4. An energy charge (EC) of 0.9 is roughly 80% ATP, 17% ADP, and 3% AMP. At this EC, enzyme activities are low, and enzyme activities higher. a. ATP generating; ATP utilizing b. ATP generating; NADH producing c. ATP utilizing; ATP generating d. ATP utilizing; NADH producing e. NADH producing; ATP generating

a. ATP generating; ATP utilizing

Explanation:

The energy charge is defined as the chart or index which is used to measure the energy of any biological cell.

This concept was proposed by the Atkinson and Walton in 1968 based on the principle that energy is stored in the adenine nucleotide in an organism that is ATP, ADP and AMP.

2 ADP= ATP+ AMP or ATP+ 1/2 ADP/ ATP+ADP+AMP

The energy charge value lies between the 0.6 to 1.0 and if the value rises towards the 1, suggests that the ATP demanding reaction is occurring more than the ATP synthesizing reactions.

Therefore in the given question, when the EC is 0.9, the ATP generating enzymes are low compared to the ATP demanding enzymes.

Thus, Option-A is correct.

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