Lipids and cell membranes Flashcards
What is the role of lipids?
- sources of energy
- form membranes
- participate in cell signalling
What is the role of fatty acids?
principle store of energy
What is the structure of fatty acids?
carboxyl group with long hydrocarbon chain
Explain fatty acid nomenclature
- carbon atoms:double bonds ratio tells us if fatty acid is saturated, unsaturated or polyunsaturated
- double bonds are number using ‘Δ9’, ‘Δ12’
What are examples of sterols?
- bile acids
- steroid hormones
- vitamins
- cell membranes
What is the most common inherited disorder in lipid pathways?
Gaucher’s
What are the lipids found in membranes?
phospholipids
glycolipids
sterols
What does amphipathic mean?
containing hydrophobic and hydrophilic ends
What is the structure of membrane lipids?
- hydrophobic tail
- hydrophilic head
Why are membranes important?
- compartmentalisation
- highly selective membranes
- sensors to respond to internal and external conditions
What is the fluid mosaic model?
- phospholipid bilayer is fluid matrix
- lipids and proteins can undergo rotational and lateral movement
- peripheral and integral proteins
How is asymmetry generated?
lipids transferred to other side using flippases
Where does membrane synthesis occur?
in the ER
What is vesicle trafficking?
bits of membrane pinch off from the ER to form vesicles and then fuse with other membranes
What is exocytosis?
- delivery of lipids and membrane proteins to cell membrane
- allows movement of other molecules out of cell
