Cell Membrane Structure

Question 1

Explain how phospholipids form a barrier to dissolved substances

Answer 1

Hydrophilic head
Hydrophobic tail
Arrange into bilayer
Centre hydrophobic so dissolved substances cannot pass through

Question 2

How can the permeability of a cell membrane be measured in a lab

Answer 2

Beetroot
Rinse
5 test tubes 5 temps
Same length of time
Remove pieces 
Use colorimeter 
Higher the absorbable more poignant real eased the higher the permeability

Question 3

How does increasing temperature increase cell permeability

Answer 3

0 ridgid packed closely
Channel and carrier protiens deform
Ice crystals may break membrane when thaw
0-45 partially permeable cos fluid
Temp about 45 melt v permeable channel and carrier protiens deform

Question 4

Describe the fluid mosaic model

Answer 4

Phospholipids form bilayer
Fluid cos the phospholipids are constantly moving
Cholesterol present for structure
Protiens scattered through bilayer
Channel protiens allow large molecules and ions to pass through
Receptor protiens detect chemicals and signal way to respond
Glycoproteins
Glycolipids