Lipid and Membrane Structure Flashcards
What are Lipids?
Lipids are insoluable in water, soluable in fat and organic solvents
They can store energy, precurse vitamins and are involved in membrane structure
What are triglycerides?
Hydrophobic
Made of 3 fatty acids and glycerol
Used for energy storage
Stored in adipose tissue
What are fatty acids?
long chain aliphatic carbonyl acids metabolised via the B-oxidation pathway to generate ATP
Fully saturated has no double bonds, unsaturated is one double bond and polyunsaturated is more than one double bond
Fluid-Mosaic model?
Island of protein in a sea of lipid
The 2 types of membranes?
Membranes can either be phospholipids (Glycerol + 2FA and phosphate containing group) or glycolipids (Glycerol + 2FA and Sugars)
Uses of Phospholipids?
Form spontaneous bilayer in aqueous environment
Composed of polar head group attached to phosphate group through backbone
Two fatty acyl side chains are linked to glycerol backbone via ester bonds
they are amphiphilic, polar head and nonpolar tail
What are the common head groups for phospholipids?
Choline, serine, ethanolamine and inositol
What is fluidity?
It is the ease at which molecules move around in the plane of the bilayer
How fatty acid length effects van der waals forces?
An increase in short fatty acids reduces the Van der Waals interactions in fatty acids and increases fluidity
Links in unsaturated FA reduce Van der Waals forces with other lipids and increases fluidity
What are lipid drafts?
They are specialised membrane microdomains, they are more ordered and less fluid due to an increased level of cholesterol and sphingomyelin. it allows an interaction between receptors and signalling molecules
3 types of membrane proteins?
Integral/intrinsic proteins are embedded in the lipid bilayer, spanning most of it
Anchored proteins are anchored to membrane by covalent bonds with fatty acids
Peripheral proteins attach to the membrane surface by Ionic interactions with integral proteins of polar head groups of phospholipids
