Anabolism and catabolism can be viewed as two sides of the same coin. The connection between them can be viewed as ATP. Catabolism is the breakdown of molecules and releases energy to form ATP by adding a phosphate to ADP. The ATP produced by the breakdown of molecules can then be used to build up new molecules in the process known as anabolism. ATP is the energy molecule used for all cellular functions and without sufficient ATP the organism will not survive.
The initial breakdown of glucose is through glycolysis. The end product of glycolysis is pyruvic acid which can be decarboxylated to form acetyl-CoA which enters the Krebs cycle.
The major consideration is the overall amount of ATP that can be produced. In aerobic metabolism each glucose molecule can generate 38 molecules of ATP, while anaerobic metabolism generates only 2 ATP’s for each glucose molecule that is metabolized. The benefit of anaerobic respiration is that more un-oxidized glucose fragments can enter biosynthetic pathways per glucose used.