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

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

They have a diverse role in the body as they are involved in 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’s organs, tissues, and cells.

So their function is involved in all the 12 body systems in some or another 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 into peptides and amino acids.
  • Enzyme lipase help in breaks down lipids into 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.
  • In contrast, catabolism is the breakdown of larger molecules into smaller and simpler forms.
Functions of Enzymes
  • This metabolism is a necessary process to remove toxic waste from our bodies.
  • When we consume so many foods and beverage items, they are broken down and excreted in urine or another route.
  • 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

  • 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 that enhances 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 the nephron. This is to some extent facilitated by enzymes.
  • 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 excrete acid and reabsorb bicarbonate.
  • There is also a sodium-potassium ATPase enzyme that 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.
  • 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

  • The nervous system regulates the whole body and physiology.
  • 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 the 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 break down the necrotic debris of tissue and enhance new cell formation leading to wound healing.


  • 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 the body.
  • Similarly, macrophages at a type of WBC cells also engulf foreign microbes.
  • Thus enzymes also help in body defense and are part of immunity.


  • Enzymes are also responsible for a few secretions in the body.
  • For example, an enzyme called the 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.


  • 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 the detoxification of the body by metabolizing harmful substances leading to their excretion from the body.
  • Enzymes are also responsible for storing food in the form of glycogen to cope with starvation.

Besides, enzymes are also involved in the generation of body energy in the form of ATP from ADP.

Frequently asked questions and answers.

  1. What is the enzymatic function of restriction enzymes

    Restriction enzymes are meant to cut the DNA at specific lengths.
    In bacteria, these enzymes help to destroy DNA of bacteriophages (virus) and protect them.

  2. What is the function of ligase enzyme

    These enzymes help in the binding of two biomolecules by catalytic action.

  3. Why is homeostasis important for the function of enzymes?

    Homeostasis of the body temperature, pH, hormonal control is useful in the efficient function of enzymes.

  4. What is the function of cellulase enzyme?

    Cellulase enzymes help in the breakdown of cellulose and other polysaccharides.

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