What is RuBisCO? Explain its role in C 3 and C 4 photosynthesis.

RuBisCO stands for ribulose 1,5-bisphosphate carboxylase-oxygenase. It is the first enzyme that is involved in the dark reaction to produce glucose molecules. In C3 and C4 plants, the RuBisCO enzyme catalyzes the carboxylation process in the mesophyll cells of C3 plants and bundle sheath cells of C4 plants.

What is RuBisCO? Explain its role in C 3 and C 4 photosynthesis.

RuBisCO stands for ribulose 1,5-bisphosphate carboxylase-oxygenase. It is the first enzyme that is involved in the dark reaction to produce glucose molecules. In C3 and C4 plants, the RuBisCO enzyme catalyzes the carboxylation process in the mesophyll cells of C3 plants and bundle sheath cells of C4 plants.

Give the importance of C 4 plants.

The importance of C4 plants: (i) C4 plants have Kranz anatomy(the plants have additional bundle sheath cells near the vascular bundle cells). Thus, C4 plants can avoid wasteful processes like photorespiration. (ii) They have high productivity than C3 plants.

Specify how a pentose phosphate is a CO 2 acceptor in the dark reaction of photosynthesis.

A pentose phosphate which is a CO 2 acceptor and takes part in the dark reaction or Calvin cycle is known as ribulose 1,5-bisphosphate (RuBP). RuBP accepts the CO 2 in the first step of the Calvin cycle and the presence of the RuBisCO enzyme. It undergoes carboxylation to produce two molecules of phosphoglyceric acid (PGA).

What are the steps that are common to C 3 and C 4 photosynthesis?

The common steps in C3 and C4 photosynthesis: (i) Both C3 and C4 photosynthesis involve dark reactions that take place in the stroma. (ii) Regeneration of RuBisCO takes place in both cycles. (ii) Carboxylation of Ribulose 1,5-bisphosphate occurs in the presence of enzyme RuBisCO to form 2 molecules of PGA.