In the catabolic pathway, there is break down of large molecules, for example, lipids, polysaccharides, nucleic acids and protein into small molecules such as fatty acids, monosaccharides, nucleotide and amino acids, respectively. Formation of protein, cholesterol and glycogen is the anabolic process, which is made from amino acids, acetic acid and glucose, respectively.
In skeletal muscle reaction, break down of glucose occurs into lactic acid, which is a catabolic reaction and occurs in an anaerobic environment.