CARBOHYDRATE

Today topic is carbohydrate.

In simple words carbohydrate is a compound that contain carbon, oxygen and hydrogen.

Definition of carbohydrate

Carbohydrate define as chemical in neutral compound of carbon, Oxygen and hydrogen.

It also define as polyhydroxy, aldehydes or ketone compounds, which produce them on hydrolysis.

Other definition, carbohydrates are aldehyde or ketone derivatives of polyhydric alcohols or any substance derived from them.

Dietary source

Bread

Beans

Milk

Popcorn see

Potatoes

Cookies

Sugar

Fruits like apple and banana

Some specific functions of carbohydrate

1) it's a source of energy.

2) it's a part of structure of cell membrane.

3) precursor for many organic compounds like fats and amino acids.

4) it helps in the cellular functions such as growth and fertilization.

5) it serves as the storage form of energy.

Classification

Sometimes carbohydrate classified into four groups, namely as monosaccharide, disaccharide, and oligosaccharides and polysaccharide s.

But most of the people classify carbohydrate into three groups, such as

1) Monosaccharide

2) Oligosaccharide

3) Polysaccharide

Monosaccharide

These are simple group of carbohydrate and referred as simple sugar. For example, glucose, fructose.

Oligosaccharide

They are made up of two to 10 units of monosaccharide molecules. For example, raffinose.

Oligosaccharide divide into disaccharide, trisaccharide and soon.

Examples of disaccharide are lactose, maltose and sucrose.

Polysaccharide

Made up of more than 10 units of monosaccharide, which have high molecular weight. They are tasteless and non sugar. Examples are starch, glycogen, cellulose, etc.

Further polysaccharide into two groups.

1) Homo-polysaccharide

e.g., starch and glycogen.

2) Hetero-polysaccharide

e.g., heparin.

Digestion of carbohydrate

Digestion of carbohydrate complete in three steps.

First, digestion start during the chewing of food in mouth due to the presence of salivary alpha-amylase enzyme in saliva.

Secondly, breakdown of food take place in stomach in the presence of hydrochloric acid (HCl).

Finally, further digestion of small molecules of carbohydrate take place in small intestine due to the presence of pancreatic alpha-amylase enzyme.

One molecule of glucose break into 38 ATP due to the oxidation of glucose.

Absorption of carbohydrate

1) digested food reach in blood stream through Alimentary canal.

2) monosaccharide is absorbed in small intestine.

3) sodium glucose transport protein in membrane help to absorb glucose and glactose.

4) fructose absorb is converted to glucose inside the cell.

Mechanisms of absorption

1) passive diffusion

2) facilitated diffusion

3) active transport

Metabolism of carbohydrate

There are many pathways of metabolism of carbohydrate.

1) Glycolysis

In this, glucose converted to pyruvate and lactate. It takes place in RBC due to the help of enolase enzyme.

2) Citric acid cycle

Also known as KREBS CYCLE.

It is the final oxidative pathway for carbohydrate, fats and protein through Acetyl CoA.

3) Gluconeogenesis

In this, synthesis of glucose from non-carbohydrate precursors. e.g., amino acids, and glycerol.

4) Glycogenesis

Formation of glycogen from glucose.

5) Glycogenolysis

Breakdown of glycogen to glucose.

6) Hexose monophosphate shunt (HMP SHUNT)

This pathway is an alternative to Glycolysis and Kreb cycle for the oxidation of glucose.

Other pathways

1) Uronic acid pathway

2) Galactose metabolism pathway

3) Fructose metabolism pathway

4) Amino sugar metabolism pathway

In next topic I'm going to discuss protein. For any correction and suggestion please comment. I will try to perform better.

This topic is published by

Abhishek Ranjan.

Gmail - photostannu@gmail.com