Concept:Enzyme kinetics follows a saturation curve. The reaction rate is limited by the physical number of active sites available.
Solution:- Initially, adding substrate speeds up the reaction because there are plenty of empty enzymes.
- However, once all active sites are occupied (saturated), the enzyme is working at its maximum velocity (\( V_{max} \)).
- When very few enzyme molecules are left unsaturated, the system is essentially at full capacity. Adding more substrate at this point will not yield any significant increase in the reaction rate because there are no available active sites to process it.
Why other options are incorrect:If 'many' enzymes are unsaturated (Option D), adding substrate
will make a huge difference. Heating or cooling the substrate changes kinetic energy, but doesn't directly address the specific chemical concept of enzyme saturation limits.
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