Molecular Composition of DNA

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Molecular Composition of DNA

Genetic information is carried on a biological substance known as deoxyribonucleic acid (DNA), which is a double-stranded polymer of nucleotides. A DNA nucleotide is composed of deoxyribose sugar; a phosphate residue; and a purine or pyrimidine base.

Purines: adenine (A) and guanine (G)

Each purine contains 2 carbon-nitrogen rings

Pyrimidines: cytosine (C) and thymine (T)

Each pyrimidine contains 1 carbon-nitrogen ring