The tricarboxylic acid cycle has 1 substrate level phosphorylation. The tricarboxylic acid cycle, also known as the citric acid cycle, the TCA cycle, and the Krebs cycle, is a cyclic reaction system in which mitochondria carry out enzymatic reactions, and it is the hub of all metabolic pathways in the body, such as sugar, fat, and protein. Substrate level phosphorylation is the process by which a substance unites some high-energy chemical bonds that can couple ATP or GTP during oxidation. Tricarboxylic acid cycle 1 substrate level phosphorylation step is succinyl CoA decomposition to synthesize succinic acid, succinyl CoA contains high-energy thioester bonds, in the generation of succinic acid, the generation of high-energy phosphate bonds, that is, the generation of GDP, this process is a reversible reaction. The tricarboxylic acid cycle undergoes one substrate level phosphorylation to produce GTP.