Ribulose bisphosphate carboxylase/oxygenase, commonly known as RuBisCO, is an essential enzyme found in plants, algae, and some bacteria. It plays a crucial role in the process of photosynthesis by catalyzing the conversion of carbon dioxide into organic compounds. This reaction is vital for producing the sugars that serve as energy sources for plants and, ultimately, for the entire food chain. RuBisCO can also catalyze a reaction with oxygen, leading to a process called photorespiration, which can reduce the efficiency of photosynthesis. Despite its inefficiencies, RuBisCO is one of the most abundant proteins on Earth, highlighting its importance in the global carbon cycle and ecosystem sustainability.