Transport across cell membranes

Question 1

What is the cell membrane composed of?

Answer 1

A phospholipid (fat) bilayer with protein molecules spread amongst them

Question 2

Functions of protein molecules in the membrane

Answer 2

Channel-forming proteins aid diffusion. Carrier proteins actively transport molecules across the membrane and provide structure. Enzymes speed up chemical reactions and receptors for antibodies or hormones

Question 3

What is the cell membrane?

Answer 3

Selectively permeable. Will only allow passage of smaller, soluble molecules through the membrane

Question 4

Diffusion

Answer 4

It’s the movement of molecules from a region of higher concentration of the molecules to a region of lower concentration, i.e. down a concentration gradient.

Question 5

What is diffusion an example of?

Answer 5

Passive transport (it does not require energy)

Question 6

What useful substances does diffusion provide?

Answer 6

Oxygen and glucose

Question 7

What waste product does diffusion get rid of?

Answer 7

Carbon dioxide

Question 8

Why is diffusion important to multicellular animals?

Answer 8

It plays an important role in the exchange of respiratory gases. It’s also essential for the movement of molecules of dissolved food

Question 9

Calculate % change

Answer 9

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