alleryStart learning →Why does having two different enzymes for the two directions of a reversible reaction improve control?
AIt means equilibrium is not reached
BIt means no enzyme is ever needed
CIt means the reaction runs only once
DIt means the products cannot leave
Answer & Solution
Correct answer: A. It means equilibrium is not reached
1. Reactions catalysed by only one enzyme can go to equilibrium, which stalls them.
2. If two different enzymes are needed, each specific for one direction, the opportunity to control the rate increases.
3. Equilibrium is then not reached, so the reaction keeps running usefully.
4. Each direction can be switched on or off independently of the other.
5. An answer claiming no enzyme is needed misses that both directions still require catalysis.
6. Nothing about a two-enzyme arrangement traps products inside the cell.
_Source: OpenStax Biology (1st ed., CC BY 4.0), Ch 7 "Cellular Respiration", section 7.7 Regulation of Cellular Respiration_
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