1.3 - Membrane Structure

Question 1

Key components of a plasma membrane structure (4)

Answer 1

Phospholipids 
Integral proteins
Peripheral proteins
Cholesterol
Glycoproteins

Question 2

Name the two parts of phospholipids and their features

Answer 2

1) Phosphate head: hydrophilic, polar

2) Phosphate tail: hydrophobic, non-polar

Question 3

Define the term amphipathic and give an example.

Answer 3

• An amphipathic molecule has both polar and non-polar regions
• This means it must form a bilayer

EG: phospholipid

Question 4

Features/function(s) of cholesterol (4)

Answer 4

• reduces membrane fluidity by reducing movement of phospholipid tails
• reduces permeability to some solutes
• only in animal cells
• steroid, amphipathic

Question 5

Function/features of proteins (2)

Answer 5

• ensure right molecules go in/out of cell

- glycoproteins have carbohydrate chain attached

Question 6

Functions of membrane proteins

Hint: CCCHIP

Answer 6

C ell adhesion
C ell-to-cell communication
C hannels for passive transport
H ormone binding sites
I mmobilized enzymes
P umps for active transport