hi

hope you are doing well

RuBisCO is very important in biology and ecology because it catalyzes the primary chemical reaction by which inorganic carbon permanently enters the biosphere. RuBisCO is also the most abundant protein in leaves and the most abundant protein on Earth.

Hi Nasim

The most abundant protein in entire world is ribulose bisphosphate carboxylase/oxygenase i.e RUBISCo . It is also  the most important enzyme because it catalyses the carbon dioxide-fixing step in photosynthesis.

RuBisCO’s substrate is RuBP, which is regenerated as the Calvin cycle turns . But yes it also requires CO ₂ for the process to start. As the level of CO ₂ dissolved in the water in the leaf drops, the active site is less likely to be full.

I hope that it helps you

Thankyou