Primary And Secondary Metabolites


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Ever wondered why living organisms are able to do what they do and how they’re able to do it? There are important chemical activities that occur in the bodies and cells of all living organisms of the living organism that allow for such activities to be possible. One word used for describe such activities is metabolism. It is the chemical process that results in the production of metabolites which help in the proper functioning of the living organisms.

These metabolites produced are of two types; primary and secondary metabolites. For the purpose of this post, we will be talking about both of these metabolites. First, what are these primary metabolites?

Do not think too much about this and do not think it is anything complex. You have heard of these things that make up primary metabolites over and over again but probably did not just know they are termed primary metabolites.

Primary metabolites are molecules or substances that are produced during the growth phase of living organisms. As they are very important for the living organisms, they play a role in development and physiological functions. Carbohydrates, amino acids and alcohols are some examples of primary metabolites. These metabolites help in giving the organism energy, repair of worn-out tissues and transport of some other important nutrients.

There are plant and human primary metabolites which play important roles in reproduction, respiration and photosynthesis. Not just naturally, these primary metabolites can be produced industrially. Vitamins, ethanol and citric acid.

Primary metabolites are produced in high quantities in living organisms and as such make them easy to extract. Because they are produced in large quantities and in the growth phases of living organisms, their basic molecular structures form part of the organism’s molecular structure.

The importance of primary metabolites has been widely studied and hence largely applied in industries and industrial microbiology. Alcohol alone is used in so many products and one thing you can largely attribute it to is fermentation. Alcohol is used in the fermentation of wine and beer among other things.

After talking about primary metabolites, let’s move our concentration to what secondary metabolites are.

As living organisms grow, they are constantly met with new challenges. Solutions have to be found to these challenges and for organisms like plants, chemical compounds are produced which allows them to be able to defend themselves. Therefore, secondary metabolites are the products of defense mechanisms developed by living organisms.

Secondary metabolites are not produced in the growth phase of living organisms as they are not involved in primary functions. They, unlike primary metabolites are do not play roles in the growth, reproduction and photosynthesis of humans, plants and even microorganisms. As a result, they are formed when the living organisms reach their stationary phase. That is, when they stop growing. They can be referred to as end products of primary metabolites.

Secondary metabolites are produced in much smaller quantities as compared to the primary metabolites. It makes them very difficult to be extracted. Their structures are not a part of the basic structure of the organism.

Examples of some of the secondary metabolites are phenolic compounds, steroids, flavonoids, among others. Antibiotics like erythromcyin and bacitracinare also examples of secondary metabolites.

From this, we have found out that, primary metabolites are more involved with the growth and development of living organisms and secondary metabolites are not. They have ecological functions.

Thank you.



It's fascinating to think about how living organisms have evolved defense mechanisms to adapt to changes in the environment. These secondary metabolites have proven to be invaluable to humans as some have medicinal properties which have helped us improve our health.