What are the 3 factors that can change the rate of enzyme reaction?

The first factor is Enzyme concentration or subtrate concentration.The rate of enzyme action is directly proportional to to the availability of enzyme provided the substrate concentration unlimited.Or the rate is directly proportional to the substrate concentration if enzymes are limited but if enzyme concentration is kept constant then upto the certain level the increase in substrate amount will no longer increase the rate of enzyme action.

Second factor is temperature.The rate if an enzyme action is always directly proportional to the increase in temperature but upto the specific limit called as optimum temperature.

Third factor is the pH value.Enzymes can work efficiently over a narrow range of pH called as Optimum pH.A minor change in pH value can denature the enzyme.