Structural elements of common nucleic acid constituents. The compounds marked nucleoside monophosphate,nucleoside diphosphate and nucleoside triphosphate are all nucleotides.
Nucleotides are organic molecules that serve as the monomers, or subunits, of nucleic acids like DNA and RNA. The building blocks of nucleic acids, nucleotides are composed of anitrogenous base, a five-carbon sugar (ribose ordeoxyribose), and at least one phosphate group.
Nucleotides serve to carry packets of energy within the cell (ATP). In the form of the nucleoside triphosphates (ATP, GTP, CTP and UTP), nucleotides play central roles in metabolism. In addition, nucleotides participate in cell
signaling (cGMP and cAMP), and are incorporated into important cofactors of enzymatic reactions (e.g. coenzyme A,FAD, FMN, NAD, and NADP+).
Ans : (A)