Download MBBS Biochemistry PPT 47 Final Carbohydrate Chemistry Lecture Notes

Download MBBS (Bachelor of Medicine, Bachelor of Surgery) 1st year (First Year) Biochemistry ppt lectures Topic 47 Final Carbohydrate Chemistry Notes. - biochemistry notes pdf, biochemistry mbbs 1st year notes pdf, biochemistry mbbs notes pdf, biochemistry lecture notes, paramedical biochemistry notes, medical biochemistry pdf, biochemistry lecture notes 2022 ppt, biochemistry pdf.


Chemistry

and

Functions

of

Carbohydrates

SYNOPSIS

Introduction
Definition of Carbohydrates
Classification of Carbohydrates
Study of Biomedically Important

Carbohydrates:

Monosaccharides
Disaccharides
Polysaccharides
Mucoproteins and Glycoproteins.
Biomedical Importance of Carbohydrates.
Introduction

What are Carbohydrates?

Carbohydrates are organic

biomolecules abundantly present in

the nature.

Found in the cells of plants and

animals.

The term "Carbohydrate" was coined

by "Karl Schmidt".
Carbohydrates Biosynthesis

Carbohydrates are predominantly

biosynthesized by plants through

photosynthesis.

Glucose is synthesized in plants

from CO2, H2O, and solar energy

from the sun.

Photosynthesis


chlorophyll

6 CO2 + 6 H2O

C6H12O6 + 6 O2

Sunlight Glucose

(Simple Carbohydrate)



(+)-Glucose Starch or Cellulose

(Complex Carbohydrates Of Plants)



Animals and Human beings

cannot biosynthesize

Carbohydrates

predominantly.
To fulfill metabolic and

structural role in human

beings,

It is essential to ingest

carbohydrates through

food substances of plant and

animal origin.

Thus Carbohydrates are chief

constituents of human food.

R.D.A for Dietary Carbohydrates=

400-600 gm/day.
However in a critical

condition when cells are

deprived of Glucose

Human body biosynthesizes

Glucose using the non

carbohydrate precursors

present in body via

Gluconeogenesis.
Functions of Carbohydrates

Carbohydrates serve as

primary source of

energy/Fuel of body

( Metabolic role).

Carbohydrate (Glucose)

is oxidized in living cells

of human body to

produce CO2, H2O, and

energy(ATP).


Carbohydrates provide

skeletal framework to cells

,tissues, and organs of

body.(Structural role)

Carbohydrates are associated

to many other roles with

human beings.

DEFINITION OF

CARBOHYDRATES
Old Definition of Carbohydrates

Empirical formula/General formula for

simple carbohydrates : Cn (H2O)n

Where n = number of carbon atom

present in carbohydrate structure.

Old Definition-
Carbohydrates are "Hydrates of

Carbon"

Old definition is not valid since-
Certain Carbohydrates ?
Rhamnose did not fit in the

empirical formula of carbohydrates.

Certain non Carbohydrates ?
Lactate and Acetate fitted in the

empirical formulae.
Observe the following

chemical structures of

simple Carbohydrates:

Glucose and Fructose

Aldose

Ketose

(e.g., Glucose) have

(e.g., Fructose) have

an aldehyde group at a ketone group,

one end.

usually at C2.
Simple Carbohydrates has many

Hydroxyl groups (Polyhydroxy).

Simple Carbohydrates has carbonyl/

functional groups as Aldehyde or

Ketone.

Simple Carbohydrates(Glucose/Fructose)

repeatedly linked to form its condensed

complex carbohydrates for ex Starch,

Inulin.

The hydroxyl groups may be free

or substituted by any other

groups.

Simple Carbohydrates on

chemical reactions produces

derivatives of Carbohydrates.
New Definition of Carbohydrates

Carbohydrates are organic

biomolecules, abundantly

present in the plant and animal

bodies, chemically composed of

Polyhydroxy Aldehyde or

Polyhydroxy Ketone, their

condensed products or their

derivatives.



Classification Of Carbohydrates


Depending Upon Number of Saccharide Units

Four Main Classes of Carbohydrates

Monosaccharides

(1 Saccharide Unit)

Disaccharides

(2 Saccharide Units)

Oligosaccharides

( 3-10 Saccharide Units)

Polysaccharides

( More than 10 Saccharide Units)
Monosaccharides Sub Classification

Monosaccharides are sub

classified on the basis of:

Functional Group
Number of Carbon atoms.

Number of

Aldoses

Ketoses

Carbon Atoms

(Aldehyde-CHO)

(Ketone -C=O)

3

Aldo Triose

Keto Triose

Triose

Glyceraldehyde

Di HydroxyAcetone

4

Aldo Tetrose

Keto Tetrulose

Tetrose

Erythrose

Erythrulose

5

Aldo Pentose

Keto Pentulose

Pentose

Ribose, Xylose, Arabinose

Ribulose, Xylulose

6

Aldo Hexose

Keto Hexose

Hexose

Glucose, Galactose ,Mannose

Fructose

7

Aldo Heptose

Keto Heptulose

Heptose

SedoHeptose

SedoHeptulose
Disaccharides

Disaccharides has 2

Monosaccharide units

linked by glycosidic bond.

Disaccharides may be

reducing or non reducing

Type Of Disaccharides

Reducing Disaccharides ?

Lactose (Glu-Gal)
Maltose (Glu-Glu)

Non reducing Disaccharides-

Sucrose(Glu-Fru)
Oligosaccharides Sub Classification

Oligosaccharides has 3-10

Monosaccharide units linked

by glycosidic bonds.

Oligosaccharides are sub

classified on the basis of

number of Saccharide units.

Number of

Type Of Oligosaccharides

Monosaccharide

(3-10 Monosaccharide Units )

Units

3

Trisaccharides

Maltotriose (Glu-Glu-Glu)

Raffinose (Glu-Fru-Gal)

4

Tetrasaccharides

Stachyose (Glu-Fru-2Gal)

5

Pentasaccharides

Verbascose (Glu-Fru-3Gal)
Polysaccharide Sub Classification

Polysaccharides/ Glycans
contain more than 10, same/

different Monosaccharide

units linked by glycosidic

linkages.

Types of Polysaccharides

Homopolysaccharides/

Homoglycans-

Contains more than 10 same repeating

units.

Heteropolysaccharides /

Heteroglycans-

Contains more than 10, different

repeating units.
POLYSACCHARIDES/ Glycans

( More than 10 Monosaccharide Units )

Homopolysaccharides/ Homoglycans

( > 10 Same Repeating Units )

Glucosans

Fructosans

(Repeating Unit of Glucose/Polymer (Repeating Unit of

of Glucose)

Fructose/Polymer of

Starch

Fructose)

Glycogen

Cellulose

Inulin

Dextrin

Dextran

Hetero Polysaccharides

( More than 10 Different

Repeating Units )
Animal

Heteropolysacchrides

Mucopolysaccharides (MPS)

OR

Glycosaminoglycans (GAGs)

Types And Examples of

Mucopolysaccharides
Acidic Non Sulfated MPS:

Hyaluronic Acid

Acidic Sulfated MPS:

Heparin

Heparan Sulfate

Chondritin Sulfate

Dermatan Sulfate

Keratan Sulfate

Neutral MPS:

Blood Group Substances

Plant Heteropolysaccharides

Agar
Pectin
Lignin
Gum
What are Sugars?

Sugars are chemically simple

Carbohydrates Monosaccharides and

Disaccharides.

Sugars are Crystalline Solid substances.
Soluble in water
Sweet in taste
Structure possess asymmetric /chiral

carbon atoms/stereogenic centers.

The carbonyl/

functional groups of

Carbohydrates may be

present as free or

bound (involved in

glycosidic bonds).
Types Of Sugars

Reducing Sugars
Non Reducing

Sugars

Reducing Sugar

Sugar structure possessing free or

potential(reactive) aldehyde or

ketone group is termed as

reducing sugar.

Reducing sugars show reducing

property efficiently in alkaline

medium and reduces certain

metallic ions as- Cu++;Bi++;Fe+++
Reducing Sugars answer following

tests positive

Benedict's Test
Fehling's test
Nylander's Test
Form Osazones.
Reducing Shows Mutarotation

(Change in Optical activity)

Examples Of Reducing Sugars

All Monosaccharides are reducing sugars.
Monosaccharides are strong reducing

agents.

Monosaccharides?

Ribose, Glucose, Galactose, Fructose.

Disaccharides are weak reducing agents.
Reducing Disaccharides-

Lactose, Maltose.
Non Reducing Sugars

Sugar structure not possessing

free or potential aldehyde or

ketone group in its structure is

termed as non reducing sugar.

Non reducing sugar does not

show reducing property and do

not reduce metallic ions.

Non reducing sugars give following

reducing tests negative.

Benedict's Test
Fehling's test
Nylander's Test
Do not form Osazones
Non Reducing sugars do not exhibit

Mutarotation (Change in Optical activity)
Examples of Non reducing Sugars

Non reducing Disaccharides.

Sucrose (Biomedically Important)
Trehalose (Glu-Glu linked with

(1-1) glycosidic bond)

Polysaccharides/Complex

Carbohydrates are Non reducing.

Sugar/Sugar Derivatives

Percent

Sweetness

Glucose

75

Fructose

175

(Sweetest Sugar)

(Highest)

Galactose

30

Sucrose

100

Lactose

20

Maltose

30

Xylitol

250
Non Carbohydrate Percent Sweetness

Synthetic Sweetners

Saccharin

45,000 times

Aspartame

18,000 times

(Asp-Phe)

Thaumatin and

10,000 times

Monellin

Cyclamate

1000 times

Biomedical Importance of Sugars

Sugars are sweetening

agents used in

preparations of fruit

juices, sweet recipes

which gives delicious taste.
Sugars have dietary and

calorific value.

Ingested sugars are digested

,absorbed and assimilated to

produce chemical form of

energy ?ATP, which is further

used for body activities.

Carbohydrates are

Optically Active and

Show Stereoisomerism
All Carbohydrates except Di Hydroxy

Acetone(DHA) possess asymmetric

carbon atoms in their structure.

Presence of Asymmetric carbon atoms

confer two properties:

Optical Activity
Stereoisomerism.

Optical Activity

Optically active solutions when

placed in the tube of Polarimeter.

If moves the plane of polarized

light toward right are dextro

rotatory (d/+).

If moves the plane of polarized

light toward left are laevo rotatory

(l/-).
Stereoisomerism

Stereoisomerism is

due to presence of

chiral carbon

atoms/stereogenic

centers.
Stereoisomers are type of

isomers

Which have same chemical and

molecular formula,

The structure slightly differs in

the spatial orientation of

groups around the carbon atom.

Biomedically Important

Monosaccharides
Monosaccharides (Simple Sugars)
Monosaccharides are simplest class

of Carbohydrates.

They are composed of one

saccharide unit.

Monosaccharides cannot be further

hydrolyzed.

Monosaccharides are building

blocks/monomeric units of higher

forms of Carbohydrates.

Glyceraldehyde/Glycerose

Simplest Carbohydrate

(Reference sugar)
Glyceraldehyde is

a Monosaccharide

Chemically ?

Aldo Triose

C3H6O3

Occurrence/Sources of Glyceraldehyde

In Cytoplasm of cells
Biomedical Importance's

Glyceraldehyde -3-Phosphate

is an intermediate of

Glycolysis and HMP shunt.

Glyceraldehyde is reduced

to Glycerol which is used

during Lipid and Glucose

biosynthesis.

DihydroxyAcetone

It is a Monosaccharide

DHA is a Functional

Isomer of Glyceraldehyde.
Chemistry Of DHA

Dihydroxy Acetone is a

Keto Triose.

C3H6O3
DHA has no chiral atom

in its structure.
Occurrence/Sources Of DHA

In Cytoplasm of Cells

Biomedical Importance's Of DHA

Dihydroxy Acetone

Phosphate(DHAP) is an

intermediate of Glycolysis.

DHAP is readily

interconvertable to

Glyceraldehyde -3-PO4.
Erythrose

Chemistry :

Erythrose is a Monosaccharide

Erythrose is an Aldo Tetrose

C4(H2O)4
Occurrence/Sources :
In Cytosol of cells
Biomedical Importances :
Erythrose -4-Phosphate is an

intermediate of HMP shunt.

Ribose

Chemistry :

Ribose is a Monosaccharide.
Ribose is an Aldo Pentose
C5(H2O)5
Occurrence/Sources :

In cells

Biomedical Importances of Ribose :

Ribose is an important component of

Ribonucleotides which forms RNA.

Ribose is component of certain Nucleotide

Coenzymes-

ATP, NAD+, NADP+,FAD

Deoxyribose

Deoxyribose is a

Monosaccharide

Derived from Ribose/

Derivative of Ribose
Chemistry :

Deoxyribose is a Aldo Pentose
Deoxyribose has one Oxygen atom

less than Ribose at C2.

Deoxyribose has no ?OH group at

C2

Instead has ?H at C2.
Occurrence/Sources :
In cells
Biomedical Importances Of

Deoxyribose :

Deoxyribose is a component of

Deoxyribonucleotides which

forms DNA.

Arabinose

Arabinose is a

Monosaccharide

Chemistry :
Arabinose is a Aldo Pentose
C5(H2O)5
Occurrence/Sources:
Gum Arabic and Cherries.
Biomedical Importances
Arabinose is a component

of Glycoproteins.
Xylose

Xylose is a Monosaccharide

Chemistry :
Xylose is an Aldo Pentose

C5(H2O)5
Occurrence/ Sources :
Wood Gum
Biomedical Importances :
Xylose is a component of

Glycoproteins and Proteoglycans

Xylulose

Xylulose is a

Monosaccharide

Chemistry :
Xylulose is a Keto Pentose

C5(H2O)5
Occurrence/ Sources :
In Cells
Biomedical Importances of Xylulose:
Xylulose -5-Phosphate is an

intermediate of HMP Shunt.

Xylitol reduced compound of Xylulose

is used as sweetener (250% Sweetness).
Ribulose

Chemistry:

Ribulose is a

Monosaccharide

Ribulose is a Keto

Pentose

C5(H2O)5

Occurrence/ Sources :
In Cytosol of cells.
Biomedical Importances

of Ribulose:

Ribulose-5-Phosphate occurs

as an intermediate of HMP

Shunt.
Glucose

Grape sugar
Chief blood sugar
Main sugar of body cells.
Also termed as Dextrose

Chemistry of Glucose

Glucose Chemically ?
Aldo Hexose.
Molecular Formula-
C6H12O6
C1 is an Anomeric

carbon of Glucose.

C1 has

carbonyl/Functional

group.

Structures Of Glucose
Cyclic forms for sugars

Fischer projections for a D Glucose

7P1-95

Fischer's and Haworth's Projection

Fischer's Projection

Cyclization of Glucose to hemiacetal is

spontaneous to form stable ring structures.

Haworth's Projection

Gluco Furanose -5 membered ring with Oxygen

atom in it.

Gluco Pyranose -6 membered ring with Oxygen

atom in it.
Monosaccharides can cyclize to

form Pyranose / Furanose forms

b =64%

a = 36%
Chair Conformation Of Glucose

Blood Glucose is more

thermodynamically stable in

D Glucopyranose form.
Occurrence/Sources of Glucose

Glucose is found in free or bound

state in nature.

Glucose is a component of

Disaccharides and Polysaccharides.

Glucose found-In fruits, human

blood and body cells.

Physical properties of Glucose

Glucose possess asymmetric/chiral

carbon atoms in its structure, this

confers 2 physical properties:

Optical Activity
Stereoisomerism
Optical Activity of Glucose

Optical activity for an aqueous

solution of Glucose is

dextrorotatory(+/d)

It rotates the plane of plain

polarized light in Polarimeter

towards right.

Hence Glucose is also termed

as Dextrose.

Specific rotation of Glucose

optical activity:

Pure -D Glucose = specific rotation

+112.2 ?

Pure -D Glucose = specific rotation

+18.7 ?


Isomers of Glucose

Cyclic structure of Glucose posses 5

asymmetric carbon atoms.

The number of isomers is 2n, where n is

the number of asymmetric centers.

According to Vant Hoff rule 25
Glucose posses 32 possible Isomers.

Functional / Structural Isomers of

Glucose

Glucose (Aldo Hexose) and

Fructose (Keto Hexose) .

These are Functional Isomers

their structure differs only at

functional groups.
Stereoisomer's Of Glucose

Stereoisomers are type of

isomers which have same

molecular formula; structure

differs only in the orientation

of groups in space.

Glucose Stereoisomers

D and L Glucose
Anomers
Epimers
D and L Glucose

Enantiomers/ Mirror images

of each other/Left and Right

Hand

Non superimposible/Non

overlapping.


To identify D and L Glucose

Look at the penultimate carbon atom

of Glucose (C5) /Farthest assymetric

carbon atom from carbonyl carbon

atom.

In D Glucose -OH is at R.H.S.
In L Glucose -OH is at L.H.S.

Enantiomers
Physical and chemical

properties of Enantiomers are

same, except optical rotation.

Sugars present in human

body are of `D' series.

Enzyme Racemase

interconvert `D'

and `L' isomers.
Anomers

-Glucose and -Glucose.
Anomers has group variations

at C1 Anomeric carbon atom of

Glucose .

In Fischer's projection at C1
-Glucose has -OH group at

R.H.S

In Fischer's projection at C1
-Glucose has ?OH group at

L.H.S.
Glucose anomers of

Haworth's projection shows

as follows.

-Glucose has -OH group

below the plane.

-Glucose has OH group

above the plane.
In the body

physiologically the most

thermodynamically

stable form of Glucose

is D Glucopyranose .
Anomerism

Glucose anomers are not stable

and tend to interconvert

constantly by opening and

reclosure of ring.

Anomerism is interconversion of

one form of anomer to another.

Anomerism exhibit Mutarotaion.

Epimers

Epimers are stereoisomers which

has variation in the orientation of

groups at C 2/ C3 / C4 of Glucose.

Epimers of Glucose

Galactose (C4 Epimer)
Mannose (C2 Epimer)
Mannose

Galactose

(C2 Epimer)



(C4 Epimer)

When Mannose and Galactose

structures are compared there

is variation at two different

carbon atoms (C2 and C4).

Mannose and Galactose are

not Epimers but they are

"Diastereoisomers".
Mutarotation

Mutarotation is

change in specific

rotation of an optically

active substance.

Criteria for an optically

active substance to exhibit

Mutarotaion:

Anomerism:
In aqueous solution the optically

active substance should exist in two

or more stereoisomeric forms by

ready interconversions.
Glucose Exhibits Mutarotation

Glucose in aqueous solution shows

`Anomerism'.

Glucose in aqueous solution

readily interconvert from

Glucose to Glucose and attain

an equilibrium mixture to exhibit

mutarotation.
Mutarotation is a physico chemical

property

Shown by certain optically active

substances ,who in aqueous solution has

capacity to interconvert from one

stereoisomeric form to other and attain

a constant equilibrium mixture,

This changes an initial specific rotation

to a constant specific rotation with the

passage of time.

Chemical Properties

OR

Chemical Reactions

OR

Derivatives Of Glucose
Reduction Reaction Of Sugars

Reduction Reaction

Glucose Sorbitol

(Sugar) (Sugar Alcohol)
During reduction reaction

the C1 carbonyl group

(-CHO) is reduced to primary

alcohol group (-CH2OH).

Sorbitol is

Polyol/Polyhydroxy Alcohol.
Sugar Alcohols taken in food are

of less calorific value.

They yield half energy in

comparison to sugars.

They are poorly absorbed.
Sugar alcohols if ingested reduces

weight.

They are prescribed for Diabetics.

Abnormal levels of Sorbitol found

in Diabetics, leads to Cataract

Excess Blood Glucose in

Diabetics, get reduced to

Sorbitol which further

deposits in the lens of eye

and forms Cataract.
Oxidation Reaction Of Sugar

Gluconic Acid

(Aldonic Acid)



(-CHO to -COOH)

Oxidation Reaction

Glucose



Glucuronic Acid

(Uronic Acid)
(-CH2OH to -COOH)
Glucosaccharic Acid

(Dibasic Aldaric Acid)



(-CHO &-CH2OH to ?COOH)
Aldehyde oxid'n
aldonic

acid

Terminal CH2OH

oxid'n Uronic acid

Aldehyde + Terminal CH2OH oxid'n
Aldaric acid/Saccharic acid
Uronic Acid of Glucose

Glucoronic acid is component

of Mucopolysaccharides.

Glucuronic acid serve as

conjugating agent in

detoxification reactions.
N-Glucosamine
N Acetyl Glucosamine
N Acetyl Galactosamine
Are Important constituents

of Mucopolysaccharides,

Glycoproteins and

Glycolipids



Glucose





Esteification

Glucose -6-Phosphate

Phosphorylation Reaction (Robinson Ester)

OR

Glucose-1-Phosphtae

(Cori Ester)
Reducing Property Of Glucose

Reducing property of

Glucose is Enolization/

Tautomerization reaction.

Glucose show efficient

reducing property in

alkaline medium .
Glucose in alkaline

medium forms Enediol

Enediol is a strong

reducing agent which

reduces cupric ions to

cuprous ions.

Glucose give positive test results

for following reducing tests:

Benedicts Test
Barfoeds Test
Fehlings Test
Nylanders Test.
Benedicts Test-Reduction of Cupric

ions in mild alkaline medium.

Barfoeds Test-Reduction of Cupric

ions in weak acidic medium.

Fehlings Test- Reduction of Cupric

ions in strong alkaline medium.

Nylanders Test-Reduction of

Bismuth ions in strong alkaline

medium.

Glycosides

Glycosides are derivatives of sugar.
Glycosides has Aglycone moiety linked to

C1 (anomeric carbon atom) of sugar by an

acetal linkage.

Sugar Acetal Linkage

Aglycone

Moiety
Aglycone moieties-
(Non Sugar, Hydroxyl group

containing compounds)

?Methanol
?Sterol
?Phenol
?Glycerol

Types of Glycosides-

Glucoside

(Contains Sugar as Glucose)


Galactoside

(Contains sugar as Galactose)
Occurrence and Uses of

Glycosides

Glycosides are naturally

occurring substances

present in plants and

animal bodies; which are

extracted and used as

drugs.

Glycosides

Examples and Therapeutic Use
S.No

Examples of

Therapeutic Use

Glycosides

1

Cardiac Glycosides

In treatment of cardiac

Digoxin /Digitonin

insufficiency.

Ovabain

2

Phlorizin

In treatment of Diabetes

(Glucose Transporter Inhibitor) mellitus.

3

Streptomycin

Antibiotic used to treat

bacterial infections.

4

Glucovanillin

Flavoring agent in Ice

creams and Puddings.

Biomedical Importance of Glucose

Glucose is a reduced compound and

has bond energy in its structure.

Glucose in body cells

Oxidized/Catabolized to liberate

chemical form of energy-ATP.

1 Glucose molecule on complete

oxidation produces 32 ATPs.
Glucose serve as primary source of

energy to all body cells.

Glucose is an universal fuel of fetus.

Brain, Erythrocytes ,lens cells, spinal

cord, peripheral nerves are completely

dependent on Glucose for its energy.

After well fed condition the free and

excess body Glucose is transformed to

Reservoir /Storage forms of Glucose

? Starch (In Plants)

? Glycogen (In animals)

Glucose still in excess is transformed to

Fat (TAG) and stored as depot fat.

(Unlimited).
Glucose is used for biosynthesis

of:

Glucuronic acid
Glucosamine
N-Acetyl Glucosamine
Galactose
Non essential amino acids
Glycosides

Galactose

Chemistry of Galactose

Galactose is a Monosaccharide
Aldo Hexose
C4 Epimer of Glucose
Occurrence/Sources

Galactose is never found free

It is a component of :

Milk Sugar Lactose
Mucopolysaccharides
Glycolipids and Glycoproteins.
Galactose on reduction form

Dulcitol.

Galactose on strong oxidation

forms Mucic acid.

(Galactosaccharic acid).

Galactose is abnormally elevated

in blood and excreted in urine ?

GALACTOSEMIA.

Biomedical Importance

Galactose has dietary and

calorific value.



Galactose is transformed to

Glucose in Liver and metabolized.
Galactose is used in biosynthesis of

Mucopolysaccharides,
Glycoproteins, Glycolipids.

Galactose along with Glucose forms

Lactose in lactating mothers .

Galactose is part of

nerve and brain

biochemicals, so

milk is essential to

infants.
Mannose

Mannose is a Monosaccharide
Chemically -Aldo Hexose
C2 Epimer of Glucose

Occurrence/Sources of Mannose

In Plants
Mannan (Polymer of Mannose)
Biomedical Importance Of

Mannose

Mannose component of
Glycoproteins.

Mannitol reduced compound of
Mannose is used as Diuretic to
treat Acute Renal failure.

Fructose

Fructose is a

Monosaccharide

Fructose is Sweetest Sugar.
Laevulose (Laevorotatory)
Chemistry Of Fructose

Fructose is a Keto Hexose
C6H12O6

C2 is anomeric carbon of

Fructose
Occurrence/Sources Of Fructose

In Fruits, Honey
Body cells, Semen.
Fructose is component

of Sucrose.
Fructose is more stable in
D Fructofuranose form.
Selivanoff `s test is characteristic

test for Fructose.

(positive result-Cherry red

color).

Fructose on reduction forms

Sorbitol and Mannitol.

Fructose-6-PO4 (Neubergs Ester )
Fructose-1,6- Bis Phosphate

(Harden Young Ester).

Abnormal excretion of Fructose in

urine is noted in persons suffering

from Essential Fructosuria.
Biomedical Importance Of

Fructose

Fructose has dietary and calorific

value.

In Liver Fructose is transformed to

Glucose and metabolized.

Fructose present in semen serves as

nutrient for Sperms.
Biomedically Important

Disaccharides
Disaccharides are class of

Carbohydrates, chemically

composed of two, same or

different Monosaccharide

units, linked by glycosidic

bond.

General Formula of

Disaccharides

Cn(H2O)n-1
Glycosidic Bonds

Glycosidic bonds are

Acetal/ Ketal bonds

involving the anomeric

carbon of Monosaccharides.

The Aldehyde/Ketone groups

participate in glycosidic bond,

Its involvement looses reducing

property since, they wont remain

free.
Glycosidic bonds are formed

with the interaction of two

hydroxyl groups of adjacent

sugar

residues(Monosaccharide)

with an elimination of water

molecule.
Glycosidic

Linkage

Glycosidic bonds are

covalent, strong bonds

,linking one Monosaccharide

to another.
Glycosidic bonds are formed

with / configuration.

Different glycosidic bonds

form a different molecule

with different properties.

Types of Glycosidic bonds:

? ( 1-4)
? (1-6)
? 1-2
? (1-1)
? (1-4)
Reducing end- End with free

anomeric carbon, not involved

in formation of glycosidic bond.

Non reducing end- End with

no free anomeric carbon, since

involved in formation of

Glycosidic bond.

Types of Disaccharides
Reducing Disaccharides

Lactose (Milk Sugar)
Maltose
(Malt Sugar, Product of Starch digestion))

Isomaltose (product of Starch digestion)
Lactulose (Laxative)
Cellobiose ( Product of Cellulose)

Non Reducing Disaccharides

Sucrose (Cane Sugar )
Trehalose
Lactose

(Milk Sugar)

Components and Linkage

of Lactose

Lactose is a Reducing Disaccharide



(1-4 ) glycosidic bond

D Galactose

D Glucose



Source / Occurrence Of Lactose

Milk and Milk products.
Lactating Mothers body.

Biomedical Importance Of Lactose

Lactose has dietary and calorific

value.

GIT enzyme Lactase digests

Lactose by cleaving (1-4)

glycosidic bond and releases free

Galactose and Glucose.
Lactase deficiency in GIT leads

to suffer from Lactose

Intolerance.

Certain bacteria can ferment

lactose to lactic acid - souring of

milk

(Lactobacillus).
Lactose may occur in urine during

trimester of pregnancy.

Maltose

Maltose is a reducing

Disaccharide

Malt Sugar
Components and Linkage Of

Maltose

D Glucose - D Glucose
(1-4 ) glycosidic bond

Glucose to form Maltose

+

Condensation

Hydrolysis

H2O


Source / Occurrence Of Maltose

Malt grain, Germinating seeds,

Maltova.

In human GIT, source of Maltose

is through Starch and Glycogen

digestion by Amylase

activity.
Maltose is obtained in

GIT as an end product of

Starch and Glycogen

digestion.

Biomedical Importance Of

Maltose

Maltose has dietary and

calorific value.

GIT enzyme Maltase digests

Maltose by cleaving (1-4)

glycosidic bond and releases

two Glucose units.
Isomaltose

Isomaltose is a reducing

Disaccharide.

Isomaltose is a product

of Starch and Glycogen

digestion.

Components and Linkage Of

Isomaltose

D Glucose - D Glucose
(1-6 ) glycosidic bond
Source /Occurrence Of Isomaltose

In human GIT

Isomaltose is obtained

from Starch and

Glycogen digestion

by -Amylase activity.
Biomedical Importance of

Isomaltose

Isomaltose has dietary and

calorific value.

Isomaltose is digested by GIT

enzyme Isomaltase to release

two Glucose units by cleaving

(1-6 ) glycosidic bond.

Cellobiose

Cellobiose is a reducing

Disaccharide.

Disaccharide obtained from

Cellulose Digestion.
Components and Linkage Of

Cellobiose

D Glucose - D Glucose
(1-4 ) glycosidic bond
Source / Occurrence of Cellobiose

Cellobiose obtained from

Cellulose digestion In GIT of

ruminants ( Cattle) .

Cellobiose is absent in

human GIT, since enzyme

Cellulase is absent which do

not digest Cellulose.

Biomedical Importance of

Cellobiose

Cellobiose is absent in

human beings.

Not of biomedical

Importance.
Lactulose

Lactulose is a

Reducing

Disaccharide

Type, Components and

Linkage of Lactulose

D Galactose - D Fructose
(1-4 ) glycosidic bond
Source / Occurrence Of Lactulose

In Plants
Lactulose:
Prepared by

alkaline

rearrangement of

lactose

Biomedical Importance Of

Lactulose

Lactulose has therapeutic

value; act as osmolar

laxative.

Relieves Chronic

Constipation.
Oral administration of

Lactulose relieves hyper

Ammonaemia in patients of

Hepatic Encephalopathy.

Treatment of Systemic

Encephalopathy By Lactulose.

Mechanism of action:
Lactulose is not digestible.
Bacterial flora convert it to Lactic and

Acetic acids that irritate the intestinal

wall.

Increases acidity of intestine ,this

moves ammonia from blood to the

intestine for neutralization.

Relieves Hyperammonaemia.
Sucrose

Sucrose is a Non Reducing Disaccharide
Cane sugar/ Common Table Sugar /Beet sugar

Components and Linkage Of

Sucrose

D Glucose- D Fructose
1- 2 glycosidic bond.

Why Sucrose is Non reducing?

Glucose (C1) and Fructose(C2)

anomeric carbon atoms are

involved in formation of

Glycosidic bond.

No free anomeric carbon

atoms.

Hence Non reducing.

Sucrose has no

free aldehyde

/ketone group

hence non

reducing
Sucrose is

dextrorotatory (d/+)

with specific rotation

+66.50.

Source /Occurrence Of Sucrose

In Plants ? Sugar cane,

Beet root.

Commercially prepared

from sugar cane.
Invert Sugar

Invert sugar is a product

of Sucrose hydrolysis.

Invert Sugar is a product

of Inversion Process.
Invert Sugar is a

hydrolytic mixture of

free Glucose and

Fructose obtained from

Sucrose hydrolysis.

Inversion process

A non reducing and

dextrorotatory Sucrose, on acid

hydrolysis/by action of enzyme

Invertase ,

Produces a hydrolytic mixture of

free, Glucose(+52.50) and

Fructose(-930) which is reducing

and laevorotatory(- 20.40).
Invert Sugar is Reducing.

Invert sugar is laevorotatory.

(since Fructose has high magnitude of optical

rotation -930)

Invert Sugar is sweeter than Sucrose

(since it contains free Fructose,a sweetest

sugar)

Uses Of Invert Sugar

Sweetening agent as it

is more sweet than

Sucrose.

Used in adulteration of

Honey.
Biomedical Importance Of Sucrose

Sucrose has dietary and calorific

value.

Sucrase or Invertase enzyme of

GIT cleaves 1- 2 Glycosidic

bond of Sucrose and release free

Glucose and Fructose ? i.e. Invert

Sugar.

Biomedically Important

Oligosaccharides
Oligosaccharides are

composed of 3-10

Monosaccharide units linked

by glycosidic bonds.

Oligosaccharide may be

branched or unbranched

chain.

Dietary Oligosaccharides are

not digested by human hence

has no calorific value.

Oligosaccharides are

components of Glycoproteins.
Biomedically Important

Polysaccharides/Glycans

Polysaccharides are complex

class of Carbohydrates,

Chemically composed of more

than ten, same or different

Monosaccharide units or their

derivatives

Repeatedly linked by glycosidic

linkages.
General

Formula of

Polysaccharides

(C6H10O5 )n

Iodine test is a

characteristic

test for

Polysaccharides
Iodine test is based on Physical

property of adsorption.

Iodine get adsorbed on complex

structure of Polysaccharides to

give characteristic color.

Homopolysaccharides

Homopolysaccharides are type

of Polysaccharides composed of

more than 10, same type of

Monosaccharide units

repeatedly linked by glycosidic

bonds.
Glucosan

Type of Homopolysaccharide
Repeating unit,of Glucosan is

Glucose

Glucosan is a Polymer of

Glucose.

Examples Of Glucosans

Starch
Glycogen
Cellulose
Dextrin
Dextran
Fructosan

Type of

Homopolysaccharide

Repeating unit in

Fructosan is Fructose.

Fructosan is a Polymer of

Fructose.

Example Of Fructosan

Inulin
Starch



Plant Homopolysaccharide

Chemistry Of Starch

Starch is Glucosan
Repeating Unit -
D Glucose (approx 7000)
Components of Starch-
Amylose and Amylopectin
Amylose

Amylose is 15-20%
Linear structure
D Glucose linked by

(1-4) glycosidic bond.


Amylopectin



Amylopectin is 80-85 %
Branched structure
Branching point appears after every
25-30 Glucose units.
It has (1-6) glycosidic bond at branching

point.

(1-4) glycosidic bonds in linear structure.

Starch is white ,odourless, tasteless

powder .

Starch is insoluble in cold water, but get

solubilized on heating and form gel

/paste.

Starch is a non reducing Carbohydrate.
Starch -Negative Benedicts Test.
Starch on Iodine reaction gives blue

color.
Source/Occurrence Of Starch

Plants- Seeds, Tubers, Roots, Raw fruits.

Dietary Sources of Starch.

Grains- Rice ,Wheat, Jawar, Bajra
Potatoes
Beetroot.
Sago (Tapioca)
Vermicelli
Suji.
Raw Mangoes

Biomedical Importance Of Starch

Starch is a storage form of Glucose

and serves as reservoir of energy in

plants.

To humans Starch is a predominant

form of dietary Carbohydrate

ingested through foods which has

high dietary and calorific value.
Digestion of Starch

In mouth- by salivary Amylase
In intestine -by pancreatic Amylase

Amylase cleaves, (1-4) glycosidic

bonds of Amylose and Amylopectin and

releases Maltose and Isomaltose.

Maltose and Isomaltose is then

digested by Maltase and

Isomaltase to release free Glucose

units.

Thus Starch on digestion gives

thousands of free Glucose units

which have high calorific value.
Glycogen



Animal Homopolysaccharide
Animal Starch

Chemistry Of Glycogen

Glycogen is chemically

Glucosan.

Repeating Unit ?

D Glucose (25-30 thousand

Glucose units)
Glycogen is like Amylopectin

structure ,but it is highly branched

Branching points appear after

every 8-10 Glucose units, linked by

(1-6) glycosidic bond.

Linear structure has Glucose linked

with (1-4) glycosidic bond.



Glycogen
Glycogen has more a(16)

branches.

The highly branched structure

permits rapid glucose release

from glycogen stores, in muscle

during exercise.

Source/Occurrence Of Glycogen

Glycogen is present in

animal-

Liver (75 gm)

Muscle (125 gm).
Non-Veg diet is a source

of dietary Glycogen to

human beings, which has

high dietary and calorific

value.

After well fed condition, free

and excess of Glucose is

condensed to Glycogen via

Glycogenesis.

Rate of Glycogen synthesis ?

Liver- 6-8 %,
Muscle 1-2 %
Glycogen is broken

down to Glucose via

Glycogenolysis when

body Glucose lowers in

fasting and starvation

condition.

Biomedical Importance Of

Glycogen

Glycogen is a storage form of

Glucose in animal and human body

after well fed conditions.

It serves as reservoir of Glucose

which can be used in emergency

conditions

( Fasting /Between meals )


Glucose stored in

polymeric/condensed

form minimizes osmotic

effects and occupy less

space.

Glycogen produces less

osmotic pressure and occupy

small space.

Glycogen is sparingly soluble in

water.

On Iodine reaction Glycogen

gives deep red color.
Dietary Glycogen in

GIT is digested by

- Amylase to Maltose

and Isomaltose and

finally to thousands of

Glucose Units.

Liver Glycogenolysis

in Human body

regulates Blood

Glucose levels in

fasting condition.
Muscle

Glycogenolysis

provides energy for

muscle activities in

fasting condition.



Cellulose

Non digestible carbohydrate

Cellulose serve as dietary

Fiber.
Chemistry Of Cellulose

Cellulose is a Glucosan
Repeating Unit - D Glucose.
(approx 2,500- 14,000 ).

Cellulose is a linear ,unbranched

structure where D Glucose units

repeatedly linked by (1-4 ) glycosidic

bonds.

Source/Occurrence Of Cellulose

Cellulose is an abundant carbohydrate of

nature exclusively present in Plants cell wall.

Dietary rich sources of Cellulose
Whole Grains (outer covering)
Green leafy vegetables
Cabbage, Cucumber
Legumes, Nuts, Beans
Dates
Fruits and Vegetable salads.
Biomedical Importance of

Cellulose

In plants Cellulose

present in cell wall

provides structural

and mechanical

support.



Wood, cotton and

paper are composed

primarily of cellulose.
In humans, dietary

Cellulose is not digested

and absorbed.

Enzyme Cellulase is absent

in human GIT.

Cellulose has no calorific

value.

Dietary

Cellulose in

humans serves

as dietary fiber.
Cellulose has Effect on Fecal Mass

Formation

Cellulose acts as a roughage.
It holds water ,helps in forming soft and bulky

feces.

Increases intra luminal pressure.
Reduces transit time of feces to remain in gut.
Eliminates daily, metabolic wastes and toxins

out of the body, through feces.

Defecation with greater ease and good

frequency.

Cellulose prevents

constipation, and reduces risk

of :

vcolon cancer
vvaricose veins
v diverticulosis of intestine
v hemorrhoids
Cellulose reduces the absorption

of :

Glucose
Cholesterol

Ameliorate the conditions of :

?Diabetes mellitus
? Atherosclerosis respectively.

Cellulose being non

calorific and

possessing high satiety

value helps in

managing obesity in

humans.
For maintenance of good health

ingest dietary fibers.

RDA for dietary fiber to

maintain good health:

Adults= 20-25 gm/day.
Children's= 5-10 gm/day.

Disadvantage of dietary

Cellulose-

It decreases absorption of

minerals.
Dextrin

Intermediate

hydrolytic

product of Starch

digestion

Chemistry Of Dextrin

Dextrin is a Glucosan
Repeating Unit - D Glucose.

Dextrin is less complex than starch

structure.

Dextrin is broken Starch molecule.
Types Of Dextrin

Amylodextrin -Violet to Iodine reaction

Erythrodextrin- Red to Iodine reaction

Achrodextrin -Colorless to Iodine reaction.
Source/Occurrence of Dextrin

In human GIT Dextrin is obtained as

an intermediate hydrolytic product

of Starch digestion by the action of

-Amylase activity.

Dextrin is Present in commercially

prepared infant foods.

Biomedical Importance Of Dextrin

Dextrin has mucilage

nature(sticky) hence used as

binding and adhesive agent.

Dextrin is used as infant food.
Dextran

Dextran is a Bacterial

Homopolysaccharide

Chemistry Of Dextran

Dextran is a Glucosan
Repeating Unit ? D Glucose.

Highly branched, complex, network

like structure

Glucose units linked by

(1-4) ,(1-6) and (1-3) glycosidic

linkages.
Source/Occurrence Of Dextran

Dextran is obtained from

Sucrose solution

incubated with bacteria

Leuconostoc

mesenteroides
Biomedical Importance Of Dextran

Dextran solution is high molecular

weight, viscous solution with

osmotic pressure equivalent to

plasma Albumin.

Dextran maintains blood volume

and osmotic pressure.

Dextran solution is used as
Plasma substitute/plasma

volume expander

Dextran infusion manages a

hemorrhagic case and

prevent from

hypovoluemic shock.
Sephadex

Sephadex is a modified Dextran.
The dextran macromolecules are cross-

linked to give a three-dimensional

network of polysaccharide chains.

Insoluble in water but absorb water

and swell.

Uses: In Chromatographic separation.

Fructosan

Homopolysaccharide

with repeating units as

Fructose.
Inulin

Diagnostic Carbohydrate
Diagnoses Kidney Function-

GFR of Kidney.

Chemistry Of Inulin

Inulin is a Fructosan
Repeating Unit-
D Fructose units (33-35 units)
Repeatedly linked by
(1-2) glycosidic bonds.
Source/Occurrence Of Inulin

Naturally present in Plants

Roots and tubers of

Dandelions

Onion and Garlic bulbs

Chicory Plant.

Biomedical Importance Of Inulin



Inulin is non digestible and non

absorbable form in human GIT, hence

have no calorific value.

Inulin solution infused intravenously

during Inulin Clearance Test,

checks Glomerular Filtration Rate

(GFR) of Kidney (120-125 ml/min).
Heteropolysaccharides

Heteropolysaccharides are type

of Polysaccharides composed of

more than 10 different

Monosaccharide units or

their derivatives repeatedly

linked by glycosidic bonds.

Animal Heteropolysaccharides
Mucopolysaccharides (MPS)

Human Heteropolysaccharides
Animal Heteropolysaccharides
Glycosaminoglycans (GAGs)

Mucopolysaccharides

were first isolated from

Mucin hence the name

Mucopolysaccharides.
Mucopolysaccharides

chemically composed of more

than 10 Monosaccharide units

and its derivatives repeatedly

linked by glycosidic bonds.

Mucopolysaccharides

are complex, long,

linear, unbranched,

polyanionic.
The Glycosaminoglycans has

Disaccharide repeating unit

linked by glycosidic bonds of

Uronic Acid

Amino Sugar


Uronic Acid ?
Glucuronic acid /Iduronic acid
(Iduronic acid is 5' Epimer of Glucuronic acid)

Amino Sugar-
Glucosamine / Galactosamine
(Acetylated or Sulfated or Both)
Jeanloz suggested the

term GAG's as these

biomolecules has

amino sugars as

repeating units.

Properties of GAG's

GAG's are polyanionic and acidic due

to presence of

?COO- and SO4-- -

GAG's are hydrophillic and attract

water and helps in distributing

water.
MPS due to repulsion of

charges:

It appear slippery or sticky

in appearance/mucus like

secretions

It expand to occupy large

space.

MPS/GAG's imparts following

physical properties-

Turgor

High Viscosity

High Density

High Buoyancy.
Body Mucopolysaccharides

Acidic Non Sulfated MPS:

Hyaluronic Acid

Acidic Sulfated MPS:

Heparin
Heparan Sulfate
Chondritin Sulfate
Dermatan Sulfate
Keratan Sulfate

Neutral MPS:

Blood Group Substances
Hyaluronic Acid

Acidic Non sulfated MPS

Repeating Disaccharide Unit

Glucuronic acid

NAcetylGlucosamine.

Occurrence and Functions Of
Hyaluronic acid

Hyaluronic acid is present as

ground substance/cementing
substance in extra cellular
spaces of connective tissue.
Hyaluronic acid in

synovial fluid of joints
and vitreous humor of
eye serve as lubricant
and shock absorbant.

Hyaluronic acid
around ovum
gives protection.
Hyaluronic acid

plays role in cell
migration during
morphogenesis.

Enzyme "Hyaluronidase " hydrolyses

Hyaluronic acid.

Hylauronidase present in head of sperm

, hydrolyzes the Hyaluronic acid present on

ovum which facilitates its penetration

and fertilization.

Snake venom is rich in Hyaluronidase,

thus snake bite hydrolyzes and liquifies the

Hyaluronic acid present in extracellular

spaces of cells ( TOXIN )
Heparin

Most Acidic Sulfated MPS.
Disaccharide Repeating Unit:

Glucuronate sulfate ( minor

)

Iduronate sulfate (major)
N-Glucosamine Sulfate.

?Heparin, a soluble

glycosaminoglycan found in granules

of mast cells and is highly sulfated.
?Heparin has an extended helical

conformation.
Occurrence and Functions Of

Heparin

Heparin present in blood vessels,

Liver, Lung, Spleen and

Monocytes

Heparin is a natural anticoagulant.
Prevents intravascular blood

coagulation by inactivating

clotting factor IX and XI.
When released into the

blood, it inhibits clot

formation by interacting

with the protein

antithrombin.

Heparin is an indirect

Thrombin inhibitor .

Rapid inactivator of Thrombin.
Thus antithrombotic agent.
Prevents intravascular blood

clotting.
Heparin releases

enzyme Lipoprotein

Lipase from endothelial

lining and serve as

coenzyme for it.

Lipoprotein Lipase is

Lipid clearing Enzyme

of blood.
Therapeutic Use of Heparin

Heparin is infused to prevent and

treat thrombous located in

vein/artery in MI cases.

Deep Vein Thrombosis.
Pulmonary Embolism
Strokes

Heparin(LMW Heparin)

injections are given to

M.I patients

To liquify blood ,prevent

thrombosis and clear

blood with lipids.
Heparan Sulfate



Acidic Sulfated Mucopolysaccharide

Disaccharide repeating units
Glucuronate Sulfate (major)/ Iduronate

Sulfate (minor)-N Acetyl Glucosamine

Occurrence and Functions Of

Heparan Sulfate

Heparan Sulfate present on

extracellular cell surfaces or

plasma membranes and serves

as receptors

Participate in cell growth, cell

adhesion, and cell -cell

communication.
Heparan sulfate in basement

membrane of kidney helps in

determining charge selectiveness

of Glomerular filtration.

Heparan sulfate are also

components of aorta, liver,

fibroblasts, synaptic and vesicles.

Chondritin Sulfate



Acidic Sulfated

Mucopolysaccharid

e
Disaccharide Repeating Unit
Glucuronate-
N ?Acetyl Galactosamine ?Sulfated.

Chondritin Sulfate A-4 sulfated.

Chondritin sulfate C-6 sulfated.

Occurrence and Functions Of

Chondritin Sulfate

Chondritin Sulfate is present in

connective tissues-bones,

cartilage, tendons .

It gives mechanical strength,

compressibility and support to

connective tissues.
Chondritin sulfate

present in cornea

give over all shape to

eye.

Dermatan Sulfate

Acidic Sulfated Mucopolysaccharide.
Chondritin sulfate-B / -Heparin

Disaccharide Repeating Unit
L-Iduronate-
N-AcetylGalactosamine-sulfated
Occurrence and Functions Of

Dermatan Sulfate

Dermatan sulfate especially present in

skin, blood vessels and heart valves

gives mechanical strength and

structural support to these tissues.


Dermatan sulfate plays structural

role in sclera of eye.

Keratan Sulfate

Acidic Sulfated Mucopolysaccharide

Keratan Sulfate is a MPS without Uronic

acid instead contains Galactose.

Disaccharide Repeating Unit
Galactose-N-Acetyl Glucosamine ?sulfated
Keratan sulfate present in cartilage,

aorta walls, gives structural

supports and mechanical strength.


Keratan sulfate present in cornea

and lens of eye has role in lens

transparency and shape of eye.

Blood Group Substances

Blood group substances are Neutral MPS

Components of Blood Group

substances

Galactose, Fucose,
N-Acetyl Glucosamine, N-Acetyl

Galactosimne


Blood group substances

neutral MPS, present

on cell surfaces of

Erythrocytes serves as

blood group antigens.

Applied aspects of

Mucopolysaccharides/ GAGs
On ageing or during

pathogenesis the biosynthesis of

certain specific

Mucopolysaccharide

/Glycosaminoglycan is either

increased or decreased leading

to disorders and manifestations.

Tumors cells-
Increased Hyaluronic acid

(Increases cell migration)

Decreased Heparan Sulfate

(Decreases cell adhesion)

This Increases Metastasis
Rheumatic Arthritis-
Rheumatic nodule shows

increased Hyaluronic acid

deposition.

Atherosclerotic

plaque-

Excess production of

Dermatan Sulfate

Decreased production

of heparin.
Osteoarthritis-
Imbalance biosynthesis

of Hyaluronic acid,

Chondritin Sulfate and

Keratan Sulfate

Mucoproteins

Or

Proteoglycans
Mucoproteins/

Proteoglycans

are conjugated

Proteins.

Mucopolysaccharides/
Glycosaminoglycans

(Prosthetic group) are never

found free but always covalently

linked to a core protein by N-

Glycosidic/O-Glycosidic bond to

formMucoproteins/Proteoglycan
O-Glycosidic /N-Glycosidic bond

Glycosaminoglycans

Core

Protein

Mucoproteins have

Carbohydrate

content more than

10 % and are viscous

in nature.
Mucoproteins/
Proteoglycans are

more complex,

viscous, highly dense,

molecular aggregates.
GAG chains

core

protein

Proteoglycans are

composed of as many as

200 GAG chains covalently

bonded to a core protein

via Serine/ Threonine side

chains.
Molecular weight range: 105 ? 107 Daltons.

GAG chains linked:

Hyaluronic acid

Chondroitin sulfate

Heparan sulfate

Dermatan sulfate

Keratan sulfate
Examples of Proteoglycans

Aggrecan

(Hyaluronate-Core Protein non

covalently linked In Cartilage)

Biglycan

Beta Glycan

Decorin

Serglycin

Syndecan

Perlecan

Versican
Mucoproteins has properties like of

Mucopolysaccharides.

Mucoproteins widely distributed in

Extracellular Matrix of connective

tissues ( Bone and Cartilage).

Mucoproteins provide structural

framework and mechanical

support to those tissues which

constitute them.

Mucopolysaccharidoses
Mucopolysaccharidoses are group

of inherited disorders related to

defective Mucopolysaccharide

metabolism.

Cause:
Impaired degradation of GAG's

by defective Lysosomal

enzymes.

Half life period of GAG's

is short.

3-10 days for most of the

GAG's.

120 days for Keratan ?SO4.
Biochemical Alterations :
No catabolism of GAG's.
Abnormal widespread intra

Lysosomal deposition of GAG's

in functional tissues affecting

their functions.

Excretion of MPS in Urine.

Mucopolysaccharidoses

Syndrome

Enzyme Defect

Accumulated GAG

Type

(Lysosomal)

I

Hurler's

- L Iduronidase

DS, HS

Syndrome

II

Hunters'

Iduronate Sulphatase

DS , HS

Syndrome

III

Sanfilippo's

Heparan Sulphatase

HS

Syndrome

IV

Morquio's

Galactosamine

KS, CS

Syndrome

Sulphatase.

V

Scheie's

L- Iduronidase

DS

Syndrome

VI

Maroteaux

N-

DS

Lamy

AcetylGalactosamine

Syndrome

-4-sulphatase.

VII

SLY's

- Glucuronidase.

DS, HS

IX

Naowicz

Hyaluronidase

HA

Syndrome
All Mucopolysaccharidoses

are of autosomal recessive

inheritance.

Hunter's Syndrome is of X

linked inheritance.

Consequences /Clinical Manifestations:

Lysosomal vesicles become swollen with

incomplete degraded GAG's in it.

Coarse facial features.
Thick skin, skeletal damage.
Corneal Opacity, Hearing loss.
Mental Retardation.
Hepatosplenomegaly.
Cardio pulmonary defects.
Growth deficiency and skeletal dysplasia.
Diagnosis:

Measuring concentration of

Lysosomal Hydrolases.

Detection of GAG in Urine.

Plant Heteropolysaccharides
Agar-Agar

Agar is obtained from red algae.(Sea weed)
Agar is formed of two main components,

Agarose and Agaropectin.

Agarose is a neutral galactose polymer, free

from sulfate.

Agaropectin is formed of galactose and

galacturonic acid units partially esterified

with sulfuric acid.

Uses of Agar

Preparation of bacteriological

culture media.

Emulsifier, thickener for ice

creams,puddings.

Laxative-for treatment of ulcers

and chronic constipation.
Pectin

Obtained from apple pomace and

inner portion of citrus rind.

Form viscous solutions in water.
Composed of Arabinose, Galactose

and Galactouronic acid.

Average molecular weight 100,000-

250,000.

Uses Of Pectin

Pectin is topically applied as a paste in

cases of burns and ulcers.

It acts as a detoxifying agent by

conjugation with toxins.

It is of great importance in treatment of

diarrhea and dysentery.

It is used as a gel and emulsion stabilizer

and in manufacture of jellies and jams.
Glycoproteins

Glycoproteins are conjugated

proteins

Where the prosthetic group,

branched or unbranched chain of

Oligosaccharide

Is linked to a protein backbone with
O-Glycosidic or N-Glycosidic

linkage.


O-Glycosidic/N-Glycosidic bonds

Oligosaccharide

Chain

Protein

Carbohydrate

content of

Glycoprotein is

less than 10%.


N-linked saccharides are

attached via the amide

nitrogens of Asparagine

residues .

O-linked saccharides are

attached to hydroxyl groups

of Serine, Threonine or

hydroxy Lysine .

N-linked Glycoproteins
O-linked Glycoproteins

Oligosaccharides have
different sequences of monosaccharide units
different sequences of glycosidic linkages.
different kinds of branching.

This imparts a very high degree of

diversity for Oligosaccharides and
their structure-function relationships
Varied glycosidic linkages in

Oligosaccharide chain of

Glycoproteins create enormous

variability required for

identifying different cells.

This variation is the basis for

the mechanism of cell-cell

recognition.

N-acetylneuraminate (N-acetylneuraminic acid,

also called sialic acid) is often found as a terminal

residue of oligosaccharide chains of glycoproteins.
Sialic acid imparts negative charge to

glycoproteins, because its carboxyl group tends to

dissociate a proton at physiological pH, as shown

here.
Significance of Oligosaccharide

chains in Glycoproteins :

Stabilizes the Proteins against

denaturation.

Protect Proteins from Proteolytic

degradation.

Enhances the solubility.
Serve as a recognition signals to

facilitate cell-cell interaction.

Glycoproteins of human body:

All plasma proteins are

Glycoproteins.

Structural protein Collagen of

bone is glycoprotein.

Enzymes- Ribonuclease-B,

Alkaline Phosphatase.
Hormonal receptors on cell

membranes.

Glycophorin is a major integral

membrane Glycoprotein of RBC's.

Lubricant Mucin.
Proteins-Transferrin and

Ceruloplasmin are Glycoproteins.

Glycoproteins and Glycolipids are

Glycocalyx of cell membranes.

Clotting factor-Prothrombin.
Hormones-Thyroglobulin,

Erythropoietin, TSH, HCG.

Immunoglobulin- IgG, IgA, IgD,

IgE, IgM.
Biomedical Importance's of

Carbohydrates.

Energy Aspects of

Carbohydrates/Carbohydrates

have dietary and calorific value

Carbohydrates serve as primary

source of energy, with calorific

value 4Cal/gm.

Carbohydrates of Dietary and

Calorific value

Starch (Predominant-Grains, Potatoes, Vegetables)
Glycogen (Non Veg diet)
Sucrose (Common table Sugar)
Lactose (Milk and Milk Products)
Maltose (Starch digestion, Malt)
Glucose (Glucon-D, Fruits)
Fructose (Fruits, Honey)
Reserve Store Capacity Of

Carbohydrates:

Dietary Carbohydrate (Glucose)

when free and excess in the body

get transformed to reserve store

forms Glycogen and Triacylglycerol

(Fat), which are utilized during

emergency conditions.

Non digestible Carbohydrate-

Cellulose serves as dietary

fiber :

Cellulose act as roughage and

prevents from constipation.

Cellulose has no calorific value

hence help in management of

obesity.
Carbohydrates as Dietary Fiber

Cellulose
Pectin
Lignin
Agar
Gum
Hemicellulose

Carbohydrates are components of

Mucoproteins

Glycoproteins
Glycolipids
Blood Group Substances
Structural and other functional

roles of Carbohydrates :

Mucoproteins present in connective

tissues provide structural and

mechanical support.

Hyaluronic acid in synovial fluid of

joints and vitreous humor of eye

serve as lubricant and shock

absorbent.

Heparin serves as natural

anticoagulant and prevents

intravascular coagulation.

Heparan sulfate present on cell

surfaces act as recognition elements on

cell membrane ,cell receptors and

helps in cell growth, cell adhesion,

and cell-cell communication.
Pentose sugars Ribose and

Deoxyribose are

components of Nucleotides

which build Nucleic acids ?

RNA and DNA and other

nucleotide coenzymes.

Diagnostic Value of Carbohydrate:

Fructosan Inulin, is used

to carry out:

Inulin Clearance Test,

which checks, Glomerular

Filtration Rate of kidney.
Therapeutic Value of

Carbohydrates:



Cardiac Glycosides Digoxin- used

to treat cardiac insufficiency.

Glycosides Ovabain and Phlorizin

- used in treatment of Diabetes

mellitus.

Glycosides Streptomycin

,Erythromycin used to treat

bacterial infections.

Mannitol- Serve as osmotic diuretic used

in treatment of Acute Renal Failure.

Lactulose -Relives Hyperammonaemia in

patients of Hepato Encephalopathy.

Dextran- Used as plasma substitute in

hemorrhagic cases to prevent

hypovoluemic shock.

Hyaluronan- Used to treat osteoarthritis.
Sr.No

Reducing Sugars

Non Reducing Sugars

1.

Reducing sugars possess free or potential

Non reducing sugars does not

aldehyde or ketone group in it's structure

possess free or potential
aldehyde or ketone group in it's
structure

2.

Reducing sugars show reducing property .It

Non Reducing Sugars does not

form an Enediol in alkaline medium which then

show reducing property.

reduces certain metallic ions of copper, bismuth

3.

Reducing Sugars answers following tests

Non Reducing Sugars answers

positively- Benedicts, Fehlings,

following tests negatively-

Nylanders, Osazone Tests

Benedicts, Fehlings, Nylanders,
Osazone Tests

4.

Reducing sugars exhibit Mutarotation

Non Reducing sugars does not
show Mutarotation

5.

Examples of Reducing Sugars -

Examples of Non Reducing Sugars

All Monosaccharide's are Reducing Sugars- ex

or

Ribose, Glucose, Fructose etc

Non reducing Disaccharide-

Reducing Disaccharides-Lactose, Maltose

Sucrose, Trehalose.

Sr. No

Amylose

Amylopectin

1.

Starch granule contains 15-20% of

Starch granule has 80-85% of

Amylose.

Amylopectin.

2.

Amylose is soluble and present in

Amylopectin is insoluble part present at

inner core of starch granule.

periphery of starch granule.

3.

Amylose is a linear, unbranched

Amylopectin is a branched structure,

structure composed of 200-1000

composed of more than 1000 D

D Glucose units repeatedly linked by Glucose units linked by (1-4)
(1-4) glycosidic bonds

glycosidic bond in linear and (1-6)
glycosidic bond at branching point,
which appears after every 25-30
Glucose residues.

4.

Molecular weight of Amylose is

Molecular weight of Amylopectin is 1

400000

million .

5.

Amylose gives blue color with Iodine Amylopectin gives reddish violet color
test.

with Iodine test.
Sr. No

Starch

Glycogen

Starch is Plant Homopolysaccharide. Glycogen is animal Homopolysaccharide

1.
2.

Starch is composed of Amylose

Glycogen is highly branched structure

(Linear)&Amylopectin (Branched)

with branching points appearing after
every 8-10 Glucose residues.

3.

Starch is composed of 4000-7000

Glycogen is composed of 6000-30,000

Glucose units.

Glucose units.

4.

Starch is a storage form of Glucose Glycogen is storage form of Glucose and
and reserve food material in plants.

reserve form of energy in animals and
human beings.

5.

Starch is stored in roots, tubers,

Glycogen is stored in Liver and Muscles

seeds, raw fruits of plants.

of animal and human body.

6.

Starch serves as predominant dietary Glycogen is dietary form of Carbohydrate
Carbohydrate form in Veg and

only in Non-Veg eaters.

Nonveg eaters.

7.

Starch with Iodine test gives deep

Glycogen with Iodine test gives deep red

Blue color.

color.

Sr.No

Starch

Cellulose

Starch is a Glucosan composed of

Cellulose is a Glucosan composed of

1.

DGlucose units, repeatedly linked DGlucose units ,repeatedly linked by
by (1-4) glycosidic bonds in linear (1-4) glycosidic bonds.
and (1-6) glycosidic bonds at
branching point.

2.

Starch present in plants serve as

Cellulose present in plant cell wall

storage form of Glucose and reserve provides structural frame work to plants.
food material.

3.

Dietary Starch is digested in human Dietary Cellulose is not digested in
GIT by enzyme Amylase.

human GIT due to absence of enzyme
Cellulase.

4.

Starch has dietary and calorific value. Cellulose has no calorific value but serve

as dietary fiber.
Sr.No

Dextrin

Dextran

1.

Dextrin is plant

Dextran is bacterial

Homopolysaccharide

Homopolysaccharide.

2.

Dextrin is an intermediary

Dextran is a Glucosan obtained

hydrolytic product of Starch from Sucrose solution incubated
digestion.

with Leuconostoc mesenteroides.

3.

Structure of Dextrin contains Structure of Dextran contains (1-
(1-4) & (1-6) glycosidic 3),
bonds.

(1-4) & (1-6) glycosidic bonds.

4.

Dextrin solution is used in

Dextran solution is used as plasma

commercially prepared infant volume expander in relieving
feedings and mucilage for

hypovoluemic shock in cases of

pasting stamps.

hemorrhage.

QUESTIONS
Q.1.Define carbohydrates.
Enumerate the biomedically

important Carbohydrates.

Q.2.Classify and sub classify

Carbohydrates with terms and suitable

examples.

Q.3. Simple Sugars /Monosaccharides

Q.4. Define stereoisomerism.

Enumerate the stereoisomers of

Glucose.

Q.5. D & L Glucose
Q.6. Anomers
Q.7. Epimers
Q.8. What is optical activity? Give

its type.

Q.9. Mutarotaion
Q.10. Chemical Reactions of Glucose

/Reactions of Monosaccharides.

Q.11. Write 8 derivatives of

Monosaccharides and their

importance.

Q.12. Glycosides and its

importance.

Q.13. Osazones Reaction. Draw the

structures of Glucosazone,

Fructosazone, Lactosazone &

Maltosazone.

Q.14. Explain why Glucosazone &

Fructosazone show same shape.
Q.15. Disaccharides (Definition,

Types, Components, Glycosidic bonds,

Sources ,Biomedical Importances).

Q.16. Invert sugar,
Q.17. Lobry- de- Bruyn- Von

Ekenstein transformation

Q.18. Haworth and Fischer's projection of

Glucose.

Q.19. Why sucrose is a non-reducing

sugar?

Q.20. Homoglycans /

Homopolysaccharides

Q.21. Glycosaminoglycans /Acid

Mucopolysaccharides (structure &

function)/Animal Heteropolysaccharides

Q.22. Inulin and its importance.
Q.23. Differences between

Dextrin and Dextran.

Q.24. Cellulose & its

importance.

Q.25. Distinguish between

reducing & non-reducing sugars.

Q.26. Write the components and

glycosidic linkages involved in following

carbohydrates.

Sucrose
Maltose
Lactose
Glycogen
Cellulose
Amylose
Amylopectin
Q.27. Mucoproteins.
Q.29. Biomedical Importance

of carbohydrates.

Q.30. Mucic acid test.
Q.31. Test's to check the

present of reducing sugars.

Q.32. Glycosidic bonds.

Q.33. Glycoproteins of human body.
Q.34. Differentiate between Starch

and Cellulose.

Q.35 Differentiate between Starch

and Glycogen.

Q.36 Mucopolysaccharidoses.
Q.37 Diagnostic and therapeutic

uses of Carbohydrates.


THANK YOU

This post was last modified on 05 April 2022