Enzyme catalysis is unique in its efficiency and high degree of specificity. The following characteristics are exhibited by enzyme catalysts :
(i) Most Highly Efficient : One molecule of an enzyme may transform one million molecules of the reactant per minute.
(ii) Highly Specific Nature : Each enzyme is specific for a given reaction, i.e., one catalyst cannot catalyse more than one reaction.
● For example, the enzyme urease catalyses the hydrolysis of urea only. It does not catalyse hydrolysis of any other amide.
(iii) Highly Active under Optimum Temperature : The rate of an enzyme reaction becomes maximum at a definite temperature, called the optimum temperature.
● On either side of the optimum temperature, the enzyme activity decreases.
● The optimum temperature range for enzymatic activity is `298-310K`. Human body temperature being `310 K` is suited for enzyme-catalysed reactions.
(iv) Highly Active under Optimum pH : The rate of an enzyme-catalysed reaction is maximum at a particular `pH` called optimum pH, which is between `pH` values `5-7`.
(v) Increasing Activity in Presence of Activators and Co-enzymes : The enzymatic activity is increased in the presence of certain substances, known as co-enzymes.
● It has been observed that when a small non-protein (vitamin) is present along with an enzyme, the catalytic activity is enhanced considerably.
● Activators are generally metal ions such as `Na^+`, `Mn^(2+)`, `Co^(2+)`, `Cu^(2+)`, etc. These metal ions, when weakly bonded to enzyme molecules, increase their catalytic activity.
● Amylase in presence of sodium chloride i.e., `Na^+` ions are catalytically very active.
(vi) Influence of Inhibitors and Poisons : Like ordinary catalysts, enzymes are also inhibited or poisoned by the presence of certain substances. The inhibitors or poisons interact with the active functional groups on the enzyme surface and often reduce or completely destroy the catalytic activity of the enzymes. The use of many drugs is related to their action as enzyme inhibitors in the body.
Enzyme catalysis is unique in its efficiency and high degree of specificity. The following characteristics are exhibited by enzyme catalysts :
(i) Most Highly Efficient : One molecule of an enzyme may transform one million molecules of the reactant per minute.
(ii) Highly Specific Nature : Each enzyme is specific for a given reaction, i.e., one catalyst cannot catalyse more than one reaction.
● For example, the enzyme urease catalyses the hydrolysis of urea only. It does not catalyse hydrolysis of any other amide.
(iii) Highly Active under Optimum Temperature : The rate of an enzyme reaction becomes maximum at a definite temperature, called the optimum temperature.
● On either side of the optimum temperature, the enzyme activity decreases.
● The optimum temperature range for enzymatic activity is `298-310K`. Human body temperature being `310 K` is suited for enzyme-catalysed reactions.
(iv) Highly Active under Optimum pH : The rate of an enzyme-catalysed reaction is maximum at a particular `pH` called optimum pH, which is between `pH` values `5-7`.
(v) Increasing Activity in Presence of Activators and Co-enzymes : The enzymatic activity is increased in the presence of certain substances, known as co-enzymes.
● It has been observed that when a small non-protein (vitamin) is present along with an enzyme, the catalytic activity is enhanced considerably.
● Activators are generally metal ions such as `Na^+`, `Mn^(2+)`, `Co^(2+)`, `Cu^(2+)`, etc. These metal ions, when weakly bonded to enzyme molecules, increase their catalytic activity.
● Amylase in presence of sodium chloride i.e., `Na^+` ions are catalytically very active.
(vi) Influence of Inhibitors and Poisons : Like ordinary catalysts, enzymes are also inhibited or poisoned by the presence of certain substances. The inhibitors or poisons interact with the active functional groups on the enzyme surface and often reduce or completely destroy the catalytic activity of the enzymes. The use of many drugs is related to their action as enzyme inhibitors in the body.