Explain how formation of an enzyme-substrate complex increases the rate of reaction.

When an enzyme comes into contact with a substrate that fits its active site, it will bind to it and form an enzyme-substrate complex. This binding alters some of the bonds in the substrate to be slightly weaker or easier to break. As chemical reactions require energy to take place, the reaction in question will require less activation energy to initiate. Therefore, the energy level to start the reaction will be reached faster for each enzyme-substrate complex in comparison to the substrate on its own. Hence, the rate of reaction is increased.