AAT Bioquest

What are the factors affecting enzyme activity?

Posted May 19, 2023


Every enzyme works most efficiently under optimum conditions of temperature, pH, enzyme concentration, substrate concentration, and presence of activators. Sub-optimal conditions can affect an enzyme’s ability to bind to a substrate, impacting its overall activity and efficiency. Here’s how different factors affect enzyme activity. 

  • Temperature - Enzyme activity is most efficient within a narrow range of temperatures. Every enzyme has an optimal temperature range at which it is most efficient. Enzyme activity gradually decreases as the temperature increases or decreases beyond the optimal temperature. Enzyme activity ceases at its maximum temperature limit. Beyond its maximum limit, an enzyme gets denatured and stops working. Enzyme activity is the least at its minimum temperature limit and stops completely when the temperature reaches 00 C. It gets reactivated if the temperature increases. 
  • pH - Every enzyme has an optimum pH range at which it is most efficient. Enzyme activity slows down if the pH is outside of this range. At extreme pH values, enzymes get denatured and stop working. Most enzymes work at neutral pH 7.4.
  • Enzyme concentration - When enzyme concentration increases, there is a corresponding increase in enzyme activity but this is only as long as there is substrate available to bind to. Once all of the substrate is bound, there is nothing for the additional enzymes to bind to. At this point the reaction cannot speed up any further. 
  • Substrate concentration - Enzyme activity increases with an increase in substrate concentration but only up to a certain limit. At a certain substrate concentration, enzyme activity will have reached its peak as all of the available enzymes will be saturated. Further increase in substrate concentration will not affect the reaction rate. 
  • Activators - Some enzymes exhibit peak activity in the presence of certain metallic cations such as Na+, Zn2+, K+, Cu2+, Mn2+,Ca2+, Co2+, and Mg2+.  Anions are very rarely required for enzyme activity. For example, amylase requires a chloride ion CI.
Additional resources

Regulation of enzyme activity in the cell: effect of enzyme concentration


Amplite® Universal Fluorimetric Protease Activity Assay Kit *Green Fluorescence*