Question

Which of the following best describes the relationship between the shape of enzymes and the reactions they catalyze? The shape of an enzyme depends on the reaction that it needs to catalyze. Enzymes with more active sites can catalyze several reactions at once. The shape of an enzyme determines which reaction it can catalyze. Enzymes change shape after they catalyze a reaction and become waste products.

Answer 1

Answer: The shape of an enzyme determines which reaction it can catalyze.

Explanation: Enzymes are defined as bio chemical catalysts which enhance the rate of reactions in living systems.  

Each enzyme catalyses only one chemical reaction. Thus enzymes are highly specific in their action. The specificity of enzymes is due to the presence of some specific regions called as active sites on their surface.

The shape of the active site of any given enzyme is like a cavity such that only a specific substrate can fit into it, in the same way as the key can fit into a particular lock. This specific binding accounts for high specificity of enzyme catalyzed reactions.

Enzymes are regenerated at the end of the reaction.

Answer 2

"The shape of an enzyme determines which reaction it can catalyze" would be the best option from the list, since most enzymes can only do their job if they "fit" into the structure that they wish to enhance, or "speed up".