Adenylate energy charge ratio

Karl. D.M. and Holm-Hansen, O., 1978. Methodology and measurement of adenylate energy charge ratios in environmental samples. Msir. Biol., 48 185—197. 

Fig. 12. Response of phosphorylation of acetyl-CoA carboxylase to the adenylate energy charge. Acetyl-CoA carboxylase-protein kinase preparation was preincubated as described in Fig. 1 at 37°C for 30 minutes, and then different ratios of AMP to ATP of [y.32p]ATP were added for further incubation for 1 minute. P-labeled enzyme was then...

Changes in a variable diffusion barrier may affect the EAC in at least two ways. First, variations in the ATP concentration or ATP/ADP ratio with O2 concentration may have a direct effect on the EAC, as discussed above. For example. Miller et al (1985) showed that low root temperature in alfalfa (Me-dicago sativa) resulted in increases in both adenylate energy charge and EAC. It would be interesting to determine whether effects on the EAC caused by changes in carbohydrate supply to nodules, or the reported differences in EAC... 

Thus ATP is the effective controller of metabolism but because AMP + ADP + ATP is constant, it is really the ratio of adenine nucleotides which is important This ratio is termed die adenylate charge or energy charge and is expressed as ... 

The energy charge quotient has a value of unity (or, 1.00) when only ATP is present and a value of zero when only AMP is present. Thus, the adenine nucleotide system is said to be fully charged at EC = 1 and fully discharged at EC = 0. At intermediate values, the adenine nucleotides are interconverted by adenylate kinase, and their concentrations are constrained by the adenylate kinase mass action ratio ... 

In living organisms, the adenosine phosphates are in equilibrium and are regarded collectively as the adenylic acid system. The physiological concentrations of ADP and ATP are around 10 mol/1. The ratio of the forms is called the energy charge (EC), and... 

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