Question

_____is the most abundant protein in the animal world and ____is the most abundant protein in the whole biosphere.
A. Collagen, RuBisCo
B. Collagen, keratin
C. Keratin, RuBisCo
D. Keratin, Collagen

Answer 1

Hint:- A protein, a highly complex material found in all living organisms. Proteins are of immense nutritional importance and are actively involved in life-critical chemical processes. The most abundant enzyme on Earth, and arguably one of the most important for life, is RuBisCO. It is the only net carboxylase that we know of, the only enzyme that can catalyse inorganic carbon net fixation into organic molecules in one step.

Complete answer:
A protein, a highly complex material found in all living organisms. Proteins are of immense nutritional importance and are actively involved in life-critical chemical processes. In the animal kingdom, collagen is the single most abundant protein. Since time immemorial, it has been subjected to various studies. There are several applications and they have been derived from various sources, such as land animals (mainly bovine and porcine) and birds. The outbreak of various diseases among land animals posed a threat to its use in our everyday life, while collagen sources are abundant. Around 30 percent of the proteins within the body are made up of collagen. These are tough and strong structures found throughout the body: in the bones, ligaments and tendons. In nature, collagen occurs exclusively in animals, especially in mammalian flesh and connective tissues. Collagen is a portion of the connective tissue that contributes to firmness, suppleness and constant skin cell regeneration in the skin. For skin elasticity, collagen is essential.
Most generally known by the shorter name RuBisCO, the enzyme ribulose-1,5-bisphosphate carboxylase / oxygenase. For photosynthetic organisms, Rubisco is ubiquitous and is considered the most abundant protein on earth. The large subunit of Rubisco, from a nutritional point of view, has an exceptionally ideal composition of essential amino acids among plant proteins. In the future, the Rubisco plant is therefore expected to be a major source of food protein.
Hence, the correct answer is (a) Collagen, RuBisCo.

Note:- Most of the difference from laboratory conditions in the ocean but not on land, where quantification of several more factors on a global scale is needed, can be explained by the lower ambient temperature and Rubisco not working at night.