Question

Explain chemical constituents of DNA

Answer 1

DNA is deoxyribonucleic acid. It contains the genetic information. A double-stranded DNA consists of 2 helices which are anti-parallel. It is made up of monomer called nucleotides. It is made up of 3 components, namely a sugar group, a phosphate group, and a nitrogen base. Nucleotide without phosphate group is called as a nucleoside. In DNA, the sugar present is deoxyribose sugar. The sugar and phosphate group makes the backbone of the DNA molecule. There are two types of nitrogen bases present. These are purine and pyrimidines. Purines include There are four different bases that can potentially be attached to the sugar group: adenine (A) and guanine (G) and pyrimidines include thymine (T) and cytosine (C). The hydrogen bond between these bases holds the two strands together. There are 2 hydrogen bonds present between adenine and thymine and 3 hydrogen bonds are present between guanine and cytosine. Hence, adenine and thymine are called complimentary pairs. Similarly, guanine and cytosine are called complimentary pairs.