Amphibolic cycle is
All other pathways such as beta-oxidation of fat or glycogen synthesis are either catabolic or anabolic. But TCA cycle is truly amphibolic (both catabolic and anabolic) in nature. There is a continuous influx (pouring into) (Fig.18.9) and a continuous efflux (removal) of 4-carbon units from the TCA cycle (Fig.18.8). In a traffic circle, many roads converge and traffic flows towards one direction. Since various compounds enter into or leave from TCA cycle, it is sometimes called as "metabolic traffic circle". Impoant anabolic reactions related with citric acid cycle are a. Oxaloacetate is the precursor of aspaate b. Alpha-ketoglutarate can be made into glutamate c. Succinyl CoA is used for synthesis of heme d. Mitochondrial citrate is transpoed to cytoplasm, where it is cleaved into acetyl CoA, which then is the staing point of fatty acid synthesis
Citric acid cycle
Glycolysis
Protein synthesis
Lipolysis
Metabolism of carbohydrate