CMB1004/L07 Transport II

Question 1

What are the 2 major classes of transport proteins?

Answer 1

Carrier & channel proteins

Question 2

Describe how carrier proteins work.

Answer 2

Bind solute on one side of membrane and deliver it to other side by conformation change in protein

Question 3

Describe how channel proteins work.

Answer 3

Form hydrophilic pores in membrane through which solutes can pass through

Question 4

Give 2 examples of passive transport.

Answer 4

Simple diffusion
Facilitated diffusion

Question 5

What is a carrier protein that transports one substrate called?

Answer 5

Uniporter

Question 6

What is the direction of transport determined by in facilitated diffusion?

Answer 6

Concentration gradient across membrane

Question 7

How many sodium and potassium ions does Na+/K+ATPase transport at once?

Answer 7

3 Na+ out
2K+ in

Question 8

Describe primary active transport.

Answer 8

Uphill transport coupled directly to hydrolysis of ATP

Question 9

Describe secondary active transport.

Answer 9

Uphill transport of target molecule coupled to downhill transport of another molecule

Question 10

What is a symport protein?

Answer 10

A protein that transports the primary molecule and co-transported molecule in the same direction

Question 11

What is an antiport protein?

Answer 11

A protein that transports the primary molecule and co-transported molecule in opposite directions

Question 12

Name 2 common primary active transporters.

Answer 12

Na+/K+-ATPase
CA2+-ATPase
H+-ATPase (proton pump)

Question 13

Name 2 common secondary active transporters.

Answer 13

Na+-glucose
Na+-amino acid
Na+-Ca2+ exchanger

Question 14

What is primary active transport?

Answer 14

Transport resulting from energy directly from ATP

Question 15

What is secondary active transport?

Answer 15

Transport resulting from potential energy stored in a concentration gradient