4. Active Transport

Question 1

What is active transport?

Answer 1

It uses energy to move molecules and ions across cell membrane, usually against the concentration gradient.
Channel and co-transporters are involved.

Question 2

What do the carrier proteins do in active transport?

Answer 2

Molecules attaches to carrier protein, protein changes shape and this moves molecules across the membrane, releasing it to other side.

Question 3

What are the 2 main differences between active transport and diffusion?

Answer 3

AT moves solutes from low to high concentration.
FD they always move from high to low concentration.
AT requires energy and FD does not.

Question 4

What does ATP do in the cell membrane?

Answer 4

Undergoes a hydrolysis reaction.
Splits into ADP and Pi.
This releases energy so that solutes can be transported.

Question 5

What do co-transporters do?

Answer 5

Bind 2 molecules at a time.
Concentration gradient of one of the molecules is used to move the other molecule against its own concentration gradient.

Question 6

What does facilitated diffusion use that active transport doesn’t use?

Answer 6

Channel proteins.