This process is also known as the citric acid cycle. The Krebs cycle is a series of chemical reactions to generate energy by all aerobic organisms through the oxidization of acetate derived from proteins, fats, and carbohydrates into carbon dioxide. This cycle also provides additional precursors like NADH and amino acids. In this cycle, citric acid is first consumed and regenerated to complete the process. The process consumes water and acetate, reduces NAD+ to NADH, and finally produces carbon dioxide. This process allows the development of usable energy known as ATP.