Carbon Fixation: Pathways and Mechanisms

This lecture covers the process of carbon fixation, also known as CO₂ fixation, which is essential for converting carbon dioxide into organic carbon. The instructor begins by explaining the significance of carbon fixation for the planet, highlighting its role in providing food and energy through primary production. The lecture details various pathways for CO₂ fixation, including the Calvin-Benson-Bassham cycle, reductive citric acid cycle, and reductive acetyl-CoA pathway, among others. Each pathway is discussed in terms of the organisms that utilize them, the key enzymes involved, and the biochemical processes that occur. The instructor emphasizes the importance of autotrophs, which can be phototrophs or chemotrophs, in these processes. The lecture also includes a phylogenetic overview of the organisms involved in carbon fixation and the biochemical details of each pathway, providing a comprehensive understanding of how different organisms contribute to carbon cycling in various environments.