What is the structure formed by adenosine and two phosphate groups called?

The structure formed by adenosine and two phosphate groups is known as adenosine diphosphate (ADP). In biochemistry, ADP is a nucleoside diphosphate, consisting of an adenosine molecule (which itself is made up of adenine and ribose) bonded to two phosphate groups.

ADP takes part in cellular energy transfer processes, particularly in cellular respiration and photosynthesis, where it serves as a building block for the generation of adenosine triphosphate (ATP) when a third phosphate group is added during phosphorylation. This conversion is crucial in cellular energy metabolism since ATP serves as the primary energy currency in biological systems.

The other options refer to different structures or functions: adenosine triphosphate (ATP) includes three phosphate groups, a nucleotide has a nitrogenous base, a sugar, and at least one phosphate group, and a coenzyme generally refers to a smaller organic molecule that assists enzymes in catalyzing reactions but does not directly describe the molecule in question.