How do enzymes lower the activation energy of reactions?

Enzymes are biological catalysts for lowering activation energy - the speed up the rate of reactions and all allow biological reactions involved in metabolic processes to take place at body temperature (37C). You may have previously been most familiar with the lock and key model of enzyme action. In this model, the shape of the substrate (e.g. lactose) fits the site of an enzyme (e.g. lactase) exactly and the active site is considered to be an rigid structure. However, enzyme action is now considered to be more flexible so the induced fit model is a modified version of enzyme action. The induced fit model: Importantly - the enzyme is flexible and the proximity of the substrate causes a change in the shape of the active site prior to binding, this then allows binding, rather than a perfect fit like in the lock and key model. The active site is made up of a relatively small number of amino acids, when a substrate-enzyme complex is formed, temporary bonds form between these amino acids and groups of the substrate model. When the substrate binds, the enzyme moulds itself around the substrate, putting strain on the substrate molecule. The strain distorts bonds within the substrate molecule, lowering the activation energy required to break the bond. --> Diagram of what lowering activation energy does