Starch and cellulose are common polysaccharides. Section 15.25 Organic acids are frequently metabolized through the citric acid cycle or through the glyoxylate cycle. Iso citrate lyase and malate synthase are the key enzymes of the glyoxylate cycle. Fats are metabolized by hydrolysis, by lipases, or phospholipases to free fatty acids. Enzymes called oxygenases introduce O 2 into a biochemical compound.
Many microorganisms can degrade aliphatic and aromatic hydrocarbons.
Catabolism aerobically involves the action of oxygenase enzymes. Anaerobic aromatic degradation proceeds by reductive rather than oxidative pathways. Draw the chemical structure for benzene. Do the same for benzoate. What fundamental difference exists in the anaerobic degradation of an aromatic compound compared with its aerobic metabolism.