Question

Describe the features of double helical model of DNA.

Answer 1

The features of double helical DNA are

• It is made up of 2 polynucleotide of sugar phosphate and the nitrogen bases inside.
• The two chains have anti parallel polarity ie., one has 5′ —> 3’ polarity and the other with 3′ —> 5′ polarity. 
• The bases of 2 strands are joined by double hydrogen bond between adenine and thymine and triple hydrogen bond between guanine cytosine.
• The distance between 2 base pairs is 0.34 nm and the distance between each turn is 3.4 nm. Each turn consists of 10 base pairs.
• The plane of one base pair stacks over the other in double helen this gives the stability of double helical structure.