Question

Which is the most abundant protein on earth?
A. Catalase
B. RuBisCO
C. Amylase
D. None of the above

Answer 1

A protein, present in all living organisms, is a highly complex substance. Proteins are of tremendous nutritional value and are actively involved in chemical processes that are life-critical. The abundant proteins are ones that are present in our environment in the abundant composition and are mainly necessary to turn the raw form into some useful form needed for plants and human beings.

Complete answer: In Peroxisome and Glyoxysome, the enzyme catalase tends to occur. In most living organisms, like bacteria, animals, and plants catalase enzymes are observed. Its main function is to accelerate the breakdown of hydrogen peroxide into water and oxygen and thus protect the cell from oxidative damage from reactive oxygen species.
-RuBisCO refers to Ribulose-1, 5-bisphosphate carboxylase, or oxygenase is still the most numerous proteins found on the Earth, and therefore is concerned in the mechanism of carbon fixation through which plants, via the photosynthesis process, turn atmospheric carbon dioxide into their food sources, such as glucose.
-RuBisCO is known to be the most abundant enzyme on Earth, and among the most important for survival, undoubtedly. This is the only net carboxylase which humans are aware of, the only protein which can in single-step help accelerate the net fixation of inorganic carbon into organic molecules.
-Amylase is the enzyme that catalyzes starch hydrolysis into glucose. Amylase is a digestive enzyme that acts in food on starch, splitting it into simpler molecules of carbohydrate. The enzyme is produced in two sites.
Hence, the correct answer is option B, i.e., RuBisCO.

Note: Ribulose 1,5 bisphosphate (RUBP) is the atmospheric $C{{O}_{2}}$ acceptor in the citric acid cycle. Six carbon dioxide molecules bind to six Rubisco molecules to make twelve 3-molecules of phosphoglyceric acid (3-PGA) during its early Calvin cycle carboxylation stage, which is the first stable product of the process. The catalyst Ribulose bisphosphate carboxylase, usually referred to as RuBisCO, enhances this reaction.