chemistry of carbohydrates:-monosaccharides, Disaccharides , polysaccharides and its clinical importance

1. CHEMISTRY OF
CARBOHYDRATE
DR. JASWANT KAUR
ASSISTANT PROFESSR

2.  At the end of this chapter student should be
able to:
 Define carbohydrates and its biomedical
importance.
 Classify carbohydrates with examples .
 Explain the different types of isomerism seem
in them.
 Enumerate the properties and reactions of
monosaccharides .
 Explain glycosides formation.

3.  Important carbohydrates and their derivatives .
 Describe how various monosaccharides form
diasaccharides and polysaccharides , also
discuss their functions .
 Explain the main function of carbohydrate in
the body and their use in clinical medicine
 Give examples of dietary , structural , storage
polysaccharide and explain their function in
body .

4.  Define glycemic index of
carbohydrate and explain its
significance .

5.  Carbohydrate is also known as saccharides.
 Chemically , contain elements i.e Carbon,
hydrogen & oxygen.
 (CH₂O)n
 Carbohydrate also contain nitrogen,
phosphorus.

6.  Definition:- aldehyde or ketone derivatives of
Polyhydroxy alcohols or as compounds that
yields these derivatives on hydrolysis.
 Functions :-chief source of energy for living.
 Storage form of energy eg;- glycogen in
animals , Starch in plants.
 Starch and sucrose are major dietary
components , it meet 60-70% of our energy
requirement.
 Brain cells and RBCs are almost wholly
dependent on carbohydrates for energy.

7.  Carbohydrates constituents of glycoprotein
& proteoglyans .
 present
cells , tissues and organs
 Examples
several enzymes, hormones, plasma proteins, cell
surface molecule acting as receptors are all
glycoproteins.
 Blood group substances are carbohydrate in
nature.
 Carbohydrates are used to synthesize many
compounds like fats , amino acid etc.

8.  Energy production from carbohydrates will be
4 kcal / g.
 Also involved in detoxication.
 Constituents of nucleotides that form
RNA & DNA eg:-ribose , deoxyribose
sugar.
 Abnormality of carbohydrate metabolism
leads various diseases like DIABETES
MELLITUS, galactosemia etc.

9. Q1. Main source of energy in the body
a.
Q2. RBCs and brain cells are dependent on which
energy source:-
a. fat b. vitamins c. proteins d. carbohydrates
Q3. Storage form of energy
a. starch b. Glycogen c. glucose d. fructose

10.  Broadly divided into three parts:-
 Monosacchrides
 Oligosacchrides
 Polysacchrides
 Monosacchrides:- single polyhydroxy
aldehyde or ketone units which cannot be
hydrolyzed into simpler form.
 Example :- Glucose

11.  Oligosaccharides:- consists of a short chain
of monosaccharides units joined together by
glycosidic bonds which on hydrolysis gives
two to ten molecules of monosaccharides.
 Disaccharides:-made up of two
monosaccharides units .
 Example :- Maltose , Lactose ,sucrose
 Polysaccharides:- consists of hundreds or
thousands of monosaccharides units. also k/a
glycans or complex carbohydrates.
 Example :- starch , cellulose

12.  Depends upon no. of carbon atoms they are: -
-Trioses (CH2O)n
-Tetroses
-Pentoses
-Hexoses
 Depends upon functional groups.
- Aldehyde groups- Aldoses
- Ketone groups-Ketoses

13. • - according to ketone groups.
No. of c- atoms Type of sugar Aldoses ketoses
3 (C₃H₂O₃) Trioses glyceraldehyde dihydroxyaceton
e
4 ( C₄ H₈O₄) Tetroses erythrose erythrulose
5 (C₅ H₁ₒO₅) Pentoses ribose ribulose
6 (C₆H₁₂O₆) Hexoses glucose fructose
7 (C₇H₁₄O₇) Heptoses glucoheptoses sedoheptulose

14.  Glucose is the most important monosacch-
arides. The structure of glucose are 3 types:-
-Fisher projection( straight chain).
-Cyclic form.
-Boat & chair form
 Alydehyde gp. Of C-1 reacts with –OH gp. at
C-5 or C-4 to form either six membered ring
is called pyranose or five membered ring is
furanose

16. • ISOMERISM:- identical molecular formula
but different structure is known as
isomers. the phenomenon of existence of
isomers is as isomerism.
• Structural isomerism:- same molecular
formula but differ in structure . Eg:-
glucose & fructose
• Stereoisomerism:- same molecular
formula , same str. But differ in
configuration .eg:- D-glucose & L-
glucose.

17. B
A C D
E
 Asymmetric carbon :- carbon atom attached
to the four diff. groups

18. D-isomers & L-isomer:-mirror images are each
other.
 Spatial orientation of – H & - OH groups on carbon
atom( C₅ for glucose) that is adjacent to the
terminal primary alcohol carbon, determine the
sugar is D & L-isomer.
 - OH gp.lie on rt. side is known as D-sugar.
 If on left side it is L-sugar.
 Enantiomers:- One member of the pair is called
enantiomers. It gives mirror image of each other.
eg:-D & L glucose

19. 
 mirror

20.  Steroisomerism
 D and L isomerism
 Optical isomerism
 Epimers
 Anomers
 Structure of monosaccharides
 Reactions of monosaccharides
 Mutarotation
 Benedicts reaction
 Osazone formation

21.  D & L series :-The orientation of the − H
and − OH groups around the carbon atom
adjacent to the terminal primary alcohol carbon
(carbon 5 in glucose) determines whether the
sugar belongs to the D or L series.
 Dextrorotatory (+) & levorotatory (−) sugar:-
 Dextrorotatory (+); or levorotatory (−) denote the
nature of the optical activity. When plane
polarized light is rotated to the rt. Sugar is
designated D(−), D(+) dextrorotatory
 Rotated left then sugar is L(−), or L(+)
levorotatory .
Eg:- naturally occurring form of fructose is the
D(−) isomer.

22. D & L-series of glyceraldehydes:-
H-C=O H-C=O
H-C-OH HO-C-H
CH₂OH CH₂ OH

23.  The presence of asymmetric carbon atoms
also confers optical activity on the
compound. When a beam of plane-polarized
light is passed through a sugar solution
exhibiting optical activity. It will be rotated to
the rt. Or left acc. to the type of compound,
are k/a optical isomer

24.  Epimers:- when sugars are different from one
another, only in configuration with regard to a
single carbon atom, other than the reference
carbon, are called epimers. Eg:- glucose &
galactose ( C-4), glucose & mannose (C-2).
 Epimerization:- process by which one epimer is
converted to other .
 It requires the enzyme i.e epimerase,
galactose glucose
(liver)

26.  α &ß forms of glucose:- aldhyde gp. Of C-1,
on cyclization ,condenses with alcoholic gp
on C-5 on the same molecule, two diff. cyclic
forms are produced.
 OH gp at c-1 extend rt. is K/a α- D-glucose
 On left side is K/a ß-D-glucose.
 Anomers:- after cyclization , two cyclic
compounds α &ß have different optical
rotation but they are not mirror image of
each other. C-1 is k/a anomeric carbon .

29.  Mutarotation:- change in the specific optical
rotation by the interconversion of α& ß forms
of D-glucose to equilibrium mixture.
 -in water α-D glucopyranose & ß-D
glucopyranose is first dissolved & then the
solution is put in the optical path so that the
plane polarized light is passed, the initial
optical rotation changes until a constant fixed
rotation is reached. This change of rotation is
K/a the Mutarotation

30.  when crystalline sample of either anomers is
dissolved in water , its specific rotation of
polarized light is+112; its changes with time
until an equilibrium value of +52.7 is
attained.
 Non reducing sugar cannot show
mutarotation due to the absence of free
anomeric OH gp.
α -D-glucose equilibrium ß -
D-glucose
(+112) mixture of glucose (+19)
(+52.7)

32. Mutarotation: Spontaneous conversion of one anomer to the other
Equilibrium: 36% α-anomer, 63% β-anomer, <1% open-chain form
O
H OH
OH H
CH2OH
H
OH
H H
OH
O
H OH
OH H
CH2OH
H
OH
H OH
H
CHO
Ι
H – C – OH
Ι
HO – C – H
Ι
H – C – OH
Ι
H – C – OH
Ι
CH2OH
D-Glucose
α-anomer
β-anomer

33. - Action of strong acid:- basis of Molish test,
seliwanoff’s test.
- Action of alkalis:-basis of benedicts &
fehling’s test.
D-glucose 1,2- enediol D-
fructose
D-mannose

34. - oxidation:- sugar acids formation.eg:-
D-glucose glucuronic acid
- Reduction:- Carbohydrate with a free aldehyde or
ketone group
- .eg:-

35. Action of phenylhydrazine:- osazones are
crystalline derivatives of sugars. They have
features :-
melting pt. , crystal str. & precipitation
times.
- Glucose & fructose:- Hay like
- Maltose:- sunflower
- Lactose:- Powder puff
- Galactose :- sunflower like but narrow
blades.

37.  Glycosides:- OH gp. Of the anomeric carbon of a
monosaccharides reacts with an OH or an NH
gp.of another compound formed glycosides.
 Non carbohydrate gp. Is called aglycon.
 Glycosides are found in many drugs, Like Cardiac
glycosides- act as cardiac stimulant.
 Bonds joined the monosaccharides are called
glycosidic bonds. These are two types:-
 O-glycosidic bonds
 N-glycosidic bond

40.  Digitalis is a glycosides .
 Used in heart failure .
 Complex str. In which three sugars joined
with a steroid.
 Increase the contraction of heart muscles
without increasing the heart rate.
Strepotomycin :- glycosides
- Used as antibiotic.
- Contain amino sugar.

41. Amino sugar:- OH gp. replaced by an amino gp.
Eg. Glucosamine, N-acetyl glucosamine,
galactosamine.
Role:-1).Amino sugar are component of
glycolipid , glycoprotein & glycosaminoglycans .
2). Role in antibiotics like erythromycin,
carbomycin.
3). N-acetyl glucosamine occurs as constituent
of MPS such as hyaluronic acid, heparin.

43. Deoxy sugar:- removal of oxygen from –OH gp.
Of sugar. It possess H-atom in place of OH gp.
Function:- 2- deoxy ribose found in nucleic acid
DNA.
- L-fucose ( deoxy sugar) found in glycoprotein.
- Deoxy sugar will not reduce .
- It will not form osazones crystals.
- 6- deoxy L- galactose is found as a
constituents of glycoproteins , blood group
substances.

45.  Sugar alcohol :- produced by reduction of
aldoses & ketoses. Eg:- sorbitol from
glucose.
 Pentoses:- sugar containing 5-C atoms.
 Sugar acid:- Oxidation of aldehyde or primary
alcohol gp. in monosaccharides. Eg:-
Gluconic acid , glucuronic acid .
 L-ascorbic acid:- water soluble vitamin , str.
Resembles that of monosaccharides.

46.  Sorbitol and mannitol
 Excess Glucose sorbitol
 ( Diabetes mellitus )
 cataract ( eyes)
 microangiopathy
 neuropathy , nephropathy

47. 
 Has high osmotic pressure
 Used as a intravenous infusion medicine
 To decrease intracranial pressure ( inside the
skull due to swelling or accumulation of
blood) .

48.  Oligosaccharides:- consists of a short chain of
monosaccharides units joined together by
glycosidic bonds which on hydrolysis gives two to
ten molecules of monosaccharides.
 Disaccharides:-made up of two monosaccharides
units . These are reducing & non reducing. Its
types:-
 Maltose:- glucose + glucose
 Lactose:- glucose + galactose
 Sucrose:- glucose+ fructose

49. Maltose:- made up of two molecule of glucose.
- Known as malt sugar .
- held together by α (1 4) linkage.
- reducing in nature( free aldehyde gp. at C-1)
- sweet sugar, soluble in water.
- gives sunflower like osazones crystals.
- on hydrolysis it gives two molecules of
glucose by maltase enzyme.
- Produced during digestion of starch by amylase.

51.  Isomaltose:- reducing sugar
- α (1-6) linkage.
- on partial hydrolysis of starch & glycogen
produces isomaltose ,which hydrolyze into
glucose units.

52. Lactose:- made up of glucose & galactose.
-known as milk sugar.
- joined by ß (1 -4 ) glycosidic bond
- reducing sugar.
- powder puff osazones crystal formed.
- dextrorotatory , not very soluble, not so
sweet,
- On hydrolysis , it gives glucose+
galactose by lactase enzyme.

54. Sucrose:- made up glucose & fructose.
- known as table sugar or cane sugar.
- non – reducing sugar.
- Can not form osazone
- Bonding is form by α (1-2) ß linkage.
- is also known as invert sugar.
- On hydrolysis , it gives αD- glucose + ß-D
fructose by sucrase enzyme.
- Benedicts test give negative

56.  Invertion :- process of change of optical rotation
from dextrotatory to levorotatory is known as
invertion.
 Invert sugar:- sucrose is dextrotatory , but on
hydrolysis it becomes levorotatory. Because
fructose has greater specific levorotation than
dextrotation of glucose.

57. Invert Sugar
Sucrose (
dextrorotatory)
(+66.5ͦ ) on hydroysis
Glucose fructose
(dexto.) (levo.)
(+52.5) (-92)
sucrose
invert sugar (levo.)

58.  Maltose:- used in baby food
preparations , easily digested ,
nutritional significance
 hydrolyzed in small intestine by
maltase, give two molecules of
glucose , are absorbed & utilized
for energy by the body.

59.  Dietary lactose is hydrolyzed in small
intestine into glucose & galactose by lactase.
 In lactating mammary, lactose is synthesized
from glucose by duct epithelium.
 Present in breast milk is a good source of
energy for newborn.
 Deficiency of enzyme leads lactose
intolerance

61.  Sucrose- not hydrolyzed when give IV. Due
to lack of enzyme in blood.
 Presence of sucrose in the blood changes the
osmotic condition & causes a flow of water
from tissue to blood .
 Use it in edema like cerebral edema.

62.  Disaccharide
 Made up of D- galactopyranose and D –
fructofuranose .
 Joined by α 1-4 linkage .
 Neither absorbed nor hydrolyzed in GIT.
 Can be fermented.
 Due to its osmotic effect, draws more fluid
into intestine and soften the fecal matter
 Mild laxative.

63.  Contain two glucose molecule
 held together by α (1 , 4) linkage.
 Non reducing
 No osazone
 Source ;- fungi , yeasts
 Sugar of insect hemolymph.

64.  Polysaccharides are long polymers of
monosaccharides and their derivatives. These
polymers can be either linear or branched.
 According to their two main functions:
 energy storage ---- glycogen, starch
 structural components of cells……. cellulose
 Polysaccharides are two types:
 Homopolysaccharides
 Heteropolysaccharides

65.  Homoglycans - homopolysaccharides
containing only one type of monosaccharide.
eg:- starch, glycogen, cellulose, inulin
,dextrins & Dextran.
• Heteroglycans - heteropolysaccharides
containing residues of more than one type of
repeating units of monosaccharides.eg:-
hyaluronic acid, chondriotin sulphate etc.

66.  Starch or amylum is a carbohydrate consisting
of a large number of glucose units joined
together by glycosidic bonds.
 produced by all green plants .
 most common carbohydrate in the human diet
 staple foods as potatoes, wheat, corn, rice etc.
 Non reducing.

67.  starch is a white, tasteless and odorless
powder that is insoluble in cold water or
alcohol.
 It consists of two components :
 linear amylose
 branched amylopectin.
 starch contains 20 to 25% amylose and 75
to 80% amylopectin.

68.  α - amylose is a linear chain polymer
composed of glucose residues in α (1→4)
linkages.
 Its molecular weight varies from several
thousand to more than one million grams
(2,205 pounds) per mole.
 Hydrolyze by α –amylase, enzyme.
 Amylase are two types:- α –amylase, ß-
amylase.

69.  Amylopectin, like α -amylose, is composed
entirely of α -glucose, its α –glucose units
are joined by α (1→4) linkages & α (1→6)
linkage at branch points.
 Branches occur at every twelve to thirty units
along a chain of α (1→4) linked glucose .
 Amylopectin has one reducing end and many
non reducing ends. Amylopectin and α -
amylose are broken down by the enzyme
amylase.

70. α-amylase amylose
maltose
Starch dextrin (small units)
ß –amylase α- maltose
Amylopectin limit dextrin(large
chain)
maltose

72.  Starch forms a blue coloured
complex with iodine; this colour
disappears on heating; reappears
when cooled. Sensitive test for
starch.
 Hydrolysis for a short time dextrin
which gives violet colour with
iodine and is nonreducing

73.  Starch blue Reaction
with
Iodine
 Soluble starch Blue
 Amylodextrin purple
 Erthyrodextrin Red
 Maltose colorless

74.  Similar in structure to amylopectin
 highly branched structure
 Polymer of D-glucose with α -1,4-linked & α -
1,6 branches.
 Branching density is about three times higher
than in amylopectin .
 found only in animals
 Human beings store glycogen as reserve energy
fuel.
 Liver and muscles are main site of storage.

75.  The brain and other tissues require a constant
supply of blood glucose for survival. Some
tissues, particularly the liver and skeletal
muscle, store glucose in a form of glycogen , it
can be mobilized.
 Liver glycogen is used to as buffer the overall
blood glucose level.
 glycogen is synthesized when blood glucose is
high, and glycogen is degraded (with the
resulting glucose released into the blood
stream)

76.  when blood glucose is low, such as during
the early stages of a fast. Muscle uses its
glycogen stores for energy during strenuous
exercise
 Like amylopectin, it consists of α -glucose
residues in α (1→4) linkage, with α (1→6)
branch points.
 Present as spherical granules .
 Innermost core of glycogen contain a protein
glycogenin.

80.  Storage form of glucose & occurs
in liver & muscle. Formation of
glycogen from glucose is K/a
glycogenesis.
 Liver supplies glucose -1-P by
breakdown of glycogen is k/a
glycogenolysis, is converted to
glucose.

81.  Most abundant carbohydrate.
 Found in plants.
 Homopolymer of glucose like starch.
 ß-1,4 glycosidic linkages ( not α I,4 linkage )
 Not calorific value to human beings.
 Don't produce the enzyme cellulase.
 Very helpful from a diabetic point of view.
 Slow down absorption of glucose.

82.  It is formed by glucose units, linked by Beta-
1, 4 glycosidic linkages.
 The ß- linkage promotes intra-chain and
inter-chain H-bonds and van der Waals
interactions, that cause cellulose chains to be
straight & rigid, and pack with a crystalline
arrangement in thick bundles called micro
fibrils.
 Synthetic fibers, celluloid, nitrocellulose and
plastics are made from cellulose

83.  Not soluble in water; forms structurally stable
fibrils. The most abundant biological
molecule.
 major component of wood and plant cell
walls. Main constituents of the supporting
tissues of plants.

84. clinical Importance:-
 component of fiber in the diet.
 No metabolic requirement , high fiber diet is
associated with reduced incidence of a no.
of diseases like :-Diseases:-
-Cardiovascular disease
-colon cancer
-Diabetes mellitus
 increase the bulk of stool & prevents from
constipation.

85.  Polymer of D- fructose , linked by ß- (1-2)
glycosidic linkage.
 Levorotatory, MW. 5000
 Occur in the tubers of some plants.
 Is not utilized as food.
 Importance:-
 Role in the determination of glomerular
filtration rates.
 Estimation of body water volume.

86. Bacterial and yeast Polysaccharides.
• (α -1-6) linked poly-D-glucose.
• Branched with (α -1-3) ,(1-4),MW 1-million to
4-million.
- Produced by microorganism.
• Some sticky dextran by bacteria
(streptococcusmutant) makes dental plaque.
•Importance:-
used as plasma volume expander.
treatment of shock .

87.  When gives IV in cases of blood loses ,it
increase blood volume because, of their high
viscosity, low osmotic pressure, slow
elimination from the body ,they remain in
blood many hrs.
 Used for chromatography by gel filtration.
 Disadvantage:- can interfere with blood
grouping & cross matching, so blood sample
should be collected before IV. Of dextran.

88.  Dextrin:-incompletely digested product of
starch.
 Dextran:- high molecular weight
carbohydrate synthesized by bacteria and
yeast
 Dextrose :- other name of D-glucose .

89.  Polymer of sulfated galactose units .
 Obtained from seaweeds
 Biomedical importance :-
- Used in constipation.
- Used as culture medium for bacterial growth
& isolation.

90.  Measure of the effect of carbohydrates on
blood glucose level.
 GI determine how much each gram of available
carbohydrate in a food increases blood glucose
of a person following food relative to
consumption of glucose , which has GI of 100.
 it is expressed in comparison to the use of 50
gm of glucose as a reference standard meal.
 Usually determined by oral GTT.

91.  Food with carbohydrate that breakdown
quickly during digestion and release glucose
rapidly into blood have a high GI.
 Examples :- glucose , maltose, cornflakes,
white bread.
 Low GI :- fructose, fruits, vegetables.
 Clinical significance :- diabetics patients are
advised to have low GI foods to prevent
hyperglycemia.

93.  First discovered in mucin
 Glycoconjugates
 Heteroglycans appear in the form of
glycoconjugates.
 Proteoglycans: glycosaminoglycans + protein
 Peptidoglycans: bacterial cell wall
 Glycoproteins: O or N link to protein

94.  Heteropolysaccarides contain two or more
different kind of monosaccharides.
 One of these is an amino sugar usually N-
acetylglucosamine or N-acetyl galactoseamine
 Other monosaccharide usually a uronic acid –
glucuronic acid or iduronic acid .
 Extracellular support for organisms of all
kingdoms: the bacteria cell envelope, or the
matrix that holds individual cells together .
 Provides protection, shape and support to
cells, tissues and organs.

95.  Other common constituents are sulfate
groups linked to certain monosaccharides.
 heteropolysaccharides are associated with
proteins forming proteoglycans,
glycosaminoglycans or mucopolysaccharides
(since they are abundant in mucous
secretions).

96.  Glycosaminoglycans (mucopolysaccharides)
( contain amino sugar content )
complex carbohydrates , made up of
repeating units of monosaccharides & their
content of amino sugars, either D-
glucosamine or D-galactosamine and uronic
acids, L-glucuronic acid.
GAGs contain sulphate gp or not.
structure resemble a bottle brush.

97.  Their property of holding large quantities of
water and occupying space, thus cushioning
or lubricating other structures, is due to the
large number of OH groups and negative
charges on the molecules, which by
repulsion, keep the carbohydrate chains
apart.
 Examples are hyaluronic acid, chondroitin
sulfate, and heparin

98. Some generalized pts:
All have N- acetyl glucosamine except
chondroitin sulphate and dermatan sulphate
have N- acetylgalactoseamine
Keratan sulphate has no uronic acid but
galactose
All have glucuronic acid except heparin and
dermatan sulphate which have iduronic acid

99.  Occurrence of GAGs :-
 synovial fluid of joints.
 Vitreous humour of eye
 Arterial wall
 Bones & cartilage.
 GAG are six in numbers.

100.  Composition- ( N-acetyl glucosamine-glucuronic
acid)n
 Location :- synovial fluid of joints, vitreous
humour of the eye, loose connective tissue &
umbilical cord.
 Importance:- Act as barrier in tissues
 Gelly like substance
 lubricant in the synovial fluid of joints.
 strength and elasticity of cartilages and
tendons.
 Role in cell migration in embryonic tissue.
 Present in basement membrane of renal
glomeruli.

101. D-glucuronate
N-acetylglucosamine

102.  Composition- (ß-1,3 N-acetyl galactosamine
so ₄ -glucuronic acid)n
 Location :- at sites of calcification in bone &
cartilage, certain neurons.
 Importance-
 Provide an endoskeleton structure helping to
maintain their shape.
 Have role in compressibility of cartilage in
weight bearing.
 strength and elasticity of cartilages, tendons,
ligaments and walls of aorta.

103.  Role in sclera of eye:- is
present in sclera of the eye
where it has an important role
in maintaining over all shape
of the eye.
 Regulate flow & concentration
of cations round the cells.

104.  Chondroitin SO ₄ A:- N-acetyl galactosamine
so ₄ -glucuronic acid)n
 Chondroitin SO ₄ B:- N-acetyl galactosamine
& L-iduronic acid)n
 Chondroitin SO ₄ C:-similar to A
 Chondroitin SO ₄ D:- isolated from cartilage
of shark

106.  Composition- (ß-1,3 N-acetyl galactosamine
so₄-L-iduronic acid)n
 Location :- skin, blood vessels, heart, lungs.
 It may be related to coagulation and vascular
diseases and other conditions.
 Role in the transparency of cornea .
 Maintain the overall shape of eye.

108.  Composition- ( N-acetyl glucosamine so₄ -
galactose )n
 Not contain uronic acid
 Two type – I , II
 Type I :- present in the cornea of the eye
 Location :- Present in cornea, cartilage bone
and a variety of other structures as nails and
hair.
 Role in the transparency of cornea.

109. Composition- ( glucosamine so ₄ -iduronic
acid so ₄ )n
 Location :-intracellular component of mast
cell, lie on the wall of arteries, heart, lungs &
skin
 It is a potent natural anticoagulant produced
in the Mast Cells that causes antithrombin
bind to thrombin and produce inhibition of
blood coagulation.

111. • Hyaluronic acid - lubricant and cushioning
substance in Joints
 Chondroitin sulfate-most abundant
glycosaminoglycan in teeth and cartilage
 Keratan sulfate - important component of
cartilage
 Heparin - blood coagulation, therapeutic role
of atherosclerosis .
 Heparin sulfate - important in adhesion
between cells of the retina, cell to cell
interaction , glomerular filtration .

112.  Glycosaminoglycans are synthesized in the ER
and Golgi.
 They are degraded by lysosomal hydrolases.
A deficiency of one of the hydrolases results
in a mucopolysaccharidosis.
 These are hereditary disorders in which
glycosaminoglycans accumulate in tissues,
causing symptoms such as skeletal and
extracellular matrix deformities, and mental
retardation.

113.  Examples of these genetic diseases are Hunter
and Hurler syndromes.
 Autosomal recessive trait
 Hunter’s – X-linked
 These diseases, caused by different enzyme
deficits
 Clinical features
 physical deformities
 mental retardation
 Multiple organ affected
 Enlargement of organs like liver, heart, spleen.


114.  Are protein to which oligosaccharides are
covalently attached to their polypeptide
chain.
 Contain much shorter carbohydrate chain
than proteoglycans.
 Glycoprotein contain less than 4%
carbohydrate in the molecule.
 Mucoprotein contain more than 4%
carbohydrate .

116.  All the plasma proteins of human are
glycoproteins.
 Serve as hormones, eg;- chorionic
gonadotropin, thyroid stimulating hormone
(TSH)
 Serve as enzymes ,eg:- alkaline phosphates.
 Act as antibodies, eg; Igs, histocompatibility
antigens.
 Act as structural component , eg:- collagen.

117.  Role as lubricant & protective agent.
 Role as transport molecules. Eg:- transferrin
& ceruloplasmin.
 Play role in cell surface recognition sites.
 Also act as cell surface antigen.