STRUCTURE OF NUCLEOTIDE

Nucleotides are the basic units of nucleic acids (DNA and RNA). Nucleic acids are biomolecules essential for all forms of life.

A nucleotide has 3 components: image

1. Pentose sugar

2. Nitrogenous base

3. Phosphate sugar

Pentose Sugar

It is a monosaccharide with 5 carbon atoms. It forms the backbone of polynucleotide chain. It is also of 2 types.

1. Ribose sugar (which is present in RNA).

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2. Deoxyribose sugar (Which is present in DNA).

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In ribose sugar, at 2’ position OH group is present and in Deoxyribose sugar, at 2’ position only H is presence. Pentose sugar only decides whether the nucleic acid formed is Deoxyribonucleic acid or Ribonucleic acid.

Phosphate Group \left( PO_{4}^{3-} \right) :

Phosphate group is an organic salt of Phosphorus. It forms back bone of polynucleotide chain along with sugar.

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Nitrogenous Base:

Nitrogenous base is a compound that contains nitrogen and has the chemical properties of base.

There are two types of nitrogenous base:

1. Purines

2. Pyrimidines

Purines: Purines are heterocyclic aromatic organic compound. It is a 9 membered double ring containing 4 nitrogen and 5 carbon atoms.

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Examples: Adenine and Guanine

Pyrimidines: Pyrimidines are also heterocyclic aromatic compound but unlike purine it is a 6 membered chain containing 2 nitrogen and 4 carbon atoms.

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Examples: Cytosine, Uracil and Thymine

FLOW CHART OF STRUCTURE OF A NUCLEOTIDE

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Post Author: E-Biology

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