Membranes and transport

Question 1

How thick is a cell membrane

Answer 1

7.5 nm

Question 2

What passes through the lipid bilayer

Answer 2

lipid soluble substances and small uncharged particles eg, oxygen, carbon dioxide

Question 3

What are channel proteins

Answer 3

Allow for the uptake of ions and water soluble substances down a concentration gradient

Question 4

What are carrier proteins

Answer 4

Larger molecules attach to one side and then the protein changes shape to transfer them to the inside of the cell

Question 5

What are proteins in the cell membrane known as in the immune system

Answer 5

antigens

Question 6

In cells that operate active transport, what else might you find

Answer 6

Microvilli and mitochondria

Question 7

What is phagocytosis

Answer 7

the uptake of solid material that is too large to enter a cell by diffusion or active transport

Question 8

What is pinocytosis

Answer 8

the uptake of liquid material that is too large to enter a cell by diffusion or active transport

Question 9

What is exocytosis

Answer 9

the process by which substances leave the cells in a vesicle which travels to the cell membrane