Problem: Firefly luciferase is the enzyme that allows fireflies to illuminate their abdomens. Because this light generation is an ATP-requiring reaction, firefly luciferase can be used to test for the presence of ATP. In this way, luciferase can test for the presence of life. The coupled reactions areIf the overall ΔG° of the coupled reaction is –7.70 kJ/mol,  what is the equilibrium constant, K, of the first reactions at 15°C? The ΔG° for the hydrolysis of ATP to AMP is −31.6 kJ/mol.

FREE Expert Solution

We’re being asked to determine the equilibrium constant (K) at 15 ˚C for the first reaction.


Recall that ΔG˚rxn and K are related to each other:


ΔG°rxn=-RTlnK


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Firefly luciferase is the enzyme that allows fireflies to illuminate their abdomens. Because this light generation is an ATP-requiring reaction, firefly luciferase can be used to test for the presence of ATP. In this way, luciferase can test for the presence of life. The coupled reactions are

If the overall ΔG° of the coupled reaction is –7.70 kJ/mol,  what is the equilibrium constant, K, of the first reactions at 15°C? The ΔG° for the hydrolysis of ATP to AMP is −31.6 kJ/mol.

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