Lipids Flashcards
- Solid at room temperature.
- Animal sources
- Except coconut and palm oils which are solid at room temperature.
Fats
- Liquid at room temperature.
- Plant sources
- Except fish oils which is liquid at room temperature.
Oils
- Also composed of C, H, and O atoms like carbs but differs in proportion.
- Insoluble to water but soluble in organic solvents.
Composition of Lipids
• Edible lipids:
triglycerides, phospholipids, and sterols.
• Triglyceride =
1 glycerol + 3 fatty acids
Lipids are stored in
Adipose tissue
Structural function
◦Insulation,
protection,
integral parts of cells & tissues
Lipids spare ___, ___, and ___.
Spare protein, B1 & B3
Simple Lipids or Neutral fats
Trigylcerides and fatty acids
Compound Lipids
Phospholipids
Components of Phospholipids
Neutral fats +
Phosphoric acid +
Nitrogenous base
Sources of Phospholipids
eggs, soy beans, liver, wheat germs, peanuts
•Cell membranes, emulsifiers
Derived lipids
Sterol
type of lipids that is obtained by hydrolysis or enzymatic breakdown
Derived Lipids
no double bonds FA
Saturated FA
one double bond FA
Monounsaturated FA
two or more double bonds FA
Polyunsaturated
Degree of unsaturation affects the
temperature at which the molecule
melts. If saturated the molecules are ___.
firm
Degree of unsaturation affects the
temperature at which the molecule
melts. If unsaturated the molecules are ___.
more liquid
All electrons in outermost valence of C are paired in this type of fatty acid.
Saturated FA
Sources of Saturated Fatty Acid
coconut oil, chocolate, butter, animal fat
Sources of Monounsaturated FA (MUFA)
•Oleic acid in olive oil, avocado, almonds
Sources of Polyunsaturated FA (PUFA)
•Linoleic acid in corn oil, soy bean oil, fish oils
Oxidation of Unsaturated Lipids may result to ___ ___ & ____.
rancid odor & taste
rancid odor & taste can be minimized by
HYDROGENATION
type of food products that can cause an increase in LDL cholesterol and decrease in HDL cholesterol -> which increases the risk of heart disease
Processed foods
contains 6 C or less carbon atoms
Short-chain FA
examples of Short-chain FA
Butyric acid, Caproic Acid
6–12 carbon atoms
Medium-chain FA
examples of Medium-chain FA
Stearic acid, Lauric
> 12 carbon atoms
Long chain FA
examples of Long chain FA
Palmitic, EPA, DHA
- Omega 6 FA
- Derivative of Arachidonic FA
- Promotes arterial dilatation and contractility of the heart
Linoleic FA
- Omega 3 FA
- Derivative of eicosanoids like EPA and DHA
- Promotes growth and development
- Modulates clotting and blood pressure
Linolenic FA
enzyme that breaks down Triglyceride into Glycerol + 3FA
Pancreatic Lipase
an enzyme that attaches free cholesterol to fatty acid for the absorption of cholesterol
Cholesterol esterase
Breaks down lecithin
Lecithinase
Transport vehicles for lipids in the lymph or blood
LIPOPROTEINS
Made up of Triglycerides
- largest, least dense, carry greatest number of TGs
- carry TGs from intestine to the rest of the body
- grows smaller in size as lipids are carried to other cells
- protein remnants of LPs get dismantled in liver for recycling Transports lipids from the intestine to the liver
Chylomicron
- Made up of Triglyceride
- Formed in the liver
-LPs synthesized in the liver for delivery to other body cells of TGs - “drops off” TGs at different sites
-After losing TGs, VLDL picks up cholesterol circulating in the bloodstream
VLDL - > LDL
Very Low- Density Lipoprotein
- LPs with low pro to lipid ratio
- provide cholesterol and few TGs to cells in muscles, the heart, fat stores, mammary glands, etc.
- Made out of cholesterol
Low Density Lipoprotein (LDL)
- LPs with high pro to lipid ratio
- synthesized in the liver
- carry cholesterol and PLs from cells back to the liver for breakdown or disposal
- Made out of proteins
High Density Lipoprotein (HDL)
Intermediate between VLDL and LDL
Intermediate density lipoprotein
Arrange in descending order according to density: ◦LDL ◦Chylomicrons ◦HDL ◦VLDL
Descending order according to density.
- HDL: half protein, accounting for high density
- LDL: half cholesterol, accounting for implication in heart disease
- VLDL: half TG, accounting for low density
- Chylomicrons: so little protein and so much TG that they are the lowest in density
• Carry cholesterol to the
cells for utilization
VLDL, IDL, and LDL
• Carries cholesterol from the cells to the liver for breakdown and elimination from the body
HDL
Helps protect against heart disease
Increased values are better
Good Cholesterol (HDL)
Increases risk of heart disease
Reduced values are better
Diets high in saturated fat and trans fatty acids raise LDL levels
Bad Cholesterol (LDL/VLDL)
Normal Blood Values of HDL
HDL= 40 mg/dL or higher
Normal Blood Values of LDL
LDL= <130 mg/dL
obesity is more directly linked to
total fat
cancer is more directly linked to
unsaturated
CVD cardiovascular disease is more directly linked to
saturated
Percent Recommended intake of energy from fat
20 -30%
Percent Recommended intake from PUFA
10% of TER
Percent Recommended intake from MUFA
10-15% of TER
Rest or less than __% from saturated fatty acids (SFA)
7-10% of TER
__ - ___% of TER for preschool to elderly
20-30%
Percent Recommended intake of lipids for Infants
30-40%