During the light-independent reactions of photosynthesis (Calvin cycle), what is the primary enzyme responsible for fixing carbon dioxide by attaching it to ribulose-1,5-bisphosphate?

💡 Solution & Explanation

RuBisCO functions as the primary enzyme in the Calvin cycle, catalyzing the crucial fixation of atmospheric carbon dioxide onto ribulose-1,5-bisphosphate within the chloroplast stroma. Enzymes like hexokinase operate in glycolysis, while ATP synthase generates ATP during oxidative phosphorylation and photophosphorylation. This carboxylation step is considered the most abundant biochemical reaction on Earth.