Membrane Structure Flashcards
What are the intrinsic proteins?
Channel proteins
carrier proteins
glycoproteins
What are examples of extrinsic proteins?
Enzymes
Proteins that bind cytoskeleton to membrane
What theory describes the structure of the membrane?
Cell membrane theory
What informed the cell membrane theory?
Fluid Mosaic model
What was used to show the fluid mosaic model?
- TEM showing bilayer
- Fusion of human mouse cells with fluorescent markets in markers
- Study of ion channels
- SEN freeze fracture
- Changes in temp
- Endocytosis and exocytosis
- Associaton between proteins and membranes
How are the phospholipids arranged in the bilayer?
Hydrophobic fatty acid tails point to centre.
Hydrophilic heads point out.
What are phsophlipids made from?
1 phosphate group attached to Glycerol
2 fatty acids
What time does cholesterol have in the membrane?
Binds phospholopids together to add stabilty.
Prevents phospholopids forming a regular lattice helping fluidity.
Why is the phospholipid group in the phospholipid soluble?
Phospholipid is polar i.e. is charged
Why are the fatty acid tails insoluble?
Chains have no charge = are non polar
How do phosphlipids moves relative for act other within the membrane?
Diffuse laterally
How thick is a phospholipid bilayer?
7-10 nm
How many forms can the bikayer take?
3
What are the 3 forms the bikayer can take?
- Micelle - sphere
- Bilayer
- Liposome - Dohnut
What are the effects of cholesterol at different temperatures?
Low temps
Prevent crystallization
High temps
Prevents excessive fluidity
