The respiratory pathway is considered to be a catabolic pathway because it involves only the breakdown of substrate for example in glycolysis the glucose is broken down to form pyruvate. But in the Tricarboxylic cycle (TCA cycle) the pyruvate is further broken down to Acetyl CoA, and this Acetyl CoA can also be synthesised to fatty acid whenever it is required for fatty acid metabolism or synthesis. Thus, During the TCA cycle, it is observed that both breakdown and synthesis of substrates occur. Therefore, the TCA cycle exhibits Amphibolic nature as it shows both catabolism and anabolism.