molecules, such as hormones, work. For example, if a hormone’s effects on a tissue were blocked immediately by actinomycin D but not by puromycin, what would that tell you about the mechanism of action of the hormone?

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