Information on Carbohydrates

What are Carbohydrates?

The Carbohydrates are naturally occurring organic substances. They are present in both plants and animals. The dry mass of plant is composed of 50-80% of the polymeric Carbohydrate cellulose. Carbohydrate is formed in the plants during photosynthesis from Carbon dioxide and water. Animals do not synthesis Carbohydrates but they rely on plants for their supply.

Carbohydrates are mainly compound of Carbon (C), Hydrogen (H) and Oxygen (O). The name “Carbohydrate” arose from the mistaken belief that the substances of this kind were hydrates of Carbon. Details : Chemical formula of Carbohydrates

Physical Properties of Carbohydrates

  • In general, Carbohydrates are white solids, sparingly soluble in organic solvents and are soluble in water.
  • Many Carbohydrates of low molecular masses have a sweet taste.
  • Carbohydrates are often referred to as saccharides (derived from Latin word Saccharum meaning sugar) because of sweet taste of simpler members of the class.

Functions Of Carbohydrates

Carbohydrate functions as a Bio Fuel, a storage food, a framework in body, Anticoagulant, Antigens, and Hormones and provides raw material for industry. Read in Detail : Functions of Carbohydrates.

Types of Carbohydrates

The Carbohydrates are divided into three major classes depending upon whether or not they undergo hydrolysis. They are further divided into Monosaccharides, Oligosaccharides and Polysaccharides.

Monosaccharides are commonly known as simple sugars. They cannot be broken down into more simple sugar with hydrolysis.

Oligosaccharides are complex Carbohydrates which undergo hydrolysis to yield 2 – 10 molecules of Monosaccharides. Oligosaccharides are further divided into Disaccharides, Trisaccharides, Tetrasaccharides and Pentasaccharides depending upon number of Monosaccharides they yield on their hydrolysis.

Polysaccharides are non-sugar complex Carbohydrates which are formed because of interaction of large number of Monosaccharides. These Carbohydrates yield large number of Monosaccharides on hydrolysis.

Examples of Carbohydrates

Monosaccharides

Glucose is the most important and commonly known carbohydrate which belongs to Monosaccharides class. Other examples of carbohydrates of Monosaccharides class are Galactose, Allose, Altrose, Idose, Gulose and Talose. Monosaccharides are further divided into Aldoses and Ketoses which contain different Carbon atoms. Examples of each type of carbohydrate are given below.

Monosaccharides

(No. of Carbon Atoms)

Aldoses Ketoses
Trioses (3) Glyceraldehyde

CH2OHCHOHCHO

Dihydroxyacetone

CH2OHCOCH2OH

Trioses (4) Erythrose

CH2OH (CHOH)2CHO

Threose

Erythrulose

CH2OHCHOHCOCH2OH

Pentoses(5) Ribose

CH2OH(CHOH)3CHO

Arabinose, Xylose, Lyxose

Ribulose

CH2OH(CHOH)2COCH2OH

Hexoses (6) Glucose

CH2OH(CHOH)4CH2OH

Gulose, Talose, Idose, Allose, Altrose

Fructose

CH2OH(CHOH)3COCH2OH

Oligosaccharides

Maltose, Lactose and Sucrose are important examples of Oligosaccharides. They have same Chemical formula : C12H22O11 but different structure.

Polysaccharides

Starch, Glycogen and Cellulose are commonly known Polysaccharides.

Valuable Resources on Web

Videos

•    Carbohydrates

•    Carbohydrate Metabolism

•    Chemistry 3B – Lecture 25: Carbohydrates (Part 1)

•    Chemistry 3B – Lecture 25: Carbohydrates (Part 2)

Docs

•    Carbohydrates in the Diet

•    Importance of Carbohydrates

Importance of Carbohydrates

•    Chapter 7- Carbohydrates

Chapter 7- Carbohydrates

•    Carbohydrates