Human Biochemistry, Volume 1 - Murray R. 1993

Bioenergetics and Metabolism of Carbohydrates and Lipids
Bioenergetics
Pyrophosphate Metabolism

Reactions involving ATP that yield AMP are accompanied by The formation of inorganic pyrophosphate (PP_i); an example is the activation of long-chain Fatty acids:

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This reaction is accompanied by the dissipation of Free energy as heat, which drives it forward. This direction is further favored by the hydrolytic Cleavage of PP_i catalyzed by inorganic pyrophosphatase, which has a large negative ∆G°' value (-4.6 kcal/mol). Note that activation involving pyrophosphate formation results in the loss of two rather than one, as is the case when ADP and P_i are formed:

Fig. 11.11. Coupling of phosphate cycles with the interconversion of adenine NUCLEOTIDES.

The reactions involving phosphate and adenine nucleotides described above are schematically illustrated in Fig. 11.11.

Nucleoside Phosphates Related to ATP and ADP

With the participation of the enzyme nucleoside diphosphate kinase, nucleoside triphosphates analogous to ATP, but containing a base other than adenine, can be synthesized from their respective diphosphates:

All of these triphosphates take part in cellular phosphorylation reactions. Nucleoside monophosphate Kinases, specific for particular purine or pyrimidine nucleoside phosphates, catalyze the formation of nucleoside diphosphates from the corresponding monophosphates.

Specifically, adenylate kinase is a monophosphate kinase with narrow Specificity.

References

Ernster L. (ed.) Bioenergetics, Elsevier, 1984.

Harold F. M. The Vital Force: A Study of Bioenergetics, Freeman, 1986.

Klotz l. M. Introduction to Biomolecular Energetics, Academic Press. 1986.

Krebs H. A., Kornberg H. L. Energy Transformations in Living Matter, Springer, 1957.

Lehninger A. L. Bioenergetics: The Molecular Basis of Biological Energy Transformations, 2nd ed., Benjamin, 1971.