Lipids Flashcards
are organic substances, relatively insoluble in water and soluble in organic solvents like alcohol, ether, etc. They are mainly compounds of C, H and O, but also carry P, N and S in some cases
Lipids
Functions of lipids
Source or storage of energy
Concentrated energy reserve (Adipose tissue)
Constituent of and regulate membrane permeability
Metabolic regulator
insulating materials against low temp
Source of fat-soluble vitamins and bile acids
Phospholipids, glycolipids and sterols are constituents of plasma lipoprotein, which transport fat
monocarboxylic acids with hydrocarbon side chain. They are the simplest form of lipids.
fatty acids
Do not contain double bonds in their hydrocarbon chain, e.g., palmitic and stearic aci
saturated FA
Contain one (monounsaturated aka MUFA) or more (polyunsaturated aka PUFA) double bonds in their hydrocarbon chain, e.g., oleic acid, linoleic acid, linolenic acid, arachidonic acid
Unsaturated FA
Common FA and their no. of carbons
lauric acid 12:0
myristic 14 :0
palmitic 16 :0
stearic 18 :0
palmitoleic 16:1
Oleic 18:1
linoleic 18:2
Linolenic 18:3
arachidonic 20:4
Not synthesized in the body, therefore should be taken in the diet,
essential FA
examples of essential FA
omega -6 FA
Linoleic acid
Arachidonic acid
omega-3 FA
Linolenic acid
Eicosapentanoic acid
Docohexaenoic acid
These FA can be synthesized in the body
non-essential FA
examples of non-essential FA
stearic
palmitic
TRUE or FALSE
Saturated fatty acids are usually solids at room temperature.
TRUE
TRUE or FALSE
Most unsaturated fats are liquid oils at room temperature.
TRUE
TRUE or FALSE
The longer the fatty acid chain, the higher the melting point of the fatty acids.
TRUE
TRUE or FALSE
Unsaturated FA has a higher melting point than saturated FA
FALSE
Unsaturated fatty acids have lower melting point than saturated fatty acids (degree of unsaturation).
aka fats, are esters of 3 fatty acids with 1 glycerol combined through esterification process; form of fatty acids for transport between tissues, storage of metabolic fuel, and storage as oils in seeds that provide energy for seed germination
TAGs
hydrogen gas is bubbled through the heated oil typically in the presence of a nickel catalyst resulting in H atoms added to one or more carbon-carbon double bonds to form carbon-carbon single bonds.
hydrogenation
Hydrolysis (split by water) in the presence of strong acids such as HCl or sulfuric acid or digestive enzymes called
lipases
occurs when a fat is heated with a strong base such as NaOH to form glycerol and the sodium salts of the fatty acids, which is soap.
saponification
esters of fatty acids with long-chain aliphatic alcohols each containing from 14 to 30 carbon atoms.
Waxes
It is used in candles, shoe polish, and wax paper
Beeswax
It is used as waxes for furniture, cars, floors, and shoes
Carnauba wax
It is used in candles, soaps, and cosmetics
Jojoba wax
esters of fatty acids with alcohol, carrying additional groups such as phosphate and nitrogenous group or carbohydrate
compound lipids
two fatty acids form ester bonds with the first and second hydroxyl groups of glycerol. The third hydroxyl group forms an ester with phosphoric acid, which forms another phosphoester bond with an amino alcohol.
glycerophospholipid
are two types of glycerophospholipids that are particularly abundant in brain and nerve tissues as well as in egg yolks, wheat germ, and yeast.
Lecithin and cephalin
- Membrane component, nerve transmission
- Source of choline and methyl group
Lecithin
- Lung surfactant
- Deficiency causes respiratory distress syndrome
Dipalmitoyl lecithin
Structural component of membranes
cephalin
- Structural component of membranes in brain and muscle
plasmalogens
- Mediator of hypersensitivity, acute inflammatory reactions and anaphylactic shock
platelet-activating factor
Component of inner mitochondrial membrane has antigenic properties
cardiolipin
- Phosphatidylinositol 4,5-biphosphate is second messenger for hormone action
- Anchors the glycoproteins to membranes
phosphotidylinositol
present in plasma membranes of animal cells and prominent in myelin. Sphingosine molecule replaces glycerol. Sphingosine is a long-chain amino alcohol.
sphingolipids
structural parent of all sphingolipids
ceramide
contain phosphocholine or phosphoethanolamine as their polar head group. These are major component of membranes of nervous tissue
sphingomyelin