Lipids Part 1 Flashcards
Lipids
• 4 main groups
(Saturated and Unsaturated)
(Glycerol-containing Lipids)
(Sphingolipids,Steroids,Wax)
(Lipoproteins)
– Fatty Acids
– Glycerides
– Nonglyceride Lipids
– Complex Lipids
Energy Source
– When oxidized, each gram of fat releases______ of energy, or more than twice the energy released by oxidation of a gram of carbohydrate
9 kcal
Energy Storage
– In the form of ____in adipocytes
triglycerides (TAG)
Cell Membrane Structural Components
(3) make up the basic structure of all cell membranes
– Phosphoglycerides, sphingolipids, and steroids
BIOLOGICAL FUNCTIONS OF LIPIDS
• Hormones –_____ Hormones
• Vitamins – Lipid-soluble vitamins
• Vitamin Absorption – Dietary fat serves as a____ of the lipid-soluble vitamins
• Protection – fats as
• Insulation – subcutaneous fat
Steroid
(A,D,E, and K)
carrier
shock absorber
• Are long-chain monocarboxylic acids
• Generally contain an even number of carbon atoms
FATTY ACIDS
FATTY ACIDS
• Short-Chain Fatty Acids
• Medium-Chain Fatty Acids
• Long-Chain Fatty Acids
– Less than 6 carbons
– 6-10 carbons
– More than 12 carbons
– Each C being “saturated” with H
Saturated Fatty Acids
Sat. Fatty Acids
– General Formula:
CH3 (CH2 )nCOOH
– Composed of at least one carbon-to carbon double bond
– Almost are in the cis configuration
Unsaturated Fatty Acids
– Composed of one carbon-to-carbon double bond
Monounsaturated Fatty Acids (MUFA)
– Composed of more than one carbon-to carbon double bond
Polyunsaturated Fatty Acids (PUFA)
– are identified by position of the double bond nearest the methyl end (CH3 ) of the carbon chain; this is described as an omega number;
Polyunsaturated Fatty Acids (PUFA)
– If PUFA has first double bond 3 carbons away from the methyl end =
omega 3 FA
- If PUFA has 6 carbons from methyl end =
omega 6 FA
– H’s on same side of the double bond; fold into a U-like formation; naturally occurring
cis-Fatty Acid
– H’s on the opposite side of the double bond; occur in partially hydrogenated food
trans-Fatty Acid
Fatty acids with double bonds before
the 9th carbon are
ESSENTIAL
Fatty acids with no double bonds before the 9th carbon are
NONESSENTIAL
Your body can form C=C double bonds after the 9th carbon
Nonessential
– Fatty acids react with alcohols to form esters and water
Esterification