Digestion

Question 1

The diagram shows the co-transport for the absorption of amino acids into the blood by a call lining the ileum.

(Na+ co-transport out by active transport)

The addition of a respiratory inhibitor stops the absorption of amino acids. Why?

Answer 1

• less ATP produced
• Na+ not moved out of cell
• no diffusion gradient for Na+ to move out of cell with amino acid.

Question 2

How is the golgi body involved in the absorption of lipids

Answer 2

• modifies/processes triglycerides
• combines triglycerides with proteins
• processes, packages and releases by exocytosis
• forms vesicles

Question 3

Describe the processes involved in the absorption and transport of digested lipid molecules from the ileum into lymph vessels

Answer 3

• micelles contain bile salts and fatty acids
• make fatty acids soluble in water
• fatty acids are absorbed by diffusion
• triglycerides are reformed in cells
• vesicles move to cell membrane and triglycerides exit the cell via exocytosis

Question 4

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

explain how

Answer 4

• This maintains a concentration gradient for Na+
• Na+ moving in by co-transport brings glucose with it

Question 5

Describe the role of micelles in the absorption of fats into the cells lining the ileum

Answer 5

• Micelles contain fatty acids and bile salts
• They make fatty acids more soluble
• Bring fatty acids to the lining of the ileum
• Maintain higher concentration of fatty acids to the cell
• Fatty acids are absorbed by diffusion