Catalysis is a phenomenon in which the rate of the reaction is altered, and the substance used to accelerate remains unchanged regarding quantity and chemical properties. The substance used to change the speed of the reaction is called a catalyst. Enzymes are a type of catalysts which are responsible for increasing the rate of reaction in plants and animals. The catalysis in which enzymes act as a catalyst is called enzyme catalysis.
Enzymes are complex compounds which are made up of nitrogen. Animals and plants produce These compounds. Enzymes are proteins which have high molecular mass and form a heterogeneous mixture when dissolved in water. These proteins act very efficiently and are responsible for various reactions which occur in the body of living beings. These proteins can also be called as biochemical catalysts and the catalysis as biochemical catalysis.
Characteristics of enzyme catalysis:
- A single molecule of this catalysis can transform a million molecules of the reactant per second. Hence it is highly efficient.
- These biochemical catalysts are unique in nature i.e. the same catalyst cannot be used in more than one reaction.
- The effectiveness of a catalyst is maximum at its optimum temperature. The activity of the biochemical catalysts declines at either side of the optimum temperature.
- Biochemical catalysis is dependent upon the pH of the solution. A catalyst works best at an optimum pH which ranges between 5-7 Ph values.
- The activity of the enzymes usually increases in the presence of a co–enzyme or an activator such as Na+, Co2+ The rate of the reaction increases due to the presence of a weak bond which exists between the enzyme and a metal ion.
Mechanism of enzyme catalyst:
Catalysis with enzyme as a catalyst
The enzyme consists of a number of cavities which are present on the outer surface. These cavities possess groups such as -COOH, -SH, etc. These centres are called as the active centre of the biochemical particle. The substrate which has the opposite charge of the enzyme fits into the cavities just as a key fits into a lock. Due to the existence of the active groups, the complex formed decomposes to give the products.
Hence this happens in two steps:
Step1: Combining of enzyme and the reactant
\(E + R \rightarrow ER\)
Step 2: Disintegration of the complex molecule to give the product
\(ER \rightarrow E + P\)
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