Q. The most abundant enzyme in the living world is _____:
Answer: Rubisco
Notes: The abundant enzyme in the living world is Rubisco. It is a key regulator of non-steady state of photosynthesis. Ribulose-1,5-bisphosphate carboxylase oxygenase, most commonly known by the shorter name RuBisCO, is an enzyme that catalyses the first major step of carbon fixation, a process by which atmospheric carbon dioxide and water are converted to energy-rich molecules such as glucose, using sunlight.