Active Transport

Question 1

Is active transport an active or passive process?

Answer 1

Active (requires energy in the form of ATP)

Question 2

What type of protein is used in active transport

Answer 2

Carrier proteins which are specific to a particular molecule

Question 3

What is the definition of active transport?

Answer 3

The movement of particles against their concentration gradient from a region of low concentration to high concnetration, active transport requires energy in the form of ATP

Question 4

Describe how molecules/ions cross the plasma membrane by active transport

Answer 4

1. Active transport is the movement of particles against their concentration gradient using ATP
2. The carrier proteins take in the molecule from outside/inside the plasma membrane
3. The molecule binds to the carrier protein. ATP then binds to the carrier protein on the inside of the plasma membrane
4. The binding of the ATP and the molecules causes the carrier protein to change shape, so that the inside of the plasma membrane is open to the molecule but the outside of the plasma membrane is closed to the molecule

Question 5

Why do certain cells have a lot of mitochondria?

Answer 5

The cell does a lot of active transport and so requires a lot of ATP which is released in respiration

Question 6

When is bulk transport used?

Answer 6

When large substances* need to be moved across the cell membrane

*think substances in BULK

Question 7

Describe the process of endocytosis

Answer 7

1. Endocytosis requires energy in the form of ATP
2. The cell membrane folds over the substance to form an invagination, and then folds inwards to create a vesicle
3. The vesicle then moves towards the cell and moves the substance into the cytosol

Question 8

Describe the process of exocytosis

Answer 8

1. Exocytosis requires energy in the form of ATP
   2.Vesicles formed by the Golgi apparatus fuse with the cell membrane
   3.The contents of the vesicles are then released outside of the cell