Co-transport

Question 1

What is cotransport?

Answer 1

An active method of transporting remaining glucose molecules in lumen (from digestion) into ileum cell when the concentration gradient falls so facilitated diffusion cannot occur

Question 2

Establishing a concentration gradient of N+

Answer 2

Na+ ions are actively pumped out of cells into blood by Na+K+ATPase protein pump
This is active transport
So there is a higher concentration of Na+ outside of cell than inside

Question 3

Movement of Na+ and glucose together

Answer 3

A cotransporter protein facilitates the diffusion of these Na+ ions down their concentration gradient into ileum cell and pulls in glucose molecules against their gradient at the same time (using energy from conc gradient of Na+ ions)

Question 4

How does glucose leave the cell?

Answer 4

Glucose can passively diffuse out through carrier proteins of cell into blood by facilitated diffusion down its conc gradient to maintain a concentration gradient of glucose lower inside cell and higher outside

Question 5

What is the benefit of cotransport?

Answer 5

Maximum absorption of glucose from lumen into cells then into blood