Question

All the following are naturally occurring nucleotides except

• A. Cyclic AMP
• B. ATP
• C. DNA
• D. Cyclic GMP

Answer 1

The correct option is D Cyclic GMP

Of the given options ATP, cAMP and cGMP are nucleotides and DNA is a polymer of nucleotides, i.e., DNA is polynucleotide. DNA is synthesized by joining together a number of nucleotides by phosphodiester bonds.

Adenosine triphosphate (ATP) is a nucleoside triphosphate used in cells as a coenzyme, often called as the "molecular unit of currency" of intracellular energy transfer.

Cyclic adenosine monophosphate (cAMP, cyclic AMP, or 3'-5'-cyclic adenosine monophosphate) is a second messenger important in many biological processes. cAMP is derived from adenosine triphosphate (ATP) and used for intracellular signal transduction in many different organisms, conveying the cAMP-dependent pathway.

Cyclic guanosine monophosphate (cGMP) is a cyclic nucleotide derived from guanosine triphosphate (GTP). cGMP acts as a second messenger much like cyclic AMP. Its most likely mechanism of action is activation of intracellular protein kinases in response to the binding of membrane-impermeable peptide hormones to the external cell surface.