Catalysts vs Enzymes

CATALYSTS VS ENZYMES

What is chemical reaction?
It is when substance reacts and changes in some way.
Enzymes are protein molecules, and so are made up of amino acids. Most enzymes contain between 100 and 1,000 amino acids
These amino acids are joined together in a long chain,  which is folded to produce a unique 3D structure.
Why is shape important?
The shape of an enzyme is very important because it has a direct effect on how it catalyzes a reaction.
Why do enzymes have different shapes?
They contain different amino acids which fold to give a different 3D shape


Why are enzymes so specific?
Only molecules with exactly the right shape will bind to the enzyme and react. These are the reactant, or substrate, molecules.
The part of the enzyme to which the substrate binds is called the active site.
Lock and key theory
•Enzymes have a specific 3D structure
•They exactly match the shape of a molecule of substrate
Substrate   ------------>   Products
•The substrate binds with the enzyme to form an enzyme-substrate complex.
  The product(s) are then released

WHAT AFFECTS ENZYME CONTROLLED REACTIONS?
Substrate concentration – increasing substrate concentration increases the rate of reaction until all active sites are full.
Enzyme Concentration – as the concentration of enzyme is increased the rate of reaction increases as more enzyme-substrate complexes can be formed.
Every enzyme has an optimum (best) temperature and pH.

Enzymes and temperature

        If the temperature around the enzyme is above the optimum then the enzyme loses its specific shape so that it is no longer complementary to its substrate.  This means that the substrate can no longer bind and the rate of reaction will reduce/stop.

ENZYMES AND pH

        Amino acids within proteins have charges that can be changed when the surrounding pH changes.  This causes the shape of the enzymes and its active site to change so that the substrate can no longer bind.

https://www.youtube.com/watch?v=qgVFkRn8f10 click on this for summary.

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