4.5 Co-transport and absorption of glucose in the ileum

Question 1

What lines the epithelial cell walls in the ileum? Why are they useful?

Answer 1

Microvilli
They increase the surface area for the insertion of carrier proteins through which diffusion,facilitated diffusion and active transport can take place.

Question 2

What is the role of diffusion in absorption?

Answer 2

Diffusion maintains a conc. gradient between the ileum and blood so more products can be absorbed.

Question 3

What is the actual mechanism by which glucose and amino acids being absorbed from the small intestine into the blood an example of?

Answer 3

Co-transport
(Sodium-Potassium Pump)

Question 4

How does the sodium-potassium pump work?

Answer 4

• Sodium ions are actively transported out of cells into the tissue fluid
• glucose or amino acids attach to sodium and enter cells via facilitated diffusion
• glucose or amino acids diffuse into capillary