Question

Choose the correct option.

• A. $E + S \longrightarrow ES \longrightarrow E + P \longrightarrow EP$
• B. $E + S \rightleftharpoons ES \rightarrow E - P \longrightarrow E + P$
• C. $E + S \longrightarrow ES \rightleftharpoons E - P \longrightarrow E + P$
• D. $E + S \rightleftharpoons ES \rightleftharpoons E - P \rightleftharpoons E + P$

Answer 1

Answer: (B)

Each enzyme $(E)$ has a substrate $(S)$ binding site in its molecule, so that a highly reactive enzyme substrate complex $(ES)$ is produced. This complex is short-lived and dissociates into its product and the unchanged enzyme with an intermediate formation of the enzyme product complex $(EP)$.
Thus, the correct representation is
$E + S \rightleftharpoons ES \longrightarrow E - P \longrightarrow E + P$