Cell Membrane

Question 1

Why is the cell-surface membrane partially permeable

Answer 1

Allows some molecules through but not other

Question 2

How can substances move across the cell-surface membrane

Answer 2

Diffusion, osmosis and active transport

Question 3

Components in the phospholipid bilayer

Answer 3

•Phospholipid
(-Fatty acid tail
-Phosphate head)
•Proteins
(-carrier protein
-channel protein)
•Glycoprotein
•Glycolipid
•Cholesterol

Question 4

What is a phopholipid

Answer 4

•Has a phosphate hydrophilic head
•Has a fatty acid hydrophobic tail
•Heads face the water
•Hydrophobic inside so water-soluble substances cant diffuse through it

Question 5

Explain cholesterol

Answer 5

•Gives the

Question 6

3 factors the effect cell membrane permeability

Answer 6

• Temperature: high temperature denatures membrane proteins / phospholipid molecules have more kinetic energy & move further apart.
• pH: changes tertiary structure of membrane proteins.
• Use of a solvent: may dissolve membrane.