Factors that affect enzyme

Generally, increasing temperature increases the rate of reaction because more molecules have sufficient kinetic energy to overcome the activation energy. However, beyond the optimum temperature, the enzyme denatures, and the rate decreases rapidly.

Enzymes have an optimum pH at which they function most effectively. Deviations from this pH can disrupt the ionic and hydrogen bonds that maintain the enzyme's tertiary structure, leading to denaturation and reduced activity.

A competitive inhibitor binds to the active site of an enzyme, preventing the substrate from binding. This reduces the rate of reaction. Increasing the substrate concentration can overcome competitive inhibition.

Non-competitive inhibitors bind to an allosteric site on the enzyme, changing its shape and reducing its activity. Vmax is decreased because fewer functional enzyme molecules are available, and Km remains unchanged because the inhibitor does not affect substrate binding to the active sites that are still functional.

Immobilised enzymes are more stable and can be reused, reducing costs. Also, the product is not contaminated with the enzyme, simplifying downstream processing.

When substrate is in excess, increasing the enzyme concentration increases the rate of reaction. This is because there are more active sites available to bind with substrate molecules, leading to more product formation per unit time.

Initially, increasing substrate concentration increases the rate of reaction as more active sites are occupied. However, as substrate concentration continues to increase, the rate plateaus, eventually reaching Vmax, because all active sites are saturated.