Question

In a DNA molecule, the phosphate group is attached to ____carbon of the sugar residue of its own nucleotide and _____ carbon of the sugar residue of the next nucleotide by ____bonds.

• A. 5', 3', phosphodiester
• B. 5', 3', glycosidic
• C. 3', 5', phosphodiester
• D. 3', 5', glycosidic

Answer 1

The correct option is A 5', 3', phosphodiester

A deoxyribonucleotide of DNA is formed by cross- linking of three chemicals - deoxyribose sugar $\left(C_5{H}_{10}{O}_4\right)$,a nitrogen base and phosphoric acid $\left(H_{3}P{O}_4\right)$. The backbone of a DNA strand is build up of alternate deoxyribose and phosphoric acid groups. The phosphate group is connected to carbon $5^{\prime }$ of the sugar residue of its own nucleotide and carbon $3^{\prime }$ of the sugar residue of the next nucleotide by phosphodiester bonds.

So, the correct answer is '5', 3', phosphodiester'.