Most abundant protein on earth:

Explanation

The most abundant protein on Earth is RuBisCO, which stands for Ribulose-1,5-bisphosphate carboxylase/oxygenase. It is an enzyme that is found in all photosynthetic organisms, including plants, algae, and cyanobacteria. RuBisCO is responsible for the fixation of carbon dioxide into glucose during photosynthesis.