Question

A higher nucleotide is a nucleotide having

• A. Higher molecular weight.
• B. More than one phosphate radicle.
• C. More than one nitrogen base.
• D. More than one sugar residue.

Answer 1

The correct option is B More than one phosphate radicle.

Nucleotides are by definition phosphoric acid esters of nucleosides. Nucleosides are compounds of nitrogenous bases and pentose sugar- either ribose or deoxyribose. The nucleotides which form nucleic acids have only one phosphate group (monophosphates). Each of them can form a diphosphate and a triphosphate. Linkage of additional phosphate group occurs at the cost of a large amount of energy. The bonds that join the additional phosphate groups are called as high energy or energy rich bonds. Separation of these additional phosphate groups from the nucleotides by enzymatic hydrolysis releases correspondingly large amount of energy. Hence, these higher nucleotides (with one or two additional phosphates) form energy rich compounds, e.g., ADP, ATP, GTP etc.