Rubisco, or ribulose-1,5-bisphosphate carboxylase/oxygenase, is a crucial enzyme in the process of carbon fixation, catalyzing the first major step of converting atmospheric carbon dioxide into organic molecules during photosynthesis. Despite its essential role, Rubisco is relatively inefficient and can catalyze reactions with both carbon dioxide and oxygen, leading to photorespiration, which reduces photosynthetic efficiency.