Active transport

Question 1

Define Active Transport

Answer 1

Active transport is the movement of molecules or ions into or out of a cell, from a region of lower concentration to higher concentration, using ATP and carrier proteins.

Question 2

Describe the process of Active Transport

Answer 2

Molecule or ion binds to the carrier proteins, the energy released from the hydrolysis of ATP causes the carrier protein to change shape and molecule or ion is transported across the membrane.

Question 3

Explain the process of Active Transport

Answer 3

• First, the molecule or ion to be transported binds to complementary receptor sites on a specific carrier protein.
• The phosphate remains bound to the carrier protein causing the protein carrier to change shape and opens up on the opposite side
• The phosphate molecule is released from the carrier protein. The carrier protein reverts to its original shape

Question 4

Contrast the processes of facilitated diffusion and active transport

Answer 4

• Facilitated diffusion involves channel or carrier proteins whereas active transport only involves carrier proteins;
• Facilitated diffusion does not use ATP / is passive whereas active transport uses ATP
• Facilitated diffusion takes place down a concentration gradient whereas active transport can occur against a concentration gradient.