4.4 - Active Transport

Question 1

Factors affecting rate of active transport (4):

Answer 1

1. temperature - at higher temperatures, particles have more KE and travel faster
2. thickness of membrane - if thinner it has a shorter diffusion pathway
3. no. of carrier proteins - more means that more can be transported = faster rate of active transport
4. rate of respiration - more respiration, more ATP available for active transport

Question 2

Carrier proteins function and process of transport

Answer 2

• transport molecules or large molecules across the membranes

1. molecule binds to the protein
2. ATP binds to the carrier protein
3. Hydrolysis of ATP to ADP and Pi causes the carrier protein to change shape and releases the molecule or ion on the opposite side of the membrane
4. Phosphate ion is released from the carrier protein and causes the carrier protein to return to its original shape

Question 3

What is Active Transport?

Answer 3

• movement of particles from an area of low concentration to an area of high concentration
• active process and particles move against a conc. gradient