“Metabolites are intermediate products of  cellular metabolism catalyzed by various enzymes that naturally occur within the cells.”


Table of Contents

  1. Primary Metabolites
  2. Secondary Metabolites

What are Metabolites?

Metabolites are the intermediate products produced during metabolism, catalyzed by various enzymes that occur naturally within cells. Eg., antibiotics, and pigments. The term metabolites are usually used for small molecules. The various functions of metabolites include; fuel, structure, signalling, catalytic activity, defence and interactions with other organisms.

The metabolites are produced by plants, humans and microbes.

Also Read: Metabolites and Biomacromolecules

Plant Metabolites

Plant metabolites are of two types:

  • Primary Metabolites

  • Secondary Metabolites

Primary Metabolites

These are the chemical compounds produced during the growth and development, processes. They are also involved in the primary metabolic processes of respiration and photosynthesis. The primary metabolites are formed in the growth phase. They maintain the physiological functions of the body and are known as central metabolites. They are the intermediate products of anabolic metabolism, which are used by the cells for the formation of essential macromolecules.

Amino acids, vitamins, organic acids, are some of the primary metabolites produced industrially. Alcohol is the major primary metabolite produced on a large scale, industrially.

Also Refer: Amino Acids

Secondary Metabolites

These compounds are produced by the organisms that are not required for primary metabolic processes. However, they can be important ecologically or otherwise. Secondary metabolites are considered to be the end products of primary metabolites because they are derived by the pathways in which the primary metabolites involve.

For eg., antibiotics, toxins, pheromones, enzyme inhibitors, etc. Streptomycetes and related actinomycetes are the sources of novel secondary metabolites.

Differences between Primary and Secondary metabolites

Primary Metabolites Secondary Metabolites
Required for growth and maintenance of cellular function. Involved in ecological functions.
Occurs at the growth phase. Occurs at the stationary phase.
Produced in large amounts and easy to extract. Produced in small amounts and difficult to extract.
Same in every species. Different in every species.
Perform physiological functions in the body. Derivatives of primary metabolites.
Eg., carbohydrates, vitamins, ethanol, lactic acid. Eg., Phenolics, steroids, antibiotics, pigments.

Human Metabolites

Humans have 2500 metabolites. Prostaglandin produces a metabolite Arachidonic acid. Both the molecules have the same physical properties, functional groups and are linked by a series of enzyme-catalyzed reactions.

Cholesterol produces steroid hormones, catecholamines arise from the amino acid tyrosine.

All the information about the metabolites produced in the human body is freely accessible by an electronic database the Human Metabolome Database (HMDB).

Microbial Metabolites

Different microbes use different strategies to produce metabolites. These are useful in differentiating between different species of microorganisms.

Alcohol is one of the most common primary metabolites used for the fermentation- anaerobic respiration process for the production of wine and beer. Aspergillus niger produces citric acid widely used in food, pharmaceuticals and cosmetics industries.

Key Points Of Metabolites

  • Metabolites are intermediate end products of metabolism.
  • Primary metabolites are essential for the proper growth of microorganisms.
  • Secondary metabolites are formed near the stationary phase of growth and are not involved in growth, reproduction and development.
  • The metabolites can be used in industries to develop vaccines, antibiotics, isolate chemicals for organic synthesis and to obtain amino acids.

For more information on Metabolites and other related topics, keep visiting BYJU’S Biology website. You can also download the BYJU’S app for further reference.

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  1. Thank you for the research, it has made me learn the different types of metabolites