Co Transport

Question 1

Where is the high concentration of glucose?

Answer 1

In the epithelial cells as opposed to the lumen

Question 2

Steps of co-transport?

Answer 2

1) sodium ions are actively transported out of the epithelial cells into the blood by sodium-potassium pump
2) this reduces the concentration of sodium ions in the epithelial cell compared to the lumen
3) sodium ions can diffuse from the lumen down the concentration gradient into the epithelial cell
4) the sodium ions diffuse through a co-transporter protein (either glucose or amino acids attach) and are then transported into the epithelial cells against the concentration gradient
5) glucose then moves by facilitated diffusion from the epithelial cells against into the blood