Explain the structure of DNA.

1.	Explain the structure of DNA.
Answer» The salient features of the double-helix. Structure of DNA are as following: (i) It is made of two polynucleotide chains, where the backbone is constituted by sugar-phosphate and the bases project inside. (ii) The two chains have anti-parallel polarity. It means, if one chain has the polarity 5'-3', the other has 3'-5'. (iii) The bases in two strands are paired through hydrogen bond (H-bonds) forming base pairs. Adenine forms two hydrogen bonds with thymine from opposite strand and vice-versa. Similarly, Guanine is bonded with cytosine with three H-bonds. (iv) The two chains are coiled in a right handed fashion. (v) The plane of one base pair stacks over the other in double helix.

Answer»

The salient features of the double-helix.

Structure of DNA are as following:

(i) It is made of two polynucleotide chains, where the backbone is constituted by sugar-phosphate and the bases project inside.

(ii) The two chains have anti-parallel polarity. It means, if one chain has the polarity 5'-3', the other has 3'-5'.

(iii) The bases in two strands are paired through hydrogen bond (H-bonds) forming base pairs. Adenine forms two hydrogen bonds with thymine from opposite strand and vice-versa. Similarly, Guanine is bonded with cytosine with three H-bonds.

(iv) The two chains are coiled in a right handed fashion.

(v) The plane of one base pair stacks over the other in double helix.

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