Lipids and lipoproteins Flashcards
What are lipids
Chemical compounds characterised by high hydrophobicity
What are lipids soluble in
Organic solvents (acetone, chloroform)
Which classification of lipids do lipoproteins fall under
Compound lipids
Which classification of lipids do triglycerides fall under
Simple lipids
What classification of lipids do alcohol and fatty acids fall under
Derived lipids
What are the 4 forms of plasma lipids
Fatty acids
Triglycerides
Phospholipids
Cholesterol
What are fatty acids
Reduced linear hydrocarbon chains with a carboxylate group on the end
What are the 2 groups of fatty acids
Saturated and unsaturated
What do saturated fatty acids contain
Only single bonds and are saturated with hydrogen
Are saturated or unsaturated fatty acids more common in nature
Unsaturated
What are triglycerides
Esters between glycerol & 3 fatty acids
What are the functions of triglycerides
Energy storage, transport, insulation
What do phospholipids contain
Glycerol, 2 fatty acids, phosphate & nitrogenous base
What does the synthesis of cholesterol involve
Synthesis of 25 separate enzyme steps beginning with Acetyl CoA
What is most cholesterol in the blood present as
Esters
What form is most cholesterol in cells and tissues
Free form
What do lipoproteins do
Provide a water-soluble means of transport hydrophobic lipids
Where are lipoproteins synthesised
In the liver or intestine
What are lipoproteins regulated by
Apolipoproteins
What are the different types of lipoproteins
Chylomicrons, VLDL, LDL, HDL
What are the functions of chylomicrons
Transport exogenous lipid from intestines to all cells
What is the function of VLDL
Transport of endogenous triglyceride
What are the functions of LDL
Energy, cell replication, integrity and uptake
What is the function of HDL
Transport of cholesterol and cholesterol esters to the liver
What are the functions of apolipoprotein A & where do they occur
Cofactor for LCAT
Occur in chylomicrons & HDL
What are the functions of apolipoprotein B & where do they occur
Secretion of chylomicrons & VLDL
Binds LDL to receptors
What are the functions of apolipoprotein C & where do they occur
Cofactor for lipoprotein lipase
Occur HDL, VLDL, chylomicrons
What are the functions of apolipoprotein E & where do they occur
Binding of IDL to receptors
HDL, VLDL, chylomicrons
