Question

Concanavalin A is
(a) An alkaloid
(b) An essential Oil
(c) A lectin
(d) A pigment

Answer 1

These are carbohydrate-binding proteins that are highly specific for sugar groups of other molecules and so cause agglutination of particular cells or precipitation of glycoconjugates and polysaccharides.

Complete Step by Step answer:
Concanavalin A is a secondary metabolite e.g. is a lectin, it has the property to agglutinate RBCs.

Primary metabolites	Secondary metabolites
These are required for basic metabolic processes.	These are derivatives of primary metabolites and are not required for the basic metabolic processes.
These are easily extracted from plants.	Their extraction from a plant is difficult.
They play a good form of roles during a plant.	They have a limited role in a plant.
They are found from the beginning of the lifetime of a plant.	They are found during a specific period of development of the plant.
These are found in all plants.	These are found in particular plant species.

So, the correct answer is, ‘A lectin.’

Note:
- Metabolites are intermediate end products of metabolism.
- Primary metabolites are essential for the right growth of microorganisms.
- Secondary metabolites are formed near the stationary phase of growth and aren't involved in growth, reproduction, and development.
- The metabolites are often utilized in industries to develop vaccines, antibiotics, isolate chemicals for organic synthesis, and to get amino acids.
- Metabolites are the intermediate products that are produced during metabolism, catalyzed by various enzymes that occur naturally within cells. Eg., antibiotics, and pigments. The term metabolism is usually used in the case of small molecules. The different functions performed by metabolites include; fuel, structure, signaling, catalytic activity, defense, and interactions with other organisms.
The metabolites are produced by plants, human beings, and microbes.