Factors affecting enzymatic activities
Enzyme are biological catalysts which increase the rate of bichemical reactions.
Factor affecting rate of reaction are as follow .
1.Enzyme concentration :
Enzyme molecules are larger than substrate molecules.In this system the substrate molecule are in relatively larger concentration as compared to the specific enzyme concentration ,the enzyme catalised reaction will be attened maximum speed .Further addition of substrate will have no effect on the reaction because all the active site of enzyme molecule have been saturated.Now,if the enzyme concentration increased and the substrate concentration is relatively higher in the system ,the rate of reaction will be increased .Again increase in the enzyme concentration will increase the rate of reaction ,but the time will be come when the rate will not increase due to the limiting effect of substrate concentration .Therefore enzymatic reaction is directly proportional to the concentration of enzyme .
2.Substrate concentration :
If the enzyme concentration is fixed and the substrate concentration is relatively higher then the velocity of reaction is increase to its maximum .If the substrate concentration is relavitely low as a particular enzyme concentration ,the reaction proceed but as a slow rate ,because the active site of only few enzyme molecule undergo no reaction due to the shortage of the substrate molecule .If the concentration of substrate is beyond the limit ,when all the active of enzyme molecule have becomes saturated ,the reaction will becomes constant without accelerating the velocity .
3.Temperature:
Temperature plays vital role in enzyme activities .In general the rate of enzymatic reaction increase with the rise of temperature upto 37°c but it decline further increase of temperature .So 37°c is the optimum temperature for enzyme activity .At 0°c or below 0°c the enzyme becomes inactivated ,but they are not destroyed .At low temperature ,the enzyme is preserved temporarily in as inactive site.This is the reasons why foods are reserved for long time in frozen state.At 60 to 70°c the enzyme are inactivated and destroyed .The destruction of enzyme at high temperature results incoagulation and denaturation.
4.PH:
Enzyme are sensative to the change in PH.Every enzyme required optimum PH for their maximum activity .Most of the intracellular enzyme function best around neutral PH.Pepsin is most effective in acidic medium ,while Trypsin shows its activity in alkaline medium .
Pepsin-2.0
Invertase-4.5
Maltase-7.0
Amylase-7.0
Trypsin-8.0
ATP-9.0
5.Ions:
Hydrogen ions concentration is the most important factor in the activity of all enzyme.The enzyme in the absence of particular cations remain inactive .In other words the enzyme required the particular cations for their complete structure .For example the enzyme phosphopyruvate hydrolase contain a loosly bound Mg++ cations without which it is inactive .Anions ate of less important in the enzyme activity.
6Accumulation of products:
Accumulation of reaction products inhibit the enzymatic activities mainly because the active site of enzyme are crowded by them and substrate molecule will have comparatively lesser chances of combining with the active site .If the concentration of reaction products becomes very high the reversed reaction occur.
7.Water:
Water is necessary for enzymatic activity because enzyme become only active after proper hydration of the cells.In absence of water no enzymatic activity will occur as seen on dry seed.
Inhibitions of enzymatic activities :
As general which inactevates the enzyme activity is known as inhibitor or poison or inactivator.In other words the chemical substances which reduced the velocity of a particular enzyme is known as inhibitors.
1.Enzyme concentration :
Enzyme molecules are larger than substrate molecules.In this system the substrate molecule are in relatively larger concentration as compared to the specific enzyme concentration ,the enzyme catalised reaction will be attened maximum speed .Further addition of substrate will have no effect on the reaction because all the active site of enzyme molecule have been saturated.Now,if the enzyme concentration increased and the substrate concentration is relatively higher in the system ,the rate of reaction will be increased .Again increase in the enzyme concentration will increase the rate of reaction ,but the time will be come when the rate will not increase due to the limiting effect of substrate concentration .Therefore enzymatic reaction is directly proportional to the concentration of enzyme .
2.Substrate concentration :
If the enzyme concentration is fixed and the substrate concentration is relatively higher then the velocity of reaction is increase to its maximum .If the substrate concentration is relavitely low as a particular enzyme concentration ,the reaction proceed but as a slow rate ,because the active site of only few enzyme molecule undergo no reaction due to the shortage of the substrate molecule .If the concentration of substrate is beyond the limit ,when all the active of enzyme molecule have becomes saturated ,the reaction will becomes constant without accelerating the velocity .
3.Temperature:
Temperature plays vital role in enzyme activities .In general the rate of enzymatic reaction increase with the rise of temperature upto 37°c but it decline further increase of temperature .So 37°c is the optimum temperature for enzyme activity .At 0°c or below 0°c the enzyme becomes inactivated ,but they are not destroyed .At low temperature ,the enzyme is preserved temporarily in as inactive site.This is the reasons why foods are reserved for long time in frozen state.At 60 to 70°c the enzyme are inactivated and destroyed .The destruction of enzyme at high temperature results incoagulation and denaturation.
4.PH:
Enzyme are sensative to the change in PH.Every enzyme required optimum PH for their maximum activity .Most of the intracellular enzyme function best around neutral PH.Pepsin is most effective in acidic medium ,while Trypsin shows its activity in alkaline medium .
Pepsin-2.0
Invertase-4.5
Maltase-7.0
Amylase-7.0
Trypsin-8.0
ATP-9.0
5.Ions:
Hydrogen ions concentration is the most important factor in the activity of all enzyme.The enzyme in the absence of particular cations remain inactive .In other words the enzyme required the particular cations for their complete structure .For example the enzyme phosphopyruvate hydrolase contain a loosly bound Mg++ cations without which it is inactive .Anions ate of less important in the enzyme activity.
6Accumulation of products:
Accumulation of reaction products inhibit the enzymatic activities mainly because the active site of enzyme are crowded by them and substrate molecule will have comparatively lesser chances of combining with the active site .If the concentration of reaction products becomes very high the reversed reaction occur.
7.Water:
Water is necessary for enzymatic activity because enzyme become only active after proper hydration of the cells.In absence of water no enzymatic activity will occur as seen on dry seed.
Inhibitions of enzymatic activities :
As general which inactevates the enzyme activity is known as inhibitor or poison or inactivator.In other words the chemical substances which reduced the velocity of a particular enzyme is known as inhibitors.
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