The isomerization of 3-phosphoglycerate (3PG) to 2-phosphoglycerate (2PG) has a ΔG°´ = +4.4 kJ/mol. If [2PG] = 4.0 mM and [3PG] = 22.2 mM, in which direction will the reaction move to reach equilibrium at 37°C?

The reaction will move to the right, that is, the formation of 2PG

Explanation:

Data:

Reaction:

3PG ↔ 2 PG

This variables are related by the following equation:

ΔG° = -R*T*ln(Kp)

Replacing with data:

4400/(-8.3144*310) = ln(Kp)

Kp = e^(-1,71)

Kp = 0,1813

For the given reaction the equilibrium constant is:

Kp = [2PG]/[3PG]

Replacing with data:

Kp' = 4/22.2 = 0.18018

which is barely less than the equilibrium constant at the temperature of interest. Then, the concentration of 3PG must be reduced and the concentration of 2PG must be increased.

your answer would be a. 12.5 kg