Enzymes and Metabolism: 9 Facts You Should Know

In this article let’s see about enzymes used in metabolism and nine facts about it.

Enzymes are proteins that act as catalysts to regulate metabolism and other chemical reactions in our bodies. It helps in both building up and breaking down substances.

Do enzymes regulate metabolism?

Enzymes and metabolism are interconnected as they help in regulating the metabolic process inside the body by increasing or decreasing the rate of reaction.

Metabolism is a chemical pathway that takes place between different cells. They are of two types:

  • Anabolism: the synthesis of larger molecules is known as anabolism
  • Catabolism: the process of breaking larger molecules into smaller molecules is known as catabolism

The metabolic reactions need a catalyst to increase the rate of a chemical reaction and it is done by the enzymes present inside the cell. The metabolic rate is either increased or decreased by the enzymes that can change the shape of the chemical inside the cell without changing itself.

enzymes and metabolism
Metabolism pathway from Wikipedia

How are enzymes involved in metabolism?

The enzymes act on a compound called substrate and they work in an organized manner in a form of a pathway and it is called a metabolic pathway. The metabolic enzymes have various benefits like storage and release of energy and are used in course of reproduction and respiration in humans.

The metabolic enzymes do a variety of cell functions that are necessary for survival, some of the functions are:

  • Homeostasis
  • Proteolysis
  • Digestion
  • Cellular respiration
  • Transcription

The metabolic enzymes are very crucial for metabolism as they allow the organisms to do desirable reactions and this requires energy.  During each step of the metabolic pathway, the enzymes transform the molecule to another form and such type of reaction is known as biosynthesis.

What are the enzymes involved in metabolism?

The enzymes that are involved in metabolism belong to different protein classes and they are:

  • Carboxylases – catalyzes the addition of carbon dioxide molecule into an organic substrate
  • Dehydrogenases – catalyzes reduction reaction by transferring hydrogen from substrate to a co-enzyme
  • Lipoxygenases  – this enzyme catalyzes the oxygenation of fatty acids like linolenic acid and arachidonic acid
  • Oxidoreductases-  the transfer of electrons from one molecule to another molecule is catalyzed by this enzyme
  • Kinases- the enzymes catalyze the transfer of phosphate between the substrates
  • Lysases- the addition and elimination reaction are catalyzed by these enzymes
  • Transferases- the transfer of amine, carboxyl, and carbonyl atoms from the donor substrate to the acceptor compound is catalyzed by the enzyme.

How do enzymes contribute toward metabolism?

Enzymes help to speed up a reaction; they act as a catalyst and help to break down larger compounds like proteins, fats, and carbohydrates into smaller molecules.

Where are enzymes used in metabolism?

The enzymes help break down large molecules like proteins, fats, and carbohydrates into smaller molecules. The enzymes function during digestion inside the stomach and the small intestine.

The enzymes are used in various metabolic pathways like:

Plant metabolism enzyme examples

The examples of enzymes that are used in plant metabolism are:

  • Hexokinase
  • Phosphohexose isomerase
  • Phosphofructokinase
  • Triose phosphate isomerase
  • G3P dehydrogenase
  • Phosphoglycerate kinase
  • Enolase
  • Pyruvate kinase
  • Rubisco ( Ribulose-1,5-biphosphate carboxylase)

Animal metabolism enzyme examples

The enzymes that are involved in animal metabolism are:

  • Acetyl- CoA carboxylase
  • Fatty acid synthase
  • Acyl-CoA oxidase
  • Lipase
  • Protease
  • Hexokinase
  • Enolase
  • Pyruvate Kinase
  • Phosphoglyceromutase

Fungi metabolism enzyme examples

The enzymes that help in fungal metabolism are:

  • Protease
  • Cellulase
  • Chitinase
  • Beta-glucosidase
  • Xylanase
  • Mannanase
  • Pectinase
  • Beta- fructofuranosidase

The metabolism in fungi produces two types of metabolites.

  1. Primary metabolitesLactic acid, Pyruvate, ethanol
  2. Secondary metabolites –Itaconic acid, Gibberellins (plant growth hormone), penicillin (antibiotic) lovastin, and cephalosporin.

The secondary metabolites of fungi are useful in pharmaceutical and other industries.

Bacteria metabolism enzyme examples

The enzymes used in bacterial metabolism are:

  • DNA gyrase
  • Topoisomerase IV
  • Polymerase
  • rRNA methyltransferase
  • Ligase
  • Serine racemase
  • Dihydrogenase
  • Phosphoethanolamine transferases


Enzymes are protein substances that act as a catalyst to speed up the metabolic reaction that takes place inside the cell. They are also used in various other functions like energy storage, respiration, and reproduction.

Shravanthi Vikram

Hi....I am Shravanthi Vikram, I have completed my master's in Bioinformatics and have 10 years of teaching experience in Biology. Let's connect through LinkedIn-https://www.linkedin.com/in/shravanthi-vikram-329a0a24

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