L03: The cell surface Flashcards
What is a cell membrane made of
Phospholipid bilayer with protein molecules scattered through it
What is the phospholipid composed of
A phosphate group
A head group
Glycerol
2 fatty acid tails
What is cholesterol made of
Polar head
Steroid ring
Hydrocarbon tail
Role of cholesterol
To main fluidity and rigidity at 37 degree celcius
What is the function of the membrane
- cell signalling
- exocytosis
- same cytoplasm share
What are the types of transport that occur in a cell membrane
- active
- passive
What are the two types of passive transport
- facilitated diffusion
- simple diffusion
What molecules are involved in simple diffusion
Simple uncharged molecules
What molecules are involved in facilitated diffusion
Large charged molecules
What protein allows facilitated diffusion
Ion channels which have a hydrophilic pore
What are the 3 main active transport proteins
- ATP driven pumps
- light driven pumps
- coupled proteins
Give an example of ATP- driven pump
Sodium potassium ATPase pump
Give two examples of coupled proteins
- uniporter
- symporter
What type of active transport does coupled proteins use
2nd active transport and this is using the concentration gradient of one molecule to bring in a different molecule
Example of a uniporter
Sodium and calcium in cardiac muscle:
1- 3 sodium bind and go into the cell
2- one calcium go out of the cell
