Enzymes are proteins that act as biological catalysts. They increase the rate of chemical reaction by lowering the activation energy required for reactions to occur. This allows more reactant molecules to have sufficient energy to reach the transition state so that the reaction can proceed more easily. 

Activation energy is the energy needed for two or more reactants to come together and trigger a chemical reaction. Some reactions need a great amount of activation energy, which often acts as an obstacle, hindering the reaction between reactants. Enzymes reduce the activation energy that the reactants need to come together and react, increasing the rate of chemical reaction. 

There are multiple ways in which enzymes lower the activation energy and increase the rate of chemical reaction: 

• Enzymes bind to their substrates at a specific region called the active site, forming an enzyme-substrate complex. This interaction reduces the energy required to overcome intermolecular forces that would otherwise inhibit the reaction. 
• They may bring reactant molecules into close proximity, making it easier for them to interact. This reduces the need for reactants to expend energy moving about until they randomly collide with enough energy to react.
• Enzymes may guide the reaction along an alternate pathway that has a lower activation energy compared to the non-catalyzed reaction.
• Enzymes may decrease the activation energy required for the reaction by weakening the bonds and facilitating the formation of the transition state. This reduction in activation energy means that more reactant molecules have sufficient energy to react, thereby increasing the reaction rate.

The rate at which enzymes increase the rate of chemical reaction may be influenced by factors such as temperature, ionic conditions, and the pH of the environment, which can affect the enzyme’s structure and its ability to bind substrates and catalyze reactions.