Chapter 4- Cell Membranes

Question 1

What is active transport?

Answer 1

Movement against the conc grad
Using energy from ATP
via a carrier protein

Question 2

What is co-transport?

Answer 2

2 molecules moved via a carrier protein
One piggybacks
1 against conc grad one with conce grad

Eg) Na+ and glucose

Question 3

what is a hypERtonic solution?

Answer 3

water potential is lower outside

water moves out by osmosis

Question 4

what is a hypOtonic solution?

Answer 4

water potential is higher outside so water moves in by osmosis

Question 5

what happens to water potential when you add sugar?

Answer 5

decreases (more negative)

Question 6

what is the difference between channel and carrier molecules?

Answer 6

carrier - alter shape to allow molecules through

channel - water soluble molecules go through

Question 7

what molecules can directly diffuse across cell membranes?

Answer 7

small non polar

Question 8

what cannot diffuse directly across the phospholipid bilayer?

Answer 8

large polar molecules

Question 9

Describe the process of glucose/sodium cotransport

Answer 9

Sodium potassium pump between epithelial cell and capillary creates low concentration of sodium in cell.
Sodium moves into the cell from the lumen by fac diff, down the conc grad , co transporting glucose.
Glucose is absorbed into the capillary by fac diff