Topic 7- Membrane Transport

Question 1

Give an example of a hydrophobic molecule that can pass through phospholipid bilayer

Answer 1

Benzene

Question 2

What can be produced by bacteria which acts as an antibiotic and disrupts ion gradients

Answer 2

Ionophores

Question 3

Give an example of a carrier ionophore

What is it specific to?

Answer 3

Valinmycin

specific to K+ ions

Question 4

Give an example of a channel forming ionophore

Answer 4

Gramidicin A

Question 5

Aquaporins are abundant in which two places?

Answer 5

Erythryocytes + kidney cells

Question 6

Na/K ATPase structure

Answer 6

A2B2 tetramer

Question 7

Na/K ATPase allows how many ions in and how many ions out

Answer 7

3Na+ out

2K+ in

Question 8

Give an example of an antiport

How many enter / leave

Answer 8

Na/Ca exchanger

3Na enter
1x Ca leave

Question 9

What function does cardiac glycosides have?

Answer 9

Inhibits Na/K ATPase

Question 10

Cardiac glycosides increase what (2) by doing what?

Answer 10

Inhibition of ATPase increases concentration of Na intracellulaly

Exchanger slows leading to increased Ca intracellulaly

Question 11

SGLT1 can be found where? Which membrane

Answer 11

Intestinal lumen side of intestinal epithelial cell

Apical membrane

Question 12

Role of SGLT1

Answer 12

Transports glucose + Na into epithelial cell

Question 13

GLUT 2 can be found on which membrane

Answer 13

Basolateral membrane

Question 14

Why is sodium given with glucose as an oral rehydration therapy

Answer 14

glucose follows Na into epithelial

increased osmotic pressure in cell leads to H2O following

Question 15

Constitutive exocytosis occurs where?

What is its role

Answer 15

Occurs in all cells

Secretes proteins / PM proteins

Question 16

Regulated exocytosis occurs where? (2)

What is it dependent on?

Answer 16

Neuronal / pancreatic areas

Ca2+ dependent

Question 17

Name a protein found in receptor mediated endocytosis

Answer 17

Clathrin