5 Flashcards
What are secondary metabolites?
Low molecular weight molecules produced by metabolic pathways outside of primary metabolism in organisms like bacteria, fungi, and plants.
what is the primary purpose of secondary metabolites in organisms?
Secondary metabolites are not essential for growth and survival but can improve an organism’s survival and adaptation to its environment.
How are bacterial and fungal secondary metabolites typically synthesized?
They are synthesized by biosynthesis gene clusters, known as operons in bacteria, which can be 10kbp-70kbp in size and contain central biosynthesis genes encoding large multidomain enzymes.
What are some bioactive properties of secondary metabolites?
Secondary metabolites can be antibiotic, cytotoxic, mutagenic, carcinogenic, teratogenic, immunosuppressive, or enzyme inhibitory.
In which industries are secondary metabolites used?
Secondary metabolites are used in pharmaceuticals (e.g., antibiotics), agrochemicals (e.g., antimicrobials and plant growth promoters), food and beverage (fermentation processes), biotechnology (enzymes), cosmetics (antimicrobials and pigments), environmental (biosurfactants for pollutant clean-ups), fragrance (volatile components), and drug research and development
Under what conditions do organisms produce secondary metabolites in the laboratory?
Organisms produce secondary metabolites in the laboratory when they are kept in varying stages of unfavorable conditions, such as incorrect pH, temperature, or oxygen levels, which stimulate the production of specific secondary metabolites to aid survival.
What are the four major classes of secondary metabolites?
The four major classes of secondary metabolites are polyketides (PKS), non-ribosomal peptides (NRP), terpenes (TP), and indole alkaloids (IA).
: How are the classifications of secondary metabolites determined?
Classifications are based on the biosynthetic pathways and enzymatic machinery used for their production. For example, PKS, NRP, TP, and IA are major classifications.
What are some specific subclassifications of bacterial secondary metabolites?
Subclassifications include Ribosomal Bacteriocins (e.g., Lantibiotics) and Lipopeptides, with Ribosomal Bacteriocins and lipopeptides often replacing TP and IA in bacterial secondary metabolite classifications.
What is the biosynthetic basis for the classification of PKS compounds?
PKS compounds are synthesized by large, multifunctional enzymes called polyketide synthases that add acyl units to the growing polyketide chain.
How is the structural basis for the classification of PKS defined?
PKS compounds are classified based on their modular nature, where each module is responsible for a specific enzymatic step, allowing for the production of complex and diverse molecules.
Which organisms produce PKS as secondary metabolites?
PKS secondary metabolites are produced by bacteria, fungi, and plants.
What are the common precursors used in the biosynthesis of PKS compounds?
PKS compounds are biosynthesized by the decarboxylative condensation of acetyl-CoA or malonyl-CoA, which are common precursors of primary metabolism. This process is similar to fatty acid synthesis.
What are some of the pharmacologically important activities associated with PKS compounds?
PKS compounds have various pharmacologically important properties, including antimicrobial, antifungal, antiparasitic, anti-tumour, and agrochemical activities.
Why are PKS compounds produced in high volumes by biotechnology companies?
PKS compounds are produced in high volumes by biotechnology companies due to their diverse properties and pharmacological importance, making them valuable for various applications.
