Lipids Flashcards
What are fatty acids
Long chains of hydrocarbon ‘tail’ (nonpolar carbon to carbon bonds). COOH at one end ‘head’. Usually bonded to another group in vivo
What factors affect fatty acids melting point
length and saturation
What are the 2 numbering systems of fatty acids
systematic (C1 being COOH) and alternative (using w or n to denote methyl C - how far it is away from methyl group)
Features of triglycerides
nonpolar, vairable FAs on each glycerol, mostly saturated, liquids at room temperature
Simple triglycerides
3 identical fatty acid chains, 3 steric acid chains, create acid residues
Mixed triglycerides
named according to position on glycerol
Function of triglycerides
insulation, protection, store energy, oxidation state and water content
What are glycerophospholipids
3rd position on glycerol is occupied by a phosphate
What are sphingolipids
Membrane lipids. 2 other positions: fatty acid (via amino group, forms a ceramide), phosphate (frequently an amine alcohol is then attached to the phosphate e.g., choline)
What is sphingosine
instead of glycerol, an amine alcohol
What is sphingomyelin
usually 2 straight chains, gives tighter packing, stable membrane, alters fluidity, myelin sheath
Glycolipids
contains a carbohydrate, molecule is amphiphatic, specialised membrane component, recognition molecule, common in plant cells and nervous system
Steroids
only found in eukaryotes, 4 fused rings, relatively nonpolar
Cholesterol
most common steroid, amphiphatic, major component of animal plasma membranes, lesser amount in organelle membranes, structure rigid and flat, simvastatin
Cholesterols affect on membrane ridgity
increases ridgity at high temp, lowers degrees of freedom (restricting entropy/disorder) - restricts movement of neighbouring FA’s, reducing fluidity
