Catabolic pathways break down molecules to release energy, while anabolic pathways use energy to create new molecules. Both types of pathways are important parts of an organism's metabolism.
Cellular respiration is an important catabolic pathway necessary for the creation of ATP molecules. ATP is a molecule high in energy vital to the work done by cells. Cellular respiration involves the breakdown of glucose, a six-carbon sugar, into two three-carbon molecules. In the process, ATP molecules are produced that provide energy for further reactions in other systems.
The building of proteins utilizes some of the ATP produced through cellular respiration. Proteins are built through the linking of amino acids into chains called polypeptides. Each amino acid links to the chain using one ATP molecule. Bone-building cells use ATP in the production of calcium phosphate crystals. These crystals incorporate into the matrix of bones to strengthen them.
A fine balance exists between catabolism and anabolism in the body. The body must take in enough precursor molecules to be broken down by catabolism, so catabolic pathways can produce the energy required for the building and reparation needs of cells. Studies suggest these metabolic pathways are inextricably linked to human circadian rhythms, explains the Cell Press journal.