Question

The ‘‘lock and key’’ model of enzyme action illustrates that a particular enzyme molecule

• A. May be destroyed and resynthesised several times
• B. Interacts with a specific type of substrate molecule
• C. Reacts at identical rates under all conditions
• D. Forms a permanent enzyme-substrate complex

Answer 1

The correct option is B Interacts with a specific type of substrate molecule

The ‘‘lock and key’’ model of enzyme action illustrates that a particular enzyme molecule interacts with a
specific type of substrate molecule. The lock is the enzyme and the key is the substrate. Only the correctly
sized key (substrate) fits into the key hole (active site) of the lock (enzyme).