1. How can people consume vastly different diets yet obtain adequate nourishment?

2. Why can’t a person gain nutritional benefits by finely grinding meat and injecting it into the bloodstream?

3. Name an organelle in human cells that has a function similar to protozoan intracellular digestion.

4. The protein in a hamburger is mostly myosin. Why doesn’t the human body simply use the cow version of myosin to build muscle tissue? What happens instead?

5. Orlistate is a new weight loss drug that inhibits the activity of lipases in the small intestine. Why would this be more effective than a drug that blocks absorption of proteins or carbohydrates? What might be aside effect of blocking fat absorption?

Additional Questions and Terms

1. Why can certain tripeptides cross intestinal lining cells, but others must be dismantled to dipeptides or even single amino acids to do this?

2. So-called fat-free cakes and cookies contain diglycerides which are technically not fats. In the small intestine, the diglycerides are repackaged into triglycerides. In which part of a villus would this probably occur?

3. Type II diabetes results from the inability of cells to recognize and bind insulin. Describe how a similar defect in leptin metabolism might cause obesity.