Exam 30: The Small Intestinal Phase of the Integrated Response to a Meal

Routine neonatal testing suggests that a baby lacks a transport protein responsible for the uptake of cysteine in the intestines and kidneys.However,although cysteine accumulates in the urine,its concentration in the plasma is normal when the child receives a diet containing protein.Which intestinal transporter probably provides for uptake of cysteine in this child?

A patient with severe Crohn's disease undergoes resection of her terminal ileum.After recovering from the surgery,she develops chronic diarrhea that is treated effectively with cholestyramine (a resin that can bind bile acids).If her Crohn's disease has not recurred,the diarrhea in the patient can probably be attributed to loss of which of the following membrane proteins?