Question

Select all that are correct regarding enzyme mechanisms: when substrate binds, enzyme conformation does not change? enzymes bind a specific substrate to form an enzyme-substrate complex? enzyme active sites stress chemical bonds of the substrate? once the reaction is over, enzymes are degraded and recycled?

1) when substrate binds, enzyme conformation does not change
2) enzymes bind a specific substrate to form an enzyme-substrate complex
3) enzyme active sites stress chemical bonds of the substrate
4) once the reaction is over, enzymes are degraded and recycled

Answer 1

Correct statements about enzyme mechanisms are that enzymes bind specifically to substrates forming enzyme-substrate complexes, and enzyme active sites stress substrate bonds. Enzymes are not degraded post-reaction but are recycled.

Step-by-step explanation:

The statements regarding enzyme mechanisms include that enzymes bind a specific substrate to form an enzyme-substrate complex and that enzyme active sites stress chemical bonds of the substrate. During this process, enzymes undergo a conformational change to accommodate the substrate, known as induced fit, contrary to the idea that they remain unchanged. Once the reaction is completed, enzymes are not degraded but are recycled to catalyze new reactions.

An enzyme molecule possesses an active site that binds to a specific substrate, forming an enzyme-substrate complex. The active site of an enzyme is shaped in such a way that only one particular substrate can bind to it, giving enzymes their specificity. Enzymes stress the chemical bonds of the substrate at their active site, promoting the reaction and lowering the activation energy. Once the reaction is complete, the enzyme is left unchanged and ready to catalyze another substrate.