Lipids Flashcards
Describe fatty acids
Long hydrocarbon chains -carboxyl end - methyl end PKa 4.7-5 Length and saturation affects melting point
Saturated
No double bond
Unsaturated
Double bond present = kink
Naming system of fatty acids
(X:Y(n-Z)
X = number of carbons in chain
Y = number of double bonds
Z = position of first double bond counting from CH3 end
Describe a triacylglycerol
- 3 fatty acids joined via ester bond to a glycerol
- non polar
- mostly saturated
- solid at room temp
- found in animal fats e.g. butter
Recommended vs modern diet of triacylglycerols
Modern = 15:1 (omega 6 : omega 3) Recommended 2-4 : 1 - reduce inflammation -reduced risk of breast cancer -reduces morality risk from cardiovascular diseases
Functions of triacylglycerols
Insulation
Protection
Store energy
Simple TAG
2 identical fatty acid chains
Mixed TAGs
3 different fatty acid chains
Name them according to their position
Describe phospholipids
Phosphate found on 3rd position of glycerol
Ampholytic (can be basic or acidic)
Sphingolipids
Found in the membrane
Sphingosine replaces glycerol
Fatty acid attaches to sphingosine via an amino group = ceramide
Phosphate frequently has amino alcohol attached
Sphingomyelin
25% all human lipids: in myelin sheath
- only 2 straight chains = tighter packing and increased stability
Describe glycolipids
Contain a carbohydrate e.g. galactose or glucose
Amphipathic (hydrophobic and hydrophilic parts)
Specialised membrane component
Common in plant cells and cells of nervous system
act as recognition molecules e.g. blood groups
Describe steroid
Only found in eukaryotes
4 fused rings
Relatively polar
Cholesterol = most common steroid
Describe cholesterol
Most common steroid Amphipathic (hydrophobic/Philic) Major component animal plasma membranes Structure rigid and flat Membrane fluidity increases with high temp
