Question 1
You are studying the toxic effects of a newly-discovered tropical plant extract. From preliminary studies, it appears that the toxin prevents H
+-dependent membrane transport. Explain which digestive processes may be impaired.
Question 2
Cholesterol is absorbed without being digested into smaller pieces. How does this compare to absorption of carbohydrates and proteins? Which characteristic of cholesterol suggests it would be transported by simple diffusion? What is the evidence that transport proteins are involved in cholesterol absorption? Does this discovery rule out transport by simple diffusion? Explain.