Movement by active transport 2.5.4

Question 1

Define active transport

Answer 1

A process that involves the movement of substances against their concentration gradient, involving the use of carrier proteins and ATP.

Question 2

State 2 processes that involve active transport

Answer 2

• Absorption of mineral ions by plant roots
• Exchange of sodium and potassium ions in neurones and muscle cells.

Question 3

Describe how carrier proteins aid the process of active transport

Answer 3

• Have specific sites for certain molecules/ions
• Have a region that binds and allows the hydrolysis of a molecule of ATP, to release energy
• This energy helps the carrier protein to change shape to move from one side of the membrane to the other.

Question 4

Define bulk transport

Answer 4

The transport of large molecules across the cell membrane

Question 5

What are the two types of bulk transport?

Answer 5

• Endocytosis
• Exocytosis

Question 6

Does bulk transport require ATP?

Answer 6

Yes, due to the energy required to change the shape of the membrane.

Question 7

Define endocytosis

Answer 7

A process which involves the transport of large particles or fluids into cells, using ATP.

Question 8

Define exocytosis

Answer 8

A process which involves the transport of large substances out of cells, using ATP

Question 9

State the two types of endocytosis

Answer 9

• Phagocytosis - ingesting solid matter
• Pino(endo)cytosis - ingesting liquid

Question 10

Give an example of exocytosis

Answer 10

At synapses to release neurotransmitters

Question 11

Give an example of endocytosis

Answer 11

Phagocytosis - immune response

Question 12

When is ATP needed during exo/endocytosis

Answer 12

To fuse the membranes together as well as moving the vesicles.