Question

Some enzyme catalysed reactions which occur at metal surfaces are:

• A. first order reactions
• B. second order reactions
• C. third order reactions
• D. fractional order reactions
• E. zero order reactions

Hint:

For enzyme-catalyzed reactions at metal surfaces, once all the enzyme sites are saturated with the reactant, the reaction rate becomes constant and follows zero-order kinetics.

Answer 1

Answer: (E)

Enzyme-catalyzed reactions that occur at metal surfaces often follow zero-order kinetics. This happens because, in such reactions, the reaction rate is independent of the concentration of the reactants after a certain concentration has been reached. At this point, all the enzyme active sites are occupied, and the reaction rate becomes constant, which is characteristic of zero-order reactions.
For zero-order reactions, the rate law is given by: \[ {Rate} = k \] where \( k \) is the rate constant and is independent of the reactant concentration. This is in contrast to first-order or second-order reactions where the rate depends on the concentration of the reactants.
Therefore, the correct answer is zero-order reactions, which are common for some enzyme catalyzed processes at metal surfaces.