0228 - Principles of Membrane Transport - EG

Question 1

List some various ways of transport across membranes and whether each is passive or active.

Answer 1

simple diffusion, passive; channels, passive; ATP pumps, active; transporters: uniporters, passive; symporters, active; antiporters, active.

Question 2

Are channels, pumps, or symporters the fastest in terms of the number of ions that can flow through these per second?

Answer 2

Channels are the fastest

Question 3

What type of transport facilitates the movement of glucose from the lumen into the cells of the small intestine?

Answer 3

2Na+/glucose symporter. The low concentration of Na+ intracellularly is maintained by the Na+/K+ ATPase constantly pumping Na+ extracellularly, thereby creating the drive for Na+ to move from the lumen into the cell, which glucose is linked to (symporter)

Question 4

What type of transport facilitates the movement of glucose from the cells of the small intestine into the blood?

Answer 4

GLUT2