This chapter explains the catabolism of sugar through glycolysis, the citric acid cycle, the pentose phosphate pathway, and eventual fate in alcoholic fermentation or oxidative phosphorylation, and provides examples of technical integration. Outgoing from these fundamental biochemical metabolic pathways, the biosynthesis of technically relevant metabolites such as citric acid, gluconic acid, and itaconic acid is discussed. In addition to their biosynthesis, biotechnical processes in industry for applications such as medicine, engineering, and the food industry are discussed with examples.