Biologically important amines vitamins

Amines, compounds in which one or more of the hydrogens of ammonia (NH3) have been replaced by an alkyl group, are among some of the most abundant compounds in the biological world. We will come to appreciate their biological importance as we explore the stmctures and properties of amino acids and proteins in Chapter 22 as we study how enzymes catalyze reactions in Chapter 23 as we investigate the ways in which coenzymes—compounds derived from vitamins—help enzymes catalyze reactions in Chapter 24 and as we learn about nucleic acids (DNA and RNA) in Chapter 26. 

Transaminases also belong to the group of transferases and catalyze desamination and amination reactions. Most amino acids are in equilibrium with the corresponding 0x0-carboxylic acid like alanine and pyruvate. The coenzyme of enzymatic transamination is pyridoxal-5 -phosphate 93, it is one of the most important coenzymes and is in effect the biologically active form of vitamin B6, which is converted to pyridoxamine 94 in this reaction. Besides transamination, pyridoxal-5 -phosphate 93 is also involved in decarboxylation and racemization processes. The aldehyde function of pyridoxal is reacting with the amine of an amino acid to form a Schiff base and thus invers-ing the acidity of the a-CH. The reversible transfer of an... 

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