Question

On the basis of the two reactions below, decide which of the following statements are true and which are false. If a statement is false, explain why it is false.

1: ATP + Y--> Y-P + ADP ΔG = -100 kcal/mole
2: Y-P + A --> B ΔG = 50 kcal/mole

A. Reaction 1 is favorable because of the large negative ΔG associated with the hydrolysis of ATP.
B. Reaction 2 is an example of an unfavorable reaction.
C. Reactions 1 and 2 are coupled reactions, and when they take place together, reaction 2 will proceed in the forward direction.
D. Reaction 2 can be used to drive reaction 1 in the reverse direction.

Answer 1

Statement A is true because the hydrolysis of ATP releases a large amount of energy. Statement B is false because reaction 2 is exergonic. Statement C is true because reactions 1 and 2 are coupled. Statement D is false because reaction 2 cannot drive reaction 1 in the reverse direction.

Step-by-step explanation:

The first statement, A, is true. The hydrolysis of ATP to ADP releases a large amount of energy, about -7.4 kcal/mol. This makes reaction 1 favorable because it has a large negative ΔG.

The second statement, B, is false. Reaction 2 is actually an example of an exergonic reaction, which means it releases energy. This is because it has a positive ΔG of 50 kcal/mole.

The third statement, C, is true. Reactions 1 and 2 are coupled reactions, meaning the energy released from the hydrolysis of ATP in reaction 1 is used to drive reaction 2 in the forward direction.

The fourth statement, D, is false. Reaction 2 cannot drive reaction 1 in the reverse direction because reaction 2 releases energy and reaction 1 requires energy for ATP synthesis.