Write difference between primary metabolism and secondary metabolism.

Hint: Metabolism is a term used to describe all chemical reactions that are involved in sustaining the cells and the organism in their living state. Metabolism is closely related to diet and to nutritional availability. The secret to metabolism is nutrition. Metabolism pathways depend on nutrients that break down in order to generate energy.

Complete answer:
Metabolites can be classified into two major groups, namely, primary and secondary metabolites, based on their origin and function.
Microbial products developed continuously during the exponential phase of growth are primary metabolites and are involved in primary metabolic processes such as breathing and photosynthesis. They contain anabolic metabolism intermediates and end products, which are used by the cell as building blocks for important macromolecules. In industrial terms, amino acids, nucleotides, vitamins, solvents and organic acids are the most essential primary metabolites. Many of these metabolites are produced instead of chemical synthesis by microbial fermentation and isolation, since the fermentations are economically efficient and produce isomeric forms that are biologically useful.
Compounds formed by an organism that are not required for primary metabolic processes are microbial secondary metabolites, although they may have important ecological and other functions. The prolific sources of novel secondary metabolites continue to be streptomycetes and associated actinomycetes. Antibiotics, pigments, pollutants, effectors of ecological rivalry and symbiosis, pheromones, enzyme inhibitors, immunomodulating agents, receptor antagonists and agonists, pesticides, antitumor agents and animal and plant growth promoters are microbial secondary metabolites. Secondary metabolites are derived from pathways that include primary metabolites. Secondary metabolites are also deemed to be the end products of primary metabolites.

Note:
Among the simplest biotechnological products, primary metabolites such as amino acids, organic acids, or nucleosides are widely used as raw materials for other processes, such as fermentation or chemical synthesis. They are rarely used as medicinal compounds, but they are widely used as dietary supplements or flavouring agents. Fungal secondary metabolites are a significant source of medically useful compounds, from antibiotics such as penicillin to the anti-cholesterol compound lovastatin.