Specificity of Enzyme: Types, Example and Mechanisms

A cell is defined as the structural, functional and biological unit of an organism. All living organisms are made of at least one cell.

• Every cell is made up of macromolecules of proteins, DNA and RNA.
• For the normal functioning of the body, the cell uses a biocatalyst called enzymes to increase the efficiency of the body. 
• Enzymes are responsible for the breaking down of substances found in the body.
• They have high catalytic power and substrate specificity.
• Enzymes are responsible for catalysing 5000 chemical reactions.
• The study of the field of enzymes is called enzymology.
• The efficiency of enzymes is increased by lowering the rate of activation energy.
• Specificity of enzyme is the property of enzymes that will help in the selection of choice of substrate.

Read More: Hormones

Key Terms: Enzyme, Proteins, Organism, Specificity of Enzyme, Cell, Activation Energy, DNA, RNA, Molecules, Substrate

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What is Enzyme?

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Enzyme is the process of breaking down cells and organs through an aseptic chemical process. 

• These are basically proteins that speed up the metabolism rate in the living organisms.
• It is also responsible for controlling the rate of reaction within the organism without changing the characteristics of enzymes.
• Activators are responsible for increasing the efficiency of enzymes.
• Most common example of enzymes includes washing powder used in households.
• It is also used in meat tenderizer machines to break down large chunks of meat into smaller pieces.

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Features of Enzymes

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Some essential features about enzymes are as follows:

• Enzymes are used as catalysts that will speed up the chemical reaction taking place inside the cells.
• It is said to work along with substrate found in the body; thus, relations between substrate and enzymes are important.
• The efficiency of enzymes is affected by temperature, pH and inhibitors.
• Enzymes are denatured when exposed to excessive heat. 

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Functioning of Enzymes

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The enzymes work on the principle of the lock and key model, which was proposed in 1894. It can work efficiently when the temperature is maintained at 37 degrees Celsius. 

Functioning of Enzymes

The enzymes work by binding the reactant molecules together. The process occurs in such a manner that bond breaking and forming occur more efficiently.

• An enzyme will grab one or more reactant molecules called substrates to catalyse a reaction.
• The area of the enzyme where the binding of substrates takes place is called the active site.
• When substrate combines with enzymes, it will form a final product called enzyme-substrate complex.
• The enzyme-substrate complex will leave the active site when it is fully developed.

It can be explained with the following reactions:

• Reactant (1) + Reactant (2) → Product
• Reactant (1) + Enzyme → Intermediate
• Intermediate + Reactant (2) → Product + Enzyme

Read More: Reproductive Health

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Specificity of Enzyme: Definition

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Specificity of Enzyme is defined as the process of choosing a substrate from a group of similar chemical molecules by the use of enzymes.

Enzyme Specificity

The enzyme specificity of a specific enzyme is one, as it has only one substrate.

• In the case of absolute enzyme specificity, it can catalyse only one chemical reaction.
• It can also be called the molecular identification process.
• The process defines the relationship between enzyme and substrate exhibiting complementary structural and functional properties. 
• It can also be used as a diagnostic and research tool.

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Example of Specificity of Enzyme

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Some examples of specificity of enzyme are as follows:

• One of the most common examples of specificity of enzyme is lactase. Lactase will act as an enzyme that will catalyse the hydrolysis of lactose. The process will create the compounds called glucose and galactose. Lactase will not react with any other sugar compound.
• Second example is thrombin which is used in blood clotting mechanisms and reacts with only one chemical reaction.

Read More: Two Kingdom Classification

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Different types of Specificity of Enzyme

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Specificity of Enzyme can broadly be divided into four categories, which are as follows:

• Absolute Specificity: It is a type of enzyme specificity in which enzymes will react with only one substrate.
• Group Specificity: As the name suggests, it is a type of specificity in which enzymes will react with the bond and group associated with the compound. For example, amino and phosphate groups.
• Stereochemical Specificity: In this category, enzymes will act not only on one substrate but also on the optical configuration of the compound.
• Linkage Specificity: This is a type of specificity in which enzymes will act on substrates that have the same chemical bond regardless of their molecular structure.

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Things to Remember

• A cell is the functional unit of all living organisms.
• Enzymes will use the cells as a biological catalyst that will speed up the chemical reaction.
• The enzymes depend upon the pH, temperature and inhibitors.
• Specificity of Enzyme is the process of selecting a substrate from a group of reactions.
• It is divided into four categories, namely Absolute Specificity, Group Specificity, Stereochemical Specificity and Linkage Specificity.

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