Active transport

Question 1

What is active transport?

Answer 1

Active transport is the movement of particles from an area of low concentration to an area of high concentration against the concentration gradient

Question 2

Is active transport a passive or active process?

Answer 2

Active as it requires energy from respiration in the form of ATP

Question 3

What proteins are involved in active transport?

Answer 3

Carrier proteins

Question 4

How are ions / molecules transported via active transport?

Answer 4

1) The molecule or ion binds to the carrier protein
2) On the inside of the cell, ATP binds to the carrier protein causing the hydrolysis of ATP to ADP + phosphate
3) The energy release causes the carrier protein to change shape and open to release the molecule or ion to the opposite side of the membrane
4) The phosphate is released from the carrier protein, reverting it back to its original shape to be used again
5) The phosphate will recombine with the ADP to form ATP

Question 5

What are the 4 factors that affect the rate of active transport?

Answer 5

• Temperature
• Thickness of membrane
• Number of carrier proteins
• Rate of respiration

Question 6

How does the temperature affect the rate of active transport?

Answer 6

At higher temperatures, particles have more kinetic energy and travel faster
Respiration also increases with temperature
Very high temperature denature carrier proteins decreasing the rate of active transport

Question 7

How does the thickness of the membrane affect the rate of active transport?

Answer 7

Particles will travel shorter distances through thin exchange surfaces so the rate of active transport will increase

Question 8

How does the number of carrier proteins affect the rate of active transport?

Answer 8

The more carrier proteins, the faster the rate of active transport

Question 9

How does the rate of respiration affect the rate of active transport?

Answer 9

The more respiration, the more ATP available for active transport