Functions of Enzymes

What are enzymes 

The enzymes are organic compounds ( mostly² proteins) produce by the living cells to speed up the spontaneously³ biochemical reactions in and outside the cells in living organisms. The process of speeding up chemical reactions is called catalysis,and the substances that speed up the reactions are termed catalytic components or catalysts. As the enzymes are secreted by living cells and they speed up chemical reactions, they are known as biocatalysts. The reactants in an enzyme _ catalyzed reaction are called the enzyme's substrates, and the substance produced in the reaction is termed product. The study of the composition and functions of the enzymes is known as enzymology ( enzyme + G. logos= study). A specialist in enzymes is called enzymologist.

 There are some nucleic acids that behave like enzymes. There are called ribozymes. One can depict an enzyme by a  line diagram.  An enzymes like any protein has a primary structure, i.e., amino acids sequence of the protein. An enzyme like any protein has the secondary and the tertiary structure. When you look at a tertiary structure you will notice that the backbone of the protein chain folds upon itself, the chain criss__ crosses itself and hence, many crevices or pockets are made. 

One such pocket is the 'active site' An active site of an enzyme is a crevice or pocket into which the substrate fits. Thus Enzymes through their active site ,  catalyse reactions at a high rate. Enzyme catalysts differ from inorganic catalyse in many ways, but one major temperatures and high pressures, while enzymes get damaged at high temperatures ( say above 40°C). Enzymes isolated from organisms who normally live under extremely high temperatures ( e.g., hot vents and sulphur springs), are stable and retain  their catalytic power even at high temperatures ( upon 80°__ 90°C). Thermal stability is thus an important quantity of such enzymes isolated from  thermophilic organisms. 

 Functions of  Enzymes :

The Functions of enzymes include:

1): Catalyse: Enzymes speed up chemical reactions by providing an alternative pathways with lower activation energy. This allow reactions to occur more rapidly, enabling essential cellular processes to take place efficiently. 

2): Specificity:Enzymes are highly specific in the reactions they catalyze. Each enzyme usually acts on a specific substrate, which is the molecule it interacts with and modifies during the reaction.The enzymes are specific in action. An enzyme may catalyze only a particular kind of reaction, or may even act on a particular substrate only. For example, the enzymes lactase catalyzes the hydrolysis of lactose and no other disaccharides. Specificity of an enzymes results from its unique 3_ dimensional shape.

3): Regulation: Enzymes control the rate of biochemical reactions and metabolic pathways. They can be regulated by factors such as pH, temperature, substrate concentration, and regulatory molecules. Enzymes regulation ensures that reactions occur at the appropriate time and in the necessary quantities. 

4): Metabolism: Enzymes play a crucial role in metabolic pathways, which are interconnected sets of chemical reactions that transform molecules into different forms, ultimately leading to the production of energy or the synthesis of biomolecules. 

5): Digestion: Enzymes in the digestive system breakdown large food molecules into smaller, more manageable forms that can be absorbed and utilized by the body.For example,  amylase breaks down starches, and lipase breaks down fats.

6): DNA Replication and Repair: Enzymes such as DNA polymerase and helicase are involved in DNA replication and repair processes, ensuring the accurate transmission and maintenance of genetic material. DNA acts as the genetic material in all organisms, except some viruses. New DNA is formed by replication of existing DNA.

7): Defense: Some enzymes, like lysosome in saliva, have antimicrobial properties and help prevent infection by breaking down bacteria cell walls. 

Overall enzymes are vital in promoting chemical reactions, maintaining cellular homeostasis, and enabling the various biological processes necessary for life.


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