Carbohydrates
Carbohydrates are a major source of energy in our diet. Carbohydrates provide the energy which we need in our daily life, to do our day to day activities, to walk, to run, to do exercises etc. Carbohydrates provide the energy actually used. ___ So it'll be worth your while to get aware more about carbohydrates.

Importance of Carbohydrates
1.Carbohydrates provide energy for your survival
As mentioned earlier carbohydrates are the major source of energy in the diet. Your body must maintain a good supply of energy for survival.
This energy is used for various essential activities. Some examples are given below.

1.Synthesis of substances for growth and repair.
Ex:-Protein synthesis

2.Active transport of substances into and out of cells against diffusion gradients.

3. Phagocytosis

4. Electrical transmission of nerve impulses

5. Mechanical contraction of muscles and beating of cilia and flagella.

6. Heat energy released from respiration, used to maintain a constant body temperature in your body.


2. Carbohydrates are building blocks for more complex molecules
Carbohydrates contribute to build more complex and biological molecules in your body such as Nucleic acids, Nucleotides and Glycogen.

Principle Sources Of Carbohydrates

Sugar and Starch are rich of Carbohydrates.

1. Cereal
Ex:- Barley, Buckwheat, Corn, Maize, Millet, Oats, Rice, Rye, Wheat

2. Fruits
3. Vegetables
4. Animal Liver


Chemistry Of Carbohydrates
Carbohydrates are substances containing Carbon, Hydrogen and Oxygen.
General formula is Cx(H2O)y
All are aldehydes or ketones.
All contain several hydroxyl groups.

Carbohydrates are divided into three main classes.
1. Monosaccharides
2. Disaccharides
3. Polysaccharides
Monosaccharides
Monosaccharides are single sugar units.
All are reducing sugars. (That means these compounds can reduce the substances, which can be easily reduced.)
General formula (CH2O)n where n =3 to 9
Small molecules
Sweet
Readily soluble in water
Crystalline

Monosaccharides can be classified into two groups according to the major functioning group of them.
1. Aldo Sugar
2. Keto Sugar

In monosaccharides all the carbon atoms except one have a hydroxyl group attached. If the remaining carbon atom is a part of an aldehyde group, the monosaccharide is called an aldose/aldo sugar.
Ex:-Glucose
If it is a art of Keto group it is called a Keto sugar.
Ex:-Fructose

In general aldoses are more common than ketoses.

Monosaccharides are more commonly found in ring forms than open chains.

These substances are classified according to the number of carbon atoms.
Number of Carbon atoms
Name
Example
Main Functions
3
Trioses
glyceraldehyde
dyhydroxoacetone
Interemediates in respiration and photosynthesis
4
Tetroses
erythrose

5
Pentoses
ribose
ribulose
synthesis of nucleic acids, Co-enzymes, ATP,

6
Hexoses
glucose, galactose, fructose
Source of energy when oxidised in respiration.
Synthesis of disaccharides and polysaccharides.
7
Heptoses
heptulose


Glucose- The most common respiratory substrate in living organisms. .






Disaccharides
Disaccharides are formed when weo monosaccharides usually hexoses combine by means of a chemical reaction known as a condensation.
Some are reducing sugars.
Ex:- Moltose, Galactose

Some are non-reducing sugars.
Ex:-Sucrose

All are reducing sugars.
General formula Cx(H2O)x-1
Small molecules
Sweet
Readily soluble in water
Crystalline