Question

Since respiration involves breakdown of substrates, the respiratory process has traditionally been considered a catabolic process and the respiratory pathway as a catabolic pathway. But is this understanding correct?

Answer 1

Part 1: Introduction
Respiration is a multistep process where breakdown (catabolism) as well as formation (anabolism) of new substances takes place. The process begins with glycolysis and ends with oxidative phosphorylation. This entire pathway that occurs during respiration is called respiratory pathway.

Part 2: Amphibolic pathways
Biochemical pathways in which both anabolism and catabolism occur is called an amphibolic pathway.

Part 3: Respiratory pathway is an amphibolic pathway
For instance during glycolysis breakdown or catabolism of glucose occurs. During fatty acid formation (anabolism) acetyl CoA is withdrawn from the respiratory pathway. Thus in the respiratory pathway both anabolism and catabolism occurs. Therefore, it is an amphibolic pathway.