How Temperature, pH, and Substrate Concentration Affect Enzyme Activity
- Temperature, pH, and substrate concentration, influence the rate of enzyme-catalyzed reactions.
- Understanding these effects requires exploring collision theory and denaturation.
Temperature and Enzyme Activity
- As temperature rises, molecules gain kinetic energy, moving and colliding faster.
- This increases the frequency of enzyme-substrate collisions, raising the reaction rate.
The rate of enzyme activity typically doubles for every 10°C increase in temperature, up to a certain point.
Beyond the Optimum: Denaturation
- Each enzyme has an optimum temperature where its activity is highest.
- Beyond this temperature, high temperatures cause the enzyme to denature, disrupting its structure and active site.
- This denaturation reduces or halts enzyme activity, as the enzyme can no longer bind to the substrate effectively.
- Denaturation occurs when the bonds maintaining the enzyme’s three-dimensional shape are disrupted, altering the active site.
pH And Enzyme Activity
- Enzymes have an optimum pH where the active site is in the best shape for substrate binding.
- pH affects the ionic and hydrogen bonds that maintain the enzyme's structure.
- At the optimum pH, these bonds stabilize the active site in its most functional configuration.
pH deviation: Denaturation
- If pH is too acidic or too basic, these bonds are disrupted.
