Carbohydrates are a major source of energy and can be classified as simple or complex depending on their chemical structure. Simple carbohydrates like monosaccharides (glucose, fructose, galactose) and disaccharides (sucrose, maltose, lactose) are small molecules that are quickly absorbed, while complex carbohydrates like starches and fibers are large molecules that are absorbed slowly. Carbohydrates serve many functions including energy storage, structural support, and promoting healthy digestion. Both insufficient and excessive carbohydrate intake can negatively impact health.

1. CARBOHYDRATEs

2. A component of food
that supplies energy
to the body.
Carbohydrate
contain Carbon,
Hydrogen and
Oxygen.

3. Depends on the chemical structure of the
food:
Simple carbohydrates include mono and
disaccharides. These are small molecules
which dissolve in water and are absorbed
very quickly in the body.
Complex carbohydrates include
polysaccharides. Starches and dietary fibres
are very large, complex molecules and
absorbed slowly.

6. Carbohydrates are classified
in to three major classes on
the basis of behavior on
hydrolysis:-
1) Monosaccharide
2) Disaccharides
3) Polysaccharides

7. Are the most basic units of
carbohydrates. They are the
simplest form of sugar and are
usually colorless and water
soluble.
Examples:-
Glucose
Fructose
Galactose

8. Also known as dextrose, grape sugar,
or corn sugar.
It is found in sweet fruits such as
grapes, and oranges and in some
vegetable such as sweet corn and
carrots.

9. Fruit sugar is highly soluble sugar.
 It is found in honey, ripe fruits and
some vegetables.
In humans, fructose produce during
the hydrolysis of sucrose.

10. Galactose is not found free in
nature.
Its only source is lactose which on
hydrolysis yields glucose and
galactose.

11. Two sugars linked together to form a
chain. They are water soluble. It
convert into simplest form of sugar
by acid, enzymes and heat.
Examples:-
1) Sucrose
2) Maltose
3) Lactose

12. Is found in cane or beet sugar, and
maple sugar.
Many fruits and some vegetables
contain small amounts of sucrose.
SUCROSE------GLUCOSE + FRUCTOSE

13. Also known as malt sugar and is
found in cereals.
It is intermediate product in the
hydrolysis of starch and
fermentation of grain and is present
in beer.
In corn sugar 4% maltose is present.
MALTOSE------GLUCOSE + GLUCOSE

14. Lactose or milk sugar is
disaccharides.
The enzyme lactase is needed to
digest lactose.
Cow’s Milk  6.8g/100 ml.
Mother’s Milk  4.8g/100 ml.
LACTOSE ----- GLUCOSE + GALACTOSE

15. Carbohydrates made up of long
chain of sugars are called
polysaccharides (poly = many).
They are very large, complex
molecules and insoluble in water.
It constructed by joining
monosaccharide units together by
glycosidic bonds.

16. Storage,
Structural

17. Glycogen
Also known as animal
starch.
A polysaccharide that
humans and animals store
in the liver and muscles.

18. Starch
Starch is the main storage
polysaccharides of plants.
It is found in cereal grains, legumes and
in tubers.
Starches are not water soluble.
CEREALS  65-85 %
SEEDS & ROOTS  19-35 %
FRUITS % VEGETABLES  2-10 %

19. These are glucose polymers made
up of Amylose and Amylopectin.
Amylose molecule chains are
linear (long but no branches)
while Amylopectin molecules
are long and branch out - some
Amylopectin molecules are
made of several thousand
glucose units.

20. Cellulose
Cellulose is composed of thousands
of glucose molecules.
Cellulose are found in stalks and
leaves of vegetables and outer
covering of seeds.

21. The structural parts of plants
which are not digested by
enzymes in the human intestinal
tract are known as dietary fibres.

22. Soluble Fibres
Viscous plants fibres are
soluble in water.
These include pectin, and
gums.
Found in fruits, oats, legumes
and beans.

23. Insoluble Fibres
Structural parts of the plants cell
wall( cellulose, hemicelluloses)
which are not soluble in water.
Found in wheat, seeds, nuts and
vegetables.

24. Ability to absorb water
Feeling of fullness
Insoluble fibres needs chewing and may
improve mastication of food
These indigestible substances serve a
useful purpose in helping the
elimination of intestinal wastes
They stimulates the peristaltic
movements of the gastrointestinal tract
by adding bulk

25. Source of Energy: The primary
function of carbohydrate in the
body is to supply energy. Each
gram of carbohydrate, as starch
or sugar, provides 4 kcal/g.
Role in liver :- Liver rich in
glycogen and is more resistant to
certain poisons such as carbon,
alcohol and toxins of bacteria.

26. Role in Muscle
Carbohydrate are the major source of
energy for muscular work.
During muscular contraction, glycogen is
broken down to lactic acid through
glycolysis.
Lactic acid oxidized to pyruvic acid then
to Acetyl CoA which is oxidized to
carbon dioxide and water, thus
producing energy for muscular work.

27. Protein Sparing Action
Oxidation of fats
Conversion of fat
Reserve fuel supply
To prevent dehydration
Indispensability for nervous system
Source of energy in heart muscles
Promote growth of desirable bacteria
Contribution of dietary fibres
Add flavor to the diet

28. Eating too many Carbohydrate leads to
weight gain.
Risk of obesity
Atherosclerosis
Dental caries
Other conditions
Excess calories from carbohydrate are
stored as fat, which contribute to obesity
and its risk including Diabetes, heart
disease, hyperglycemia.

29.  Lack of energy
 Physical fatigue
 Dizziness
 Headaches
 Weakness
 Mental Fatigue
 Nutrients deficiencies
 Nausea
 Diarrhea
 Constipation
 Sleep disturbances
 Malnutrition
• Hypoglycemia: Low blood sugar is most
common in people who have diabetes.

30. CARBOHYDRATES MAIN FOOD SOURCES
1. Monosaccharides
Glucose Fruits, Honey, Corn Syrup
Fructose Fruits, Honey
Galactose Milk
2. Disaccharides
Sucrose Cane and Beet sugar
Lactose Milk and Milk products
Maltose Malt products
3. Polysaccharides
Starch and Dextrins Grains , Legumes
Glycogen Meat
Cellulose Outer covering of seeds, Leaves of vegetables
Pectin Fruits

38. • Maltose, sucrose and lactose are
hydrolyzed by maltase, sucrase
and lactase of intestinal juice for
conversion to simplest sugar
(glucose, fructose, galactose).
Digestion in Small Intestine

39. • Carbohydrates, not digested in the small
intestine including cellulose, pectin (foods
such as potatoes, beans, wheat flour and
starch).
• They are digested and converted in variable
such as lactic acid, butyric acid, acidic acid,
carbon dioxide, and hydrogen when they
reach the large intestine.
Digestion in Large Intestine