The process of photosynthetic carbon fixation refers to the conversion of carbon dioxide into organic compounds during photosynthesis. This process primarily occurs in plants, algae, and certain bacteria, where sunlight energy is harnessed to transform CO2 and water into glucose and oxygen. The key steps include the Calvin cycle, where enzymes such as RuBisCO catalyze the fixation of CO2. This transformation is crucial for providing energy to the food web and reducing atmospheric CO2 levels, thus supporting ecosystem health.