Factors affecting enzyme action

• Rate of reaction is quickest at the start because there are more collisions between enzymes and substrates
• Rate of reaction decreases as time goes on - substrate used up so fewer collisions
• As temperature increases, the rate of reaction increases until the optimum temperature when they begin to denature and slow the reaction down
• pH is the measure of the hydrogen ion concentration of a solution
• If pH too high or low, enzymes become denatured (change shape) which affects rate of reaction
• Extreme pH affects/breaks hydrogen and ionic bonds in the tertiary structure, which changes the shape of the active site
• As enzyme concentration increases, more collisions between active site and substrate leads to a faster rate and more complexes forming
• At a certain point, every substrate has bound to an active site so further increasing concentration has no effect on rate
• As substrate concentration increases, more collisions between substrate and active site leads to more reactions
• All active sites are occupied at high substrate concentration so further increasing concentration has no effect on rate