Hydrolysis of nucleoside triphosphates provides chemical energy.
ATP is the most widely used for energy.
When coupled to a reaction with a positive free energy change, ATP hydrolysis shifts the equilibrium to favor product formation.
Hydrolysis of the ester linkage yields about 14 kJ/mol.
Hydrolysis of each anhydride bond yields about 30 kJ/mol
CTP hydrolysis can be a source of chemical energy
Adenosine does not participate directly in the primary function, but its removal reduced cofactor activities.
Nucleotide binding fold is a single protein domain that bonds adenosine.
CoenzymeA
Nicotinamideadeninedinucleotide, NAD+
Flavin adenine dinucleotide, FAD
Secondary messengers are compounds that are produced inside the cell following the interaction of extracellular chemical signals with receptors.
Secondary messengers are often nucleotides, such as adenosine 3', 5'-cyclic monophosphate, or cAMP.
ppGpp is produced in bacteria during amino acid starvation to inhibit the synthesis of the rRNA and tRNA molecules.
Cyclic AMP, or cAMP
Cyclic GMP, or cGMP
Guanosine 5'-diphosphate, 3'-diphosphate, guanosine tetraphosphate, or ppGpp
ATP and ADP serve as neurotransmitters in a variety of signaling pathways, signals for receptors that mediate pain sensation, or blood clotting signals.