The Chemical Reactions and Pathways Resulting in the Breakdown of Ornithine an Amino Acid Only Rarely Found in Proteins But Which Is Important in Living Organisms As an Intermediate in the Reactions of the Urea Cycle and in Arginine Biosynthesis.
Catalysis of a Biochemical Reaction At Physiological Temperatures. in Biologically Catalyzed Reactions the Reactants Are Known As Substrates and the Catalysts Are Naturally Occurring Macromolecular Substances Known As Enzymes. Enzymes Possess Specific Binding Sites For Substrates and Are Usually Composed Wholly or Largely of Protein But RNA That Has Catalytic Activity (ribozyme) Is Often Also Regarded As Enzymatic.
Catalysis of the Transfer of a Group E.g. a Methyl Group Glycosyl Group Acyl Group Phosphorus Containing or Other Groups From One Compound (generally Regarded As the Donor) to Another Compound (generally Regarded As the Acceptor). Transferase Is the Systematic Name For Any Enzyme of EC Class 2.