What are Enzymes and how do they function? Enzymes are extremely efficient and very important catalysts for biochemical reactions. They speed up the rate of a reaction by offering an alternative reaction pathway of lower activation energy. However remain unchanged at the end of the reaction. Enzymes are usually highly specific, only catalysing certain reactions. Enzymes have a specific active site shape, which fits only a specific substrate to form the enzyme substrate complex. Enzymes are proteins built from a series of amino acids usually folded into a globular structure. Many enzymes also contain a non-protein part, called a cofactor. Cofactors can be one of a few things; organic molecules that may be vitamins or made from vitamins these are not bound to the enzyme permanently, but bind with the enzyme substrate complex temporarily. This type of cofactor is called a coenzyme. Organic groups permanently bound to the enzyme, which are known as prosthetic groups. Or positively charged metal ions known as activators, these temporarily bind to the active site of the enzyme, this causes the protein to become strongly positively charged. Enzymes can be denatured by extremes of temperature and pH due to the intra- and intermolecular bonds being disrupted by the changes, these changes in bonding cause the active site to change shape so it …show more content…
The energy to break the existing bonds in the molecule needs to be overcome before the reaction can take place, this is called the activation energy. A catalysed reaction takes a different reaction pathway with a lower activation energy (figure 1), this in turn speeds up the rate of the reaction. The active site is where the substrate binds to the enzyme as it is a complimentary shape to the substrate, it has the correct molecules in the right places in order to bind and form the enzyme substrate