SHORT NOTE ON ENZYME

                          ENZYMES

Enzymes are-
1)colloidal,thermolabile;protein in nature.
2)Synthesized by living cells.
3)They may catalyze thermodynamically either inside or outside the cell.

Substrate:
Substances on which enzymes act to convert them into product are called substrate.
 E+ [S] --------->  [ES]------>E + P
           <---------

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1)Coenzyme:   Non protein, Organic substance; EX:NAD+
2)PROSTHETIC GROUP: Non protein, Non dialysable Ex:FAD+
3)CO FACTOR: Non protein, either organic or inorganic.
It is two types:-----
1)Metal-activated enzymes
Ex:Na+, ca++
2)Metalloenzyme
Ex:Mn, Mo
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**Classification of coenzyme
1) First group of coenzyme
2) Second group of coenzyme
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The protein part of the enzyme is called apoenzyme.It is heatlabile.
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HOLO ENZYME:  The complete structure of apoenzyme and prosthetic group is called Holoenzyme.
Ex:RNA Polymerase.
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       CLASSIFICATION  OF  ENZYME
CLASS 1:
Oxidoreductases
Ex: LDH , ADH
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CLASS 2:
Transferases
Ex: glucose +ATP-------> glucose -6-Phosphate
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CLASS 3:
Hydrolases
Ex: glucose-6-Phosphate
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CLASS 4:
Lyases
Ex: Fumarase
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CLASS 5:
Isomerases
Ex: Retinol isomerase
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CLASS 6:
Ligases
Ex: DNA ligase

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MICHAELIS-MENTEN Equation:-----
 
              Vmax[S]
      Vo=----------------
            Km + [S]
(This is called michaelis menten equation)
(MME)
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PROPERTIES OF ENZYME OR FACTORS OF ENZYME KINETICS :----

1)Enzyme concentration
2)Presence of activator
3)Presence of inhibitor
4)Substrate concentration
5)Product concentration
6) Temperature
7)PH
8)Covalent modulation
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ISOENZYME :-
The multiple forms of an enzyme catalysing the same reaction are isoenzyme or isozyme.
Ex:-
LDH1
LDH2
LDH3
LDH4
LDH5
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RIBOZYMES: --
Ribozymes ate RNA molecules .
We know, all enzymes are protein in nature, but Ribozymes are non protein in nature.
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        ENZYME  INHIBITION 
There are three categories of Enzyme inhibition.
1)Reversible inhibition
2)Irreversible inhibition
3)Allosteric inhibition
          Reversible inhibition:
          There are three types-----
           a)Competitive inhibition
           b)Non-competitive inhibition
           c)Uncompetitive inhibition

     
                   THE END