Which of the following statement is correct about the mechanism of an enzyme-catallysed reaction?

Options

A. An enzyme begins its action by forming a monovalent enzyme-substrate complex
B. An enzyme promotes the appropriate chemical reaction in the enzyme-subtract complex to give an enzyme-product complex?
C. The formation of an enzyme-substrate complex, its conversion to enzyme-product complex and the decomposition of the latter to product and enzyme are all reversible reactions
D. All are correct

Answer

D

Explanation

In case of enzymatic reaction, the enzyme is so built that it binds to the substrate in a specific manner. The enzymatic reaction may proceed through the following four stages:
(i) the formation of complex between enzyme and substrate `(ES)`,
(ii) the conversion of this complex to an enzymes intermediate complex `(EI)` and
(iii) further conversion to a complex between enzyme and product `(EP)` and
(iv) the dissociation of the enzyme - product complex leaving the enzyme enchanged.
Enzyme + substrate `hArr` enzyme - substrate complex `hArr` enzyme - product
Enzymes are needed only is small quantities for the progress or a reaction. Similar to the action of chemical catalysts, enzymes are said to reduce the magnitude of activation energy. For example, activation energy for acid hydrolysis of sucrose is `6.22 kJ mol^(-1)`, white the activation energy is only `2.15 kJ mol^(-1)` when hydrolysed by the enzyme, sucrase.