Which factors affect enzyme activity?

• A. Color and odor
• B. Only substrate concentration
• C. Genetic code of enzyme
• D. pH and temperature

Answer: (D)

Enzyme activity is shaped by environmental conditions that affect the enzyme’s structure and the chemistry of the active site. The two classic factors are pH and temperature: temperature changes how often molecules collide and can push the enzyme toward denaturation if it’s too high, while pH alters the ionization of key residues and can disrupt bonds that hold the active site in the correct shape. Near the optimum range, activity is highest; outside it, activity drops off. Color and odor don’t influence enzyme function, substrate concentration does affect rate but only up to saturation and doesn’t capture how environment changes the enzyme’s shape, and the genetic code determines the enzyme’s properties but isn’t a variable factor you adjust to control activity in real time.