Question

Abrin and ricin are secondary metabolites of some plants. These secondary metabolites are
A. Lipid in nature
B. Proteins in nature
C. Carbohydrate in nature
D. Glycolipid in nature

Answer 1

Hint: Metabolites are defined as the biomolecules which are fairly smaller in size in comparison to large biomolecules such as proteins and nucleic acids. It contains all the chemical reactions that happen inside the body of an organism. Mainly metabolites are naturally occurring but, we can also generate them artificially for industrial and pharmaceutical aims.

Complete answer:
Any substance that involves metabolism is known as metabolites, also regarded as the by-product of a metabolic process. They are divided into two major types mainly: Primary metabolites (lactic acid, carbohydrate, amino acid) and Secondary metabolites (alkaloids, phenolic, sterols, steroids and essential oils). Primary metabolites are those that are involved directly in the growth, reproduction and metabolism of an organism. On the other hand, secondary metabolites are those that are not involved in any activity or they are the residue of primary metabolites. Abrin and ricin belong to toxic species of the secondary metabolites. Abrin is a kind of ribosome that inhibits proteins such as ricin. It is a toxin that is present inside the seeds of castor oil plants, which are proteinaceous. Abrin inhibits another toxin named pulchellin. It is a toxin that exists inside the seeds of Abrus pulchellus.

So, the right answer is Option B i.e. Proteins in nature.

Note: Primary metabolites are crucial for the survival and fecundity of living beings. However, secondary metabolites are not as much important but their scarcity causes damage to living beings. Primary metabolites are not species-specific or may be similar in some living beings while the secondary metabolites are species-specific. So they must be distinct in distinct organisms.