Enzymes and Hormones

A descriptive view on Enzymes

The cell is a site of fascination as all the reactions inside it are responsible for carrying out major bodily functions. 

Enzymes find their position in cell biology as they are needed to carry out various functions such as wear and tear of tissues, replacement of old cells, and building new cells in the body. For carrying out all the biochemical reactions in the body, a phenomenon known as catalysis is required. Catalysis is required to speed up the biochemical reactions. Enzymes are naturally occurring catalysts.

Enzymes are mainly proteinaceous. Some enzymes are also made up of catalytic RNA molecules. Enzymes were discovered by a scientist named Jon Jakob Berzelius in 1835, and he also discovered their Catalytic property. James B Sumner discovered the first enzyme in its pure form. They have a high molecular weight up to 10000 to 2,00,000 da. They are composed of several amino acids joined together in a bond known as a peptide bond.

Though enzymes are catalysts, they require other substances to function properly. These substances are known as ‘ Co factors.’ Likewise, the enzymes need cofactors to work efficiently. Cofactors, along with the enzymes, are together known as the holoenzyme. They together form an active complex.

As per the theory put forward by Holum, he defined a cofactor as:

1. A coenzyme- A coenzyme is an enzyme that is a non-protein organic molecule joined loosely to the protein part of the enzyme.
2. A prosthetic group – A prosthetic group is an organic substance that is highly thermostable but is attached tightly to the protein part of the enzyme.
3. A metal ion activator- A metal ion activator is also a cofactor. Metals such as potassium, calcium, iron, magnesium act as metal ion activators.

Specificity of Enzymes

Enzymes are highly specific and work for different reactions differently.

As they are highly specific, based on their specificity, they can be further classified as:

1. Absolute Specificity- An enzyme can be specific for a particular biochemical reaction.
2. Group Specificity – Group Specificity refers to a group presence on which an enzyme works particularly. Several enzymes are specific for particular groups.
3. Linkage Specificity – Several enzymes work only when a particular type of bond is present.
4. Stereochemical Specificity – Several enzymes work only in the presence of a particular optical or stereoisomer.

Hormones a descriptive view

Hormones are heterogeneous in composition and their molecular size, chemical nature, and the types of pathways for their synthesis.

Some hormones are proteinaceous, while some hormones have functional groups in them.

Based on their chemical composition, hormones can be divided into several categories.

Chemical Nature of hormones

Based on the chemical composition of the hormones, they can be classified into six categories:

1. Steroid hormones- Sex hormones, also known as androgens, are a type of steroid hormone.
2. Peptide Hormones- Oxytocin and Vasopressin are peptide hormones as peptide bonds are seen in their molecular structure.
3. Amine Hormones- Amine hormones are amino acids’ derived hormones. Thyroid hormones are a type of amine hormone.
4. Protein Hormones – Insulin glucagon is a type of protein hormones
5. Glycoprotein hormone – Hormones bound to carbohydrates such as galactose are glycoprotein hormones. LH hormones are a type of glycoprotein hormone.
6. Eicosanoid hormones- These types of hormones, namely prostaglandins, are derived from arachidonic acid.

Major Differences Between Enzymes and Hormones

The major differences between Enzymes and hormones are:

1. Enzymes perform their actions on the site of origin, i.e. within the cells where their production occurs, whereas hormones are target-oriented. Therefore, they perform their actions away from their source of production.
2. Enzymes have a catalytic property and are referred to as ‘ Biological Catalysts.’ Hormones, on the other hand, are not catalytic. They are equally needed in a biochemical reaction.
3. Enzymes are mainly proteinaceous, but hormones can be made of proteins, amines, amino acids, etc.
4. Enzymes have a high molecular weight and are macromolecules. On the other hand, hormones are small molecules with a low molecular weight.
5. Enzymes cannot diffuse through the cell membrane, whereas hormones can cross the cell membrane and diffuse.
6. Enzymes can increase the rate of reaction, whereas a hormone can slow or increase the reaction rate.
7. Enzymes are produced within the cell, so they perform intracellularly. Hormones have a target action, requiring the bloodstream to carry them to the desired organ.
8. Enzymes’ time of action is very high, but hormones show their effect on the organs.

Conclusion

Both enzymes and hormones play an important role in regulating body functions. A cell can work with an enzyme and does not need a hormone. Both are needed for the proper functioning of the body’s biological reactions.