Question

The efficiency of an enzyme in catalysing a reaction is due to its capacity
(a) to form a strong enzyme-substrate complex
(b) to decrease the bond energies of substrate molecule
(c) to change the shape of the substrate molecule
(d) to lower the activation energy of the reaction

Answer 1

Acc. to me,

answer is d --lower activation energy

When many molecules of reactant collides in itself then then minimum energy required to make product is known as activation energy. Simply it activate the reactant to make product.

For example--There are 30 reactant molecules and  a reactant wants 15j energy to make product and 4 reactant are capable to form product at that energy. but when enzyme comes and participate in reaction then it lower the activation energy means for catalyst coming the decrease the min. energy to approx 10j then more reactants participate in reaction at first only 4 reactant form product but when catalyst comes  it decrease in requirement to 10j then approx 7 reactant can afford them and make product.means lower activation energy lower requirement and more reactn fast.

I hope it help