Mod 3 Flashcards
Lipids importance
Contribute to food structure
Burned for energy
Energy reserve (stored)
Structurally diverse
Fatty acids
Base lipid unit
4-24 C
Processed in 2C units
Omega end
Ch3 end
Alpha end
Carbox acid end
Saturated fats
Stearic acid
Animal fats
Monounsaturated fat
Oleic acid
Olive and canola oils
Polyunsaturated fat
Linoleic acid
Sunflower, safflower, corn, soybean oils
Linolenic acid
Soybean, canola oils, flaxseed, walnuts
Essential fatty acids
Cells lack enzymatic machinery to place double bonds between w end and C9
Must get w6 and w3 from the diet
Essential fatty acids purpose
Cell membranes
Immune function
Vision
Complex lipid structure
Eicosanoid production
Linoleic acid
Used to make series 1 and 2 eicosanoids
Stimulates blood clotting
Too much → heart attack/heart disease
Alpha-linolenic acid
Used to make series 3 eicosanoids
Lead to decreased blood clotting
Reduce synthesis of group 2 eicosanoids
Too much → hemorrhagic stroke
Rancidification
Auto Oxidation or hydrolysis of fats/oils
Produce short chain aldehydes, ketones, FA
Oxidation occurs with unsaturation
Hydrogenation
Add hydrogens across double bond
Protect against rancidity
Passing cell membranes
Free FA, monoglycerides, and glycerol can
TG must be hydrolyzed by lipases first
Triglycerides purpose
Provide energy
Energy storage
Insulation/protection (organs)
Transport of fat-soluble vitamins
Phospholipids
Contain 2 fatty acid chains
Third position is a phosphate linked group
Component of cell membranes
Emulsifiers
Phospholipids organize in aq solution
Head oriented towards water
Interior =hydrophobic core
Composition of lipoproteins
Phospholipid outer shell
Triglyceride interior
Includes cholesterol and protein
Chylomicrons
Transport diet derived lipids
Small intestine → lymphatic → blood
VLDL
Created in liver
From dietary and newly synthesized lipids
Carry lipids and cholesterol to tissues
LDL
Derived from VLDL
Mostly cholesterol
Internalized by a receptor pathway in liver/tissues
Supplies cholesterol for growth/tissue development
HDL
Synthesized in liver and intestine
Pick up cholesterol from dying cells
Lipoprotein Lipase
Enzyme attached to blood vessels
Hydrolyze TG → glycerol + 3 FA
Deliver lipids to surrounding tissue
Sterols
From cholesterol
From animal sources
Precursor to steroid hormones + fat soluble vitamins
Fed state
Clearing of blood lipids
Lipids delivered to muscle and adipose
Fasting state
Hormone sensitive lipase activated in adipose by glucagon
TG breakdown and mobilization of glycerol + FFA
Emulsifier Ex
Lecithin
Polysorbate 60
Phosphatidylcholine
(Phospholipids)
Egg Yolk
Monoacylglycerol
