10 Functions of Enzymes | Their Role in the Body with Examples

Enzymes, as we know, are the biocatalysts which enhance the rate of reaction.

They have a diverse role in the body as they are involved in the process of most biochemical reactions.

There are many types of enzymes like those which help in the breakdown, synthesis, reduction, oxidation, hydration, etc.

Enzymes are present in almost all of the body organs, tissues, and cells.

So their function is involved in all the 12 body systems in some or other way.

Function of Enzymes

Enzymes are involved in critical body functions like

  1. Digestion
  2. Metabolism
  3. Blood pressure control
  4. Excretion in kidney
  5. Blood clotting
  6. Nervous system control
  7. Repair and wound healing
  8. Reproduction
  9. Immunity and body defense
  10. Secretion.


Enzymes are the key molecules that process digestion in the body.

Enzyme amylase breaks down carbohydrates to simpler forms like glucose

Protease enzymes break down proteins to peptides and amino acids.

Enzyme lipase help in breaks down lipids to fatty acids and glycerol.

Nucleases enzymes catalyze the breakdown of nucleic acids

Due to this breakdown, they are easily absorbed into the bloodstream.


In simple terms, metabolism has two parts viz. anabolism and catabolism.

Anabolism is the synthesis of macromolecules from smaller ones. While catabolism is breakdown of larger molecules into smaller and simpler forms.

This metabolism is an important process to remove toxic waste from our body. When we consume so many foods and beverage items, they are broken down and excreted in urine or another route.Functions of Enzymes

This breakdown is done by many enzymes in the liver.

Similarly, excess glucose in the blood is converted into glycogen by the enzyme glycogen synthase and stored in the liver.

The liver is the major organ where most of the function occurs due to many enzymes.

It is the only organ with the highest number of enzymes and its dysfunction can be easily diagnosed by blood enzyme tests. Enzymes play a crucial role in metabolism.

Blood pressure control

The pressure of blood in the vessels is controlled by the hormone angiotensin from the renin-angiotensin system.

When the blood pressure is low, cells in the afferent arteriole of the nephron release the enzyme renin.

This renin converts the plamsa protein angiotensinogen to angiotensin-I.

This angiotensin-I is converted to angiotensin-II by an enzyme angiotensin-converting enzyme. This angiotensin-II is a potent vasoconstrictor which enhances the blood pressure.

Inhibition of this enzyme helps decrease the blood pressure in high blood pressure patients.

Excretion in the kidney

Excretion through the kidney is done by nephron. Nephron filters the blood and also the loop of it secretes few substances. Some enzymes are present on the nephron which prevent the excretion of useful substances like amino acids, polysaccharides, by breaking them and help in reabsorption. Ex: y-Glutamyl transpeptidase, leucine aminopeptidase, cysteine aminopeptidase, etc.

Also, carbonic anhydrase is the major enzyme that helps in the excretion of acid and reabsorption of bicarbonate.

There is also a sodium-potassium ATPase enzyme which helps to regulate sodium and potassium levels in the body.

Blood clotting: Clotting is a protective feature to prevent loss of blood in case of injury. This is a part of blood hemostasis. Thrombin is the enzyme that activates clotting factors and enables coagulation. It specifically converts fibrinogen to fibrin thereby forming insoluble clot strands.

Nervous system control: Nervous system regulates the whole body and physiology. Neurotransmitters are substances that help in the process. These neurotransmitters once released would help in nerve conduction and other functions. Their action is terminated once they are broken down by enzymes. For example, neurotransmitter acetylcholine acts on nicotinic receptors and is broken down by acetylcholine esterase enzyme. If it is not broken there would be persistent effects like seen in pesticide poisoning.

Repair and wound healing: Proteolytic enzymes are also involved in the wound healing process. They help to breakdown the necrotic debris of tissue and enhance new cell formation leading to wound healing.

Reproduction: Sperm is a part of the male reproductive system. The male gamete unites with the ova in the uterus. This sperm when released travels through the uterine tissue and reaches the ova.

Functions of Enzymes
Image by: Memorial University of Newfoundland

An enzyme namely hyaluronidase is released from the sperm tip (acronym) and this helps in tearing and penetration of sperm through the tissue to reach the ova. Without this enzyme, it would not be possible for the sperm to reach ova and fertilize. Sperm lives in the female reproductive tract for 48 hours once released from man.

Body defense: Lysosomal enzymes are helpful in the destruction of harmful microbes entering into the body. The saliva in the mouth kills microbes from food by the action of this enzyme. Similarly, macrophages at a type of WBC cells also engulf foreign microbes. There these microbes are digested by lysosomal enzymes. Thus enzymes also help in body defense and are part of immunity.

Secretion: Enzymes are also responsible for a few secretions in the body. For example, an enzyme called Proton potassium ATPase enzyme is involved in the secretion of gastric acid (HCl) in the stomach which aids in digestion. In the case of acidity, physicians prescribe drugs that can arrest this enzyme and thereby inhibit acid secretion leading to a decrease in acidity.

Respiration: Enzymes are also helpful in the physiology of respiration. There is an enzyme namely carbonic anhydrase in the red blood cells. This enzyme helps to convert carbon-dioxide to carbonic acid and bicarbonate ions.

Besides these enzymes help in detoxification of the body by metabolizing harmful substances leading to their excretion from the body.

Enzymes are also responsible for the storage of food in the form of glycogen to cope up with starvation. Besides enzymes are also involved in the generation of the body energy in the form of ATP from ADP.

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