Exam 6 Flashcards
Lipids are
Fatty acids linked to the backbone of glycerol and phospholipids by an ester bond, albumin bound
Lipid composition
Hydrocarbon chains of various lengths and carboxylic acid chain
Lipid classifications
Saturated or unsaturated, monounsaturated or polyunsaturated, cis or trans configuration
triglycerides
Contains 3 fatty acid molecules attached to 1 molecule of glycerol by ester bonds
Triglycerides containing saturated fatty acids
Solid at room temp
triglycerides containing unsaturated fatty acids
Form oils at room temp
Triglycerides from plants
Rich in polyunsaturated fatty acids
Triglycerides from animals
Mostly saturated fatty acids
Phospholipids
2 esterized fatty acids and a hydrophilic phospholipid head group attached by ester bonds, amphipathic
Most common phospholipid
Phosphatidylcholine
Cholesterol
Unsaturated steroid alcohol with 4 rings and C-H side chain, amphipathic liquid found on surface of lipid layers with phospholipids
Cholesterol converted to
Primary bile in liver, various hormones, 7-dehydrocholestrol in skin from the sunlight
Cholesterol as fuel
Cannot be used as fuel since it cannot be catabolized by most cells
Esterified form of cholesterol
Cholesteryl ester in which the OH group is conjugated by an ester bond to a fatty acid
Lipoproteins structure
Consist of lipids and proteins with amphipathic cholesterol and phospholipid on surface, hydrophobic, neutral triglyceride and cholesteryl ester in core
Chylomicron
Largest in size, lowest in density due to high lipid to protein ratio, highest amount of triacyclglycerols, cause turbidity of postprandial plasma, on top of stored plasma forming creamy layer, deliver dietary lipids to hepatic and peripheral cells
VLDL
very low density lipoprotein, 2nd highest in triacyclglycerols, major carriers of endogenous triglycerides and transport triglycerides from liver to peripheral tissues, cause most turbidity in plasma, no creamy layer
IDL
intermediate density lipoprotein
LDL
low density lipoprotein, highest in cholesteryl esters, can infiltrate extracellular space, oxidized and taken up by macrophages
HDL
high density lipoprotein due to high protein to lipid ratio
Apolipoproteins
Located on surface of lipoproteins, serve as ligands for cell receptors and as activators/inhibitors of different enzymes that regulate lipoprotein particles
Apolipoprotein A-1
Major protein on HDL
Apolipoprotein B
Principle protein on LDL, VLDL and chylomicrons
Apo B-100
Found on LDL and VLDL, a ligand for the LDL receptor and linked to lipoprotein (a)