Activation energy for the acid catalysed hydration of sucrose is $6.22 \ kJ \ mol^{-1}$,while the activation energy is only $2.15 \ kJ \ mol^{-1}$ when hydrolysis is catalysed by the enzyme sucrase. Explain.

(N/A) Enzymes act as biological catalysts that increase the rate of reaction by providing an alternative pathway with a lower activation energy.
In the case of sucrose hydrolysis,the acid-catalyzed reaction requires an activation energy of $6.22 \ kJ \ mol^{-1}$.
When the enzyme sucrase is used,it lowers the activation energy to $2.15 \ kJ \ mol^{-1}$.
This reduction in activation energy allows a larger fraction of reactant molecules to possess sufficient energy to cross the energy barrier at a given temperature,thereby significantly increasing the reaction rate.