Enzymes

• Each enzyme lowers the activation energy of the reaction it catalyses.
• The induced module is as followed. The substrate collides with the active site causing it to change shape for the substrate. The active site & substrate form a enzyme-substrate complex. The active site then puts strain & force on the substrat which causes it to destabilise so lowers its activation energy. This force breaks the substrate forming a enzyme-product complex.
• Temperature affects enzyme activity via the following. As the temperature increases more collisions are occurring so more enzyme-substrate complexes form. The optimum temperature for enzymes is where most amount of collisions occur so has highest enzyme activity. As the temperature increases hydrogen bonds breaking so enzyme denatures and loses shape of active site.
• Each enzyme has an optimum pH. This refers to the amount of H+ ions present in a solution. Charged R-groups of amino acids making up active site are important for induced fit.
• How substrate concentration affects enzyme activity. The more substrate added, the more complexes can form the faster the reaction. At some point all the active sites are occuped. The enzymes becomes the limiting factor. The rate cannot get any faster and a plateau is seen.
• An enzyme inhibitors slows down the rate of an enzyme controlled reaction by affecting the enzyme molecule.
• A competitive inhibitor has a similar shape to substrate and binds to active site to prevent substrate from binding. Therefore less e-s complexes form so rate of reaction decreases. A competitive inhibitor can be outcompeted if the substrate concentration is increases
• Non-competitive inhibitor doesn't compete with substrate for active site but binds with another part of the active site. The inhibitor causes active site tertiary structure to distort and change shape so cannot form e-s complexes which reduces the rate of reaction.