Question

Write an short essay about How can enzymes speed up the metabolic reactions

Answer 1

Enzymes are soluble catalyst that enhances the speed of reaction by reducing the activation energy required for the reaction.

some enzymes are specific to one reaction only ,while most of the enzymes can act on multiple reactions with similar properties.This is because enzymes will match the shape of only specific substrate active sites.Although enzymes speeds up chemical reaction by reducing activation energy but they are not used up with in the chemical reaction.

Activation energy is the amount of energy required to start a chemical reaction.If less energy is required to start the reaction, then the reaction will start faster.Enzymes able to lowers Activation energy by -

1)Providing an alternate pathway for the reaction

2)Stabilizing the transition state ( substrate+enzyme complex)of a reaction

3)Destabilizing the substrate ground state of the reaction.

Many enzymes consists of a protein and a non-protein(co-factor).The proteins in enzymes are usually globular.The bonds that hold proteins in enzymes can be shaken by altering the temperature and PH.co-factors may be

-prosthetic groups that are permanently bound to the enzymes

-activators that are positively charged metal ions,which temporarly bind to the active site of the enzyme,giving an intense positive charge to enzymes protein.

-co-enzymes that are organic molecules usually vitamins,which are not permanently bound to enzyme molecules.

Enzymes have an active site(it is part of a molecule that has just the right shape and functional groups to bind to one of the reaacting molecules).The reacting molecule that binding to to enzyme is known as substrate.Enzyme-catalysed reaction takes a different route.The enzyme and substrate form a reaction intermediate .its formation lowers the activation energy than the reaction without a catalyst.

The enzyme molecule changes the shape as the substrate molecules gets closer.The change in shape is induced by approaching substrate molecule,because molecules are flexible due to single covalent bond and are free to rotate because of single bond.All this phenomenon is known as INDUCED FIT HYPOTHESIS.