1
Q
what is the role of a membrane?
A
to control substances which pass through them
1
Q
cell membranes are —— ———
A
partially permeable
2
Q
what structure do cell membranes have?
A
a fluid mosaic structure
3
Q
what are cell membranes composed of?
A
- glyco proteins
- glyco lipids
- carbohydrares
- lipids
- proteins
4
Q
when was the fluid mosaic structure proposed?
A
1972
5
Q
outline the properties of a fluid mosaic model
A
- arrangement of molecules in the membrane
- phospholipids form a bilayer
- proteins are scattered through the bilayer, giving a mosaic affect
- some lipids have a polysaccharide attached, forming glycolipids
6
Q
name the different proteins that are involved within cell membranes and describe their roles
A
- Carrier and Channel proteins: allow large polar molecules to travel through the membrane
- receptor proteins: allow the cell to detect chemicals released from other cells
7
Q
name the different components of a cell membrane
A
- phospholipids, which form a bilayer
- cholesterol
8
Q
what is the function of cholesterol
A
cholesterol stabilises phospholipid tails, making them less fluid and more rigid, helping maintain the structure of animal cells
9
Q
A
