Question

_____ are the most abundant protein in the living world.
A) Ribozyme of plants and collagen of animals
B) RuBisCO of plants and collagen of animals
C) PEPcase of plants and keratin of animals
D) Alcohol dehydrogenase of plants and melanin of animals

Answer 1

Hint:This one is the short name of ribulose-1,5-bisphosphate carboxylase/oxygenase enzyme that incorporates CO$_2$ into plants during photosynthesis.


Complete answer:
The most abundant protein in the living world is RuBisCO.
>It works as a catalyzer in carbon fixation.
>You can find it in plants, algae, cyanobacteria, and certain other bacteria.
>Carbon fixation is the main chemical reaction responsible for inorganic carbon used for the formation of food.

The most abundant protein in the human body is collagen.
>It forms connective tissue.
>You can find it primarily in fibrous tissue, such as tendons, ligaments, and skin.
>It is a component of muscle, cartilage, bone, blood vessels, the cornea of the eye, intervertebral discs, and the intestinal tract.

Thus, the correct answer is option B i.e, RuBisCO of plants and collagen of animals.

Additional information: Ribozymes are also known as RNA molecules. It has a great ability to catalyze peculiar biochemical reactions such as RNA splicing in gene expression. Keratin is a type of fibrous protein, found in an animal's hair, skin, and nails. Melanin is the colour pigment that defines the colour of fur and hair in animals.

Note: The enzyme Rubisco contains about 30% of the total protein in a plant leaf. It can be considered as the most abundant protein on earth and a major sink for plant nitrogen. Rubisco is widely accepted as the ultimate rate-limiting step in photosynthetic carbon fixation.