Coupling unfavorable reactions to ATP hydrolysis
A reaction has ΔG°′ = +14 kJ/mol. How can a cell drive it forward?
Answer A: explanation for every choice
A
Correct. ΔG values of coupled reactions add, so the total ΔG°′ of about −16.5 kJ/mol is favorable.
B
Enzymes change the rate, not ΔG.
C
High product concentration makes ΔG more positive. Removing products would help.
D
Lowering temperature does not make an endergonic reaction favorable in cells.
TakeawayCoupled ΔG values add. A large negative ΔG can drive an unfavorable step.
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Reviewed 2026-11-05 by a medical student. Spot an error? Report it with question ID bb72.