lipid chemistry

Question 1

what are lipids

Answer 1

organic compounds formed mainly from alcohol and fatty acids by ester linkage

Question 2

solubility of lipids

Answer 2

insoluble in water and soluble in fat and organic solvents

Question 3

what are the biological importance of lipids

Answer 3

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)

Question 4

what are lipoproteins

Answer 4

transport form of energy and enter the structure of cell membrane

Question 5

name the lipid that enter the structure of cell membrane and used for synthesis of
hormones, vit D3 and bile acids

Answer 5

cholesterol

Question 6

stored lipids or depot fat in cell act as

Answer 6

store of energy
pad for the internal organs to protect them
subcutaneous thermal insulator
components of ETS

Question 7

what are the classification of lipids based on chemical nature

Answer 7

simple lipid-triglycerides (fat & oil), wax
complex lipid-phospholipid, glycolipids,
lipoproteins
derived lipid- fatty acids, alcohols
lipid associated substance- steroids,
carotenoids, fat, soluble vitamins

Question 8

what are simple lipids

Answer 8

they are esters of fatty acids with various alcohols

Question 9

simple lipids are subclassified as

Answer 9

neutral fats or oils ; alcohol is glycerol
waxes ; alcohol other than glecerol

Question 10

name the grp of fatty acid that are the ester of glycerol with various FA

Answer 10

neutral fat or oils

Question 11

since the 3 hydroxyl groups of glycerol are esterified the neutral fats are also called

Answer 11

triglycerides

Question 12

what are the types of triglycerides

Answer 12

1. simple triglyceride
2. mixed triglyceride

Question 13

if three fatty acids connected to glycerol are of the same type is called _________ triglyceride give one example

Answer 13

simple triglyceride
tripalmitin

Question 14

if different types of FAs are connected to glycerol are ______________ triglyceride
give example

Answer 14

mixed triglyceride
stearodiolein

Question 15

________ fats are mixture of mixed triglycerides with a small amt of simple triglyceroid

Answer 15

natural fats

Question 16

physical properties of triglycerides

Answer 16

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

Question 17

what is the main difference between fats and oils, why

Answer 17

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

Question 18

esters of long-chain FAs with a monohydric alcohol with a higher mol wt than glycerol is called

Answer 18

waxes

Question 19

what are the properties of wax

Answer 19

insoluble in water, soluble in fat solvent
not easily hydrolyzed and are indigested by lipase
no nutritional value

Question 20

lipids that contain additional substance eg: S, P, amino grp, carbohydrate or proteins beside FA and alcohol are called

Answer 20

compound/ complex/ conjugated lipids

Question 21

compound lipids are classified into

Answer 21

phospholipids= FA+ OH+ Phosphate + NB
glycolipids= FA+ OH+ carbohydrate
lipoproteins= lipid+ protein
sulpfolipids and amino lipids

Question 22

what is glycerophospholipids and sphingophospholipids

Answer 22

glycerophospholipids= alcohol is glycerol
sphingophospholipids= alcohol is sphingosine

Question 23

what are FAs

Answer 23

1. aliphatic monocarboxylic acids mostly obtained from hydrolysis of natural fats and oils
2. carboxylic acids with hydrocarbon side chain

Question 24

FAs are classified according to presence or absence of double bond

Answer 24

saturated FAs
unsaturated FAs

Question 25

what are the features of saturated FAs

Answer 25

no double bond 2-24 or more carbon
solid at room temp except if they are short chained
may be even or odd numbered

Question 26

unsaturated FAs are dived into _________ and _______ on based on

Answer 26

1. monosaturated: 1 double bond
   2.polyunsaturated: more than 1 double bond

Question 27

classification of FAs based on total no of carbon atoms

Answer 27

even chain : common
odd chain: microbial cell wall and milk

Question 28

classification of FAs bard on length of hydrocarbon chain

Answer 28

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

Question 29

name a typical saturated FA with 18 c in the chain

Answer 29

steric acid

Question 30

name a typical unsaturated FA with 18 c atoms

Answer 30

oleic acid

Question 31

H’s on same side of the double bond ; fold into U-like formation is called

Answer 31

Cis- FA
naturally occuring

Question 32

H;s on opposite side of double bond

Answer 32

trans-FA
occur in partially hydrogenated foods

Question 33

what are the types of nomenclature of FAs

Answer 33

delta, omega

Question 34

PUFA are identified by position of the nearest double bond to methyl end of the carbon chain is

Answer 34

omaga numbering

Question 35

why the FAs with double bond before 9 th c are essential FAs

Answer 35

your body cannot form C=C before the 9th C and can form after 9th C

Question 36

give an example of omega 3 and omega 6 FA

Answer 36

omega 3- linolenic acid
omega 6-linoleic acid

Question 37

the chain length and the number and position of double bonds from carboxylic bond is

Answer 37

delta nomenclature

Question 38

which type of FA is correlated with a decreased risk of cardiovascular disease

Answer 38

omega-3 FAs

Question 39

high omega 3 FAs have also been associated with

Answer 39

a decrease in serum triglycerides

Question 40

omega 3 FAs are high in

Answer 40

some cold water fish -salmon, tuna, herring
nuts- walnuts
seeds-flaxseed

Question 41

double bond in ____________ FAs are cis-configuration

Answer 41

natural FAs