lipid chemistry Flashcards
what are lipids
organic compounds formed mainly from alcohol and fatty acids by ester linkage
solubility of lipids
insoluble in water and soluble in fat and organic solvents
what are the biological importance of lipids
most diet palatable
source of high energy
source of essential fatty acids
constituent of nervous system
source of fat soluble vitamins (A, D, E& K)
what are lipoproteins
transport form of energy and enter the structure of cell membrane
name the lipid that enter the structure of cell membrane and used for synthesis of
hormones, vit D3 and bile acids
cholesterol
stored lipids or depot fat in cell act as
store of energy
pad for the internal organs to protect them
subcutaneous thermal insulator
components of ETS
what are the classification of lipids based on chemical nature
simple lipid-triglycerides (fat & oil), wax
complex lipid-phospholipid, glycolipids,
lipoproteins
derived lipid- fatty acids, alcohols
lipid associated substance- steroids,
carotenoids, fat, soluble vitamins
what are simple lipids
they are esters of fatty acids with various alcohols
simple lipids are subclassified as
neutral fats or oils ; alcohol is glycerol
waxes ; alcohol other than glecerol
name the grp of fatty acid that are the ester of glycerol with various FA
neutral fat or oils
since the 3 hydroxyl groups of glycerol are esterified the neutral fats are also called
triglycerides
what are the types of triglycerides
- simple triglyceride
- mixed triglyceride
if three fatty acids connected to glycerol are of the same type is called _________ triglyceride give one example
simple triglyceride
tripalmitin
if different types of FAs are connected to glycerol are ______________ triglyceride
give example
mixed triglyceride
stearodiolein
________ fats are mixture of mixed triglycerides with a small amt of simple triglyceroid
natural fats
physical properties of triglycerides
freshly prepares are color less and odorless
yellow color of body fat or milk fat is de to carotene pigments
specific gravity <1 so floats on water
insoluble in water and soluble in organic solvents as ether and benzene
what is the main difference between fats and oils, why
oils being liquid and fats are solid in room temp
due to presence of large amt of unsaturated FA in oil and mostly unsaturated FA in fats
esters of long-chain FAs with a monohydric alcohol with a higher mol wt than glycerol is called
waxes
what are the properties of wax
insoluble in water, soluble in fat solvent
not easily hydrolyzed and are indigested by lipase
no nutritional value
lipids that contain additional substance eg: S, P, amino grp, carbohydrate or proteins beside FA and alcohol are called
compound/ complex/ conjugated lipids
compound lipids are classified into
phospholipids= FA+ OH+ Phosphate + NB
glycolipids= FA+ OH+ carbohydrate
lipoproteins= lipid+ protein
sulpfolipids and amino lipids
what is glycerophospholipids and sphingophospholipids
glycerophospholipids= alcohol is glycerol
sphingophospholipids= alcohol is sphingosine
what are FAs
- aliphatic monocarboxylic acids mostly obtained from hydrolysis of natural fats and oils
- carboxylic acids with hydrocarbon side chain
FAs are classified according to presence or absence of double bond
saturated FAs
unsaturated FAs
what are the features of saturated FAs
no double bond 2-24 or more carbon
solid at room temp except if they are short chained
may be even or odd numbered
unsaturated FAs are dived into _________ and _______ on based on
- monosaturated: 1 double bond
2.polyunsaturated: more than 1 double bond
classification of FAs based on total no of carbon atoms
even chain : common
odd chain: microbial cell wall and milk
classification of FAs bard on length of hydrocarbon chain
short chain FAs: 2-6 c atoms
medium chain FAs: 8-14 c atoms
long chain FAs: 16-22 c atoms
very long chain FAs: >24 c atoms
name a typical saturated FA with 18 c in the chain
steric acid
name a typical unsaturated FA with 18 c atoms
oleic acid
H’s on same side of the double bond ; fold into U-like formation is called
Cis- FA
naturally occuring
H;s on opposite side of double bond
trans-FA
occur in partially hydrogenated foods
what are the types of nomenclature of FAs
delta, omega
PUFA are identified by position of the nearest double bond to methyl end of the carbon chain is
omaga numbering
why the FAs with double bond before 9 th c are essential FAs
your body cannot form C=C before the 9th C and can form after 9th C
give an example of omega 3 and omega 6 FA
omega 3- linolenic acid
omega 6-linoleic acid
the chain length and the number and position of double bonds from carboxylic bond is
delta nomenclature
which type of FA is correlated with a decreased risk of cardiovascular disease
omega-3 FAs
high omega 3 FAs have also been associated with
a decrease in serum triglycerides
omega 3 FAs are high in
some cold water fish -salmon, tuna, herring
nuts- walnuts
seeds-flaxseed
double bond in ____________ FAs are cis-configuration
natural FAs
