Question

Rubisco is

		the enzyme that fixes CO2 to RuBP
		a slow enzyme
		an enzyme that can catalyze two different reactions
		All of the above

Answer 1

Ans: The answer is 'All of the Above'

Explanation:

RuBisCO is an abbreviation for the enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase that plays the 1st major step in the process of carbon fixation in the Calvin Cycle.Carbon fixation is the process of converting atmospheric CO2 to energy molecules like glucose by pants and other organsims that synthesize energy through photosynthesis. In this process CO2 is converted into ribulose-1,5-bisphosphate (RuBP) through carboxylation or oxygenation process which is catalyzed by RuBisCO.RuBisCo has this most unique ability of surviving on its own.That is it doesn't necessarily requires a plant and can help in the process of decomposition even if the plant is dead.

Although RuBisCO plays a central role,the slow speed of its working makes it inefficient too.While most of the enzymes processes around thousand molecules in a second,RuBisCo is able to catalyse just about three molecules of CO₂ per second.For compensating this slow pace of RuBisCO,plants build a lot of this enzyme and store it in the chloroplasts.This is why RuBisCO is also one of the most abundant enzyme on earth.

Hence, we can conclude that, RuBisCO is a slow enzyme that fixes CO₂ to RuBP and can do that by catalyzing two different reactions, carboxylation or oxygenation process.

Hence, the answer