Chapter 21.9, Problem 31P

Glutathione is a tripeptide whose function is to destroy harmful oxidizing agents in the body. Oxidizing agents are thought to be responsible for some of the effects of aging and to play a causative role in cancer.

Glutathione removes oxidizing agents by reducing them. In the process, glutathione is oxidized, resulting in the formation of a disulfide bond between two glutathione molecules. An enzyme subsequently reduces the disulfide bond, returning glutathione to its original condition so it can react with another oxidizing agent.

a. What amino acids make up glutathione?

b. What is unusual about glutathione’s structure? (If you cannot answer this question, draw the structure you would expect for the tripeptide and compare your structure with the actual structure.)