digestion and absorption

Question 1

Suggest how a rabbit eating its own caecal droppings helps a rabbit’s digestion and absorption of dietary protein

Answer 1

• more undigested protein broken down
• more amino acids absorbed
• because protein passes again through ileum

Question 2

The action of carrier protein X (Na+/K+ pump) is linked to a membrane bound ATP hydrolase enzyme. Explain the function of this ATP hydrolase.

Answer 2

• ATP hydrolysed into ADP + Pi releases energy
• for active transport of Na+/K+ ions

Question 3

The movement of Na+ out of the cell allows absorption of glucose into the cell lining the ileum
Explain how

Answer 3

• Na+ conc gradient created
• Na+ moving in by facilitated diffusion brings glucose with it

Question 4

Use your knowledge of lipid digestion to explain why concentration of triglycerides decreased. Assume no absorption occurred.

Answer 4

• decrease in triglycerides due to lipase action
• decrease in triglycerides due to hydrolysis
• decrease in triglycerides due to hydrolysis of ester bonds