Why does an enzyme-catalysed reaction stop speeding up at very high temperatures?
Answer and explanation
Correct answer: C. The enzyme is denatured
- Step 1: High temperature increases the vibration of atoms in the enzyme and breaks hydrogen and ionic bonds.
- Step 2: The tertiary structure and active site change shape, so substrate no longer binds.
Answer
The enzyme is denatured.
Why not the others: The substrate molecules are destroyed by the heat: the enzyme is the component that denatures first. The enzyme becomes more flexible and binds too many substrate molecules: denaturation reduces binding. The product molecules evaporate and cannot be measured: the cause is enzyme denaturation.
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