1. CARBOHYDRATES
HIMA HARIDASAN

2. INTRODUCTION
 Most abundant biomolecule on earth
 Def : polyhydroxy aldehydes or ketones
 G.F. : (CH2O) n
Composition : C: H :O – 1:2:1

3. FUNCTIONS
 Organic matter
 Energy stores, fuels, & metabolic intermediates
 Ribose & deoxyribose
 Structural components
 Glycolipids &glycoproteins
 Industries
 Excess Fat
 Can’t be further hydrolysed

4. CLASSIFICATION
SIMPLE COMPLEX
MONOSACCHARIDES
OLIGOSSACHARIDES
POLYSACCHARIDES
ALDOSE
KETOSE
TRIOSE
TETROSE
PENTOSE
HEXOSE
HEPTOSE
•1 / 2 monomeric
units
•Sweet
•Monomer
polymer
•Starchy

5. MONOSACCHARIDES
Mono = 1
Single polyhydroxy aldehyde or
ketone.
Literally- C hydrate
Colorless
Crystalline
Solubility – H2O

6. NO.OF
C
ATOMS
CLASSES ALDOSE KETOSE
3 Triose Glyceraldehyde Dihydroxyacetone
4 Tetrose Erythrose Erythrulose
5 Pentose Ribose Ribulose
6 Hexose Glucose Fructose
7 Heptose Glucoheptose Sedoheptose

7. FISCHER’S PROJECTION
 Herman Emil Fischer
 2D representation of a 3D organic molecule by projection
 Bonds :-
Horizontal - viewers
Vertical - viewers
 Use : to differentiate btw L- and D- molecules

8. Features:-
 Can’t be rotated by 90° or 270° in the plane of the
page or the screen, as the orientation of bonds
relative to one another can change, converting a
molecule to its enantiomer.
 Rotation of 180° doesn't change the molecule's
representation.
( Enantiomer: one of two stereoisomers that
are mirror images of each other; non-superposable)

9. HAWORTH PROJECTION
 Syn: Norman projection; pyranose projection
 Sir Norman Haworth
 In aqs soln.
 Cyclic/ring structure of monosaccharide
 3D

10.  Result of: general reaction btw aldehydes or ketones
with alcohols to form derivatives called hemiacetals
or hemiketals.

11. Characteristics:_
 C - implicit type; C1- anomeric carbon.
 H - implicit
 Thicker/Thinner line indicates atoms that are closer/far
to the observer.
 The groups below the plane of the ring in Haworth
projections = groups on the right-hand side of a Fischer
projection.

12. GLYCERALDEHYDE

13. FISCHER’S
PROJECTION
HAWORTH
PROJECTION
GLUCOSE

14. D- FRUCTOSE
FISCHER’S PROJECTION HAWORTH PROJECTION

15. D-MANNOSE
FISCHER’S PROJECTION HAWORTH PROJECTION

16. D- GALACTOSE
FISCHER’S PROJECTION HAWORTH PROJECTION

17. OLIGOSACCHARIDES
 2-10 monosaccharide units linked by glycosidic linkage
 Oligo = a few
 Associated with:-
1) Proteins - glycoproteins
2) Lipids - glycolipids
 Varities seen more in plant kingdom than animal
kingdom
 Most abuntant- dissacharides

18. OLIGOSACCHARIDE CLASSIFICATION BASED
ON THE NO.OF MONOMERIC UNITS
CLASS
NO.OF
MONOMERS EXAMPLES
DISACCHARIDE 2 LACTOSE
TRISACCHARIDE 3 RAFFINOSE
TETRASACCHARIDE 4 STACHYOSE
PENTASACCHARIDE 5 VERBASCOSE

19. DISACCHARIDES
Syn: biose
 2 monosaccharides covalently linked
 Linkage – glycosidic
 Result of - condensation reaction (the
elimination of a small molecule, like H2O,
from the functional groups only)
 Solubility - H2O

20. DISACCHARIDES
REDUCING
MALTOSE
ISOMALTOSE
LACTOSE
CELLOBIOSE
NON-REDUCING
SUCROSE
TREHALOSE

21. SUCROSE
 Syn: cane sugar
 Sweetning agent
 Source: cane & beet sugar, pineapple,sorghum, carrot
 Designation: α-D-glucopyranosido-β-D-fructofuranoside
 Found as such in most photosynthetic plant
 Sucrose deficiency- malabsorption leads to diarrhea &
flatulence
 D.E: sucrase or invertase

22. Sucrase Action:-

23. TREHALOSE
 Dsgn: 1-(α -D-glucopyranosido)- α -D-glucopyranoside
 Source: ocoon of Trehela, hemolymph of some insects &
fungi including yeast
 Sweetning agent
 D.E.: trehalase
Trehalose Trehalase
2-D-Glucose

24. MALTOSE
 Syn: malt sugar
 Designation: 4-(α -D-glucopyranosido)-D-glucopyranose
 Doesn’t occur naturally
 Usually obtained in β form
 Source: starch hydrolysis, germinating cereals, malt
 Intermediate of starch
 D.E.: Maltase

26. LACTOSE
Syn: milk sugar
 Reducing
 Designation: 4-(β -D-galactopyranosido)-
D-glucopyranose
Usually obtained in β form
 Constitute 5% in milk
 Exclusive cbh source for breast fed infants

27.  D.E: lactase
 Lactase action:-
 Lactose intolerance: lactase deficiency
leads to diarrhea & flatulence

28. CELLOBIOSE
 Formed on cellulose degradation
 On hydrolysis gives β -D-glucose
 Dsgn: 4-(β -D-glucopyranosido)-D-glucopyranose
 Source: enzymatic or acidic hydrolysis of cellulose and
cellulose rich materials such as cotton, jute, or paper.
ISOMALTOSE
 Dsgn: 6-(α -D-glucopyranosido)-D-glucopyranose
 Produced when high maltose syrup is treated with the
enzyme transglucosidase

30. POLYSACCHARIDE
 Poly = many
 >10 monosaccharide units
 Syn: glycans
 Classification – different ways on the basis of:-
1. Structure : linear & branched
2. Homogenity btw monomers: homo & hetero
3. Function: muco, storage & structural
 Linear polysaccharides: line/ chain. Eg- cellulose.
 Branched polysaccharides: linear chains with units arising
from different C atoms, branched. Eg- starch, glycogen.

31.  Storage polysaccharides:-
1. acts as reserve food
2. Hydrolysed to sugars required for respiration &
biosynthesis
3. Eg- starch, glycogen, inulin.
4. Syn: nutrient polysaccharides
 Structural polysaccharides:-
1. Fibrous
2. Cell walls of plants, fungi, & exoskeleton of arthropods

32. Mucopolysaccharides
1. Syn: GAG
2. Heteroglycans
3. Slime & mucilage producing.
4. Composition- repeating units of sugar derivatives
namely, amino sugars & uronic acids.
5. General groups present- acetylated amino groups,
sulphate & carbonyl groups
6. Acid mucopolysaccharides - Sulphate & carbonyl
groups contributes to acidity
7. Eg- heparin, hyalouronic acid

33.  Homopolysaccharide
1. Homoglycans
2. Eg- Starch, glycogen,cellulose,chitin,xylan
 Heteropolysaccharide
1. Heteroglycans
2. Monomers- non-identical
3. Complex
4. Eg: hyaluronic acids, heparin, agar, chondroitin
sulphate, keratan sulphate, dermatan sulphate, gum
arabic, pectin & so more.

34. STARCH
 Syn: amylum
 Widely distributed in plant kingdom
 Components- amylose & amylopectin
 D.E.:-
1. Amylase - maltose, glucose; Site of action- α(1 4) glycosidic bonds
2. Sucrase – G & F; α(1 4) glycosidic bonds
3. Α-glucosidase- removes 1 unit at a time from oligosaccharide
4. Α-dextrinase – debranching enzyme; α (1 4) & α(1 6) .

35. FEATURE AMYLOSE AMYLOPECTIN
Content in starch 15% - 20% 80% - 85%
Branching Absent Present [α(1,6) g.l. at brancing
points]
Linkage α-1,4 α-1,4 ; α-1,6
No.of G units 200-1000 20-30
Water solubility Present Absent
Color reaction with
iodine gives
Blue Reddish-violet

36. CH2OH
CH2OH
H
OH
H O
OH
H
H
OH
H OH
CH2
CH2OH
H
OH
H H O H
H O
H
CH2OH
H
OH
H OH
O
O
H
H
OH
H OH
CH2OH
CH2OH
H H O
H O H
H
H
OH
H OH
OH
O
H
H
OH
H OH
O
H
O
1 4
6
H O
H
H OH
H H O
H
H OH
H
O
1
OH
3
4
5
2
amylopectin

37. GLYCOGEN
 Animal starch
 Stored in liver & muscles
 Source- plants that lack chlorophyll, yeast, fungi, etc.
 D.E. : glycogen phosphorylaseand amylase
 Monomers- α & β G units; (1,4)g.l.
 Glycogenolysis
 With I2 – red
 Branching occurs after 12 G units

38. CH2OH
CH2OH
H
OH
H O
OH
H
H
OH
H OH
CH2
CH2OH
H
OH
H H O H
H O
H
CH2OH
H
OH
H OH
O
O
H
H
OH
H OH
CH2OH
CH2OH
H O H
H H O
H
H
OH
H OH
OH
O
H
H
OH
H OH
O
H
O
1 4
6
H O
H
H OH
H H O
H
H OH
H
O
1
OH
3
4
5
2
glycogen