Primary and secondary Metabolites

 Primary and secondary Metabolites:

Thousands of organic biomolecules are present in the cells. These include monosaccharides ( simple sugars), disaccharides, Oligosaccharides, fatty acids, glycerols, lipids, phospholipids, sterols, amino acids, nitrogenous bases, nucleotides etc. These organic compounds are constantly utilized in various metabolic ( anabilic and catabolic) reactions occurring in the cells. Hence, these are termed as " metabolities' .In animal  tissue, all the categories of organic compounds are present. These are termed as primary metabolites.



   Primary metabolites are essential compounds that are involved in the basic metabolic processes necessary for the growth, development, and survival of an organism. They are typically produced during the active growth phase of an organism and are crucial for maintaining cellular functions. These metabolites are often universal across species and have important roles in energy production, biosynthesis of cellular components, and regulation of cellular processes. 
On the other hands, if we analyse plant, fungal or microbial cells, we would see thousands of compounds other than these primary metabolites.Seccondary metabolites are  compounds that are not directly involved in the fundamental growth and development of an organism but often play critical roles in ecological interactions and defense mechanisms. Some prominent ones are alkaloids, flavonoids, rubber, essential oils, antibiotics, coloured pigments  scents, gums, spices etc. These are called secondary metabolites.

      Primary metabolites have identifiable functions and these play known roles in normal physiological processes. On thr other hand, role or functions of all the secondary metabolites in host organisms are not properly understood at present. Many of them are useful to human welfare, e.g., rubber, drugs, spices, scents and pigments. Some secondary metabolites have ecological importance. 

Examples of Primary and secondary Metabolites includes :

Primary metabolites:

Amino Acids : Amino acids are small molecules that are the building blocks of proteins. Chemically, an amino acid is a molecule that has a carboxylic group and an amino group that are each attached to a carbon atom called the œ carbon.
   There are 20 types of Amino acids. These 20 amino acids can be classified as Essential and Non__ Essential amino Acida.

 ● Nonessential amino acids can be synthesized in the body, whereas essential amino acids must be obtained in the diet.

● There are 9 Essential Amino acids and 11 Non_ essential Amino acids. 

 Nucleotides:  Nucleotide form about 2% of the cell contents A nucleotide molecule is formed of a nitrogenous base , a pentose sugar and 1 to 3 phosphate groups. Nitrogen base is a pyrimidine ( thymine, cytosine or uracil), or a purine ( adenine or guanine). Nucleotides polymerise to form DNA and  RNA. They also form energy carriers, such as ADP and ATP, that provide ready for biological activities. They also take part in the formation of coenzymes such as NAD, NADP, FMN, FAD.

Carbohydrates: Carbohydrates are the key source of energy for most of the living organisms. In organisms, they normally occur as monosaccharide or polysaccharide compounds. Monosaccharides are simple sugars, polysaccharides are complex forms of sugar used for storage or structural purposes. 

Lipids: Lipids are large and diverse group of compounds that are soluble in non__ polar organic solvents like alcohol. These compounds include fats, oils, waxes and sterols. They are extensively found in cell membranes and they act as energy storage and signalling molecules. 

Organic Acids:  Involved in metabolic pathways and cellular regulation. 

Secondary Metabolites:

Alkaloids:  Bitter _ testing compounds found in plants, often acting as chemical defense against herbivores. 

Terpenoids: A diverse group of compounds found in plants, with roles in scent production and ecological interactions.

Flavonoids: pigments that give colour to flowers and fruits, also involved in attaching pollinators.

Phenolic Compounds : Act as antioxidants and contribute to definse against pathway and  stress.

The distinction between primary and secondary metabolites is not always strict, and some compounds can have roles in both essential metabolic processes and specialized functions,  depending on the context within the organism's life cycle and environmental conditions. Both types of metabolites are crucial for understanding the biochemistry, ecology, and potential applications of living organisms. 


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