Carbohydrates can be classified as monosaccharides, disaccharides, oligosaccharides, or polysaccharides. Monosaccharides include glucose, fructose, and galactose. Disaccharides are two monosaccharides joined together, such as sucrose from glucose and fructose or lactose from glucose and galactose. Polysaccharides are long chains of monosaccharides and include starch, cellulose, and glycogen. Starch is used by plants for energy storage while glycogen serves the same function for animals. Cellulose provides structure to plant cell walls.

1. Carbohydrates

2. CARBOHYDRATES
• (glycans) have the following basic composition:
I
(CH2O)n or H - C - OH
I

3. • CARBOHYDRATE is defined as polyhydroxy aldehyde or
ketones subunits.
• It contains aldehyde :
• H-C=O
• And Keto :
• C=O
• These are also called sacchrides.
• It is a group of organic compounds having carbon, oxygen and
hydrogen thus called “Hydrated carbons” .

4. SOURCES:
• Green plants Grains
• Milk Beans
• Fruits Sugar canes

5. TYPES OF CARBOHYDRATES:
 Monosaccharides - simple sugars with multiple OH groups.
Based on number of carbons (3, 4, 5, 6), a monosaccharide is a
triose, tetrose, pentose or hexose.
 Disaccharides - 2 monosaccharides covalently linked.
 Oligosaccharides - a few monosaccharides covalently linked.
 Polysaccharides - polymers consisting of chains of
monosaccharide or disaccharide units.

7. MONOSACCHRIDES:
• These are called “Simple Sugars”, because they can not be
hydrolysed further into simple sugars.
• Their general formula is “Cn H2n On .
• They are white crystalline solids with sweet taste and soluble
in water.
• They are present in various fruits and vegetables.

8. • Chemically these are polyhydroxy aldehyde or ketones.
• These are found naturally from 3 to 7 C-atoms.
• These can be:
• Triose (3C)
• Tetrose (4C)
• Pentose (5C)
• Hexose (6C).

9. Aldoses (e.g., glucose) have an
aldehyde group at one end
Ketoses (e.g., fructose) have a
keto group, usually at C2.
C
C OHH
C HHO
C OHH
C OHH
CH2OH
D-glucose
OH
C HHO
C OHH
C OHH
CH2OH
CH2OH
C O
D-fructose

10. EXAMPLES OF MONOSACCHRIDES:
• GLUCOSE:
• Basic sub-unit of other larger carbohydrate molecules.
• Molecular formula C6H12O6.
• Make ring and linear structure.
• Two types :
• Alpha glucose; having OH group downside of the ring.
• Beta glucose; having OH group upside of the ring.

14. FRUCTOSE:
• Also known as "Fruit Sugar“.
• It is a simple ketonic monosaccharide found in many plants.
• In combined state with Glucose , it gives a Disacchride
“sucrose”.
• Glucose +fructose= sucrose.

15. Structure of fructose:

16. Galactose :
• Also called Milk sugar.
• It is a monosacchride with less sweet in test than glucose.
• In combined state with Glucose it gives a Disacchride
“lactose”.

17. Structure of Galactose

18. Disacchrides :
• A disaccharide is a sugar (a carbohydrate) composed of
two monosaccharides and water molecule is removed.
• These are soluble in water.
• General formula is C12H22O11.
• These are crystalline , less sweet than monossacrides.

20. Polysachrides :
• Polysaccharides are complex carbohydrates, composed of 10
to up to several thousand monosaccharides arranged in chains.
• The most common monosaccharide in polysaccharides
are glucose, fructose, galactose and mannose.

21. • These are tasteless , and sparingly soluble in water.
• These are usually branched and have high molecular weight.
• It can be categorised into:
• Structural polysacchride : includes cellulose and chitin.
• Functional polysacchride : includes glycogen and starch.

22. Starch:
• These are found in white powder as dry state.
• Tasteless and odorless.
• Insoluble in water.
• Made up of the lareg chain of alpha-glucose.
• Generall formula is (C6H10O5)n.

25. • It can be classified into:
• Amylose :
These have unbranched chain of glucose molecule.
Soluble in hot water.
• Amylopectin:
These have branched chain of glucose molecule.
Insoluble in water.

26. H O
OH
H
OHH
OH
CH2OH
H
O H
H
OHH
OH
CH2OH
H
O
HH H O
O
H
OHH
OH
CH2OH
H
H H O
H
OHH
OH
CH2OH
H
OH
HH O
O
H
OHH
OH
CH2OH
H
O
H
1
6
5
4
3
1
2
amylose

27. H O
OH
H
OHH
OH
CH2OH
H
O H
H
OHH
OH
CH2OH
H
O
HH H O
O
H
OHH
OH
CH2
H
H H O
H
OHH
OH
CH2OH
H
OH
HH O
O
H
OHH
OH
CH2OH
H
O
H
O
1 4
6
H O
H
OHH
OH
CH2OH
H
H H O
H
OHH
OH
CH2OH
H
H
O
1
OH
3
4
5
2
amylopectin

28. Functions of starch:
• Dietry function of starch is to convert glucose into energy for
body and brain.
• In plants they store glucose.
• Chemically modified and unmodified starch used for
papermaking.
• Vegetable starch mix into into water used for laundery
purpose.

29. Cellulose:
• It is a polysacchride made up of the linear chain of several
glucose molecules.
• Mainly it consists of beta-glucose.
• It has no taste and no odor.
• Highly insoluble in water.
• Digestable by herbivores.
• Generall formula is (C6H10O5)n.

30. Chemical structure of cellulose:

32. Functions of cellulose:
• Provide shape to plant cell wall.
• Produces lignin which makes the wood of tree so strong.
• Powdered cellulose are used as inactive fillers in drug tablets.
• Used for textile purpose made from cotton and linen.

33. GLYCOGEN:
• It is also called animal starch.
• It is a multibranched polyscchride.
• In dry state ,present in white powder.
• Insoluble in water.
• Found in the form of granules in the cytosol in many cell
types.
• Generall formula is C24H42O21.

34. • Made up of the alpha-glucose molecules,
• Present in liver cells with 8%.
• Present in muscles with 1%,
• In kidney low amount is found.

35. H O
OH
H
OHH
OH
CH2OH
H
O H
H
OHH
OH
CH2OH
H
O
HH H O
O
H
OHH
OH
CH2
H
H H O
H
OHH
OH
CH2OH
H
OH
HH O
O
H
OHH
OH
CH2OH
H
O
H
O
1 4
6
H O
H
OHH
OH
CH2OH
H
H H O
H
OHH
OH
CH2OH
H
H
O
1
OH
3
4
5
2
glycogen

37. Functions of glycogen:
• The main function of glycogen is as a secondary long-term
energy-storage molecule.
• In liver : regulates to maintain blood glucose level.
• In muscles : provide energy to muscles .

38. Chitin :
• A long-chain polymer of an N-acetylglucosamine.
• Chitin is a modified polysaccharide that contains nitrogen; it
is synthesized from units of N-acetyl-D-glucosamine.
• Found in the cell walls of certain fungi and algae.
• Formula = (C8H13O5N)n

40. Functions of chitin:
• It makes the cell wall of fungi and algae.
• Chitin is a good inducer of defense mechanisms in plants.
• It accelerates healing of wood in humans.
• Chemically modified chitin used in food processing and as an
additive to thicken and stablize food.