Transamination & Deamination of
amino acids

1. TRANSMISSION:

The transfer of an amino group (-NH2) from an amino acids to
keto acid is known as transmission.  This
reaction involves  reversible  transfer 
of  a pair  of 
amino  acids  and  a
pair  of 
keto  acids  catalyzed 
by a  group  of 
enzymes transaminases (Amino transferases). This process is
predominantly in liver.

Pyridoxal phosphate is the co-enzyme essential for the
transaminase activity. All the amino acids except lysine, proline hydroxy proline
and theramine can participate in the transmission reaction.

The keto acids participating in the transamination reaction
are only three namely 2 -ketogluturic acid, oxaloacetic acid and pyruvic acid.

2. DECARBOXYLATION:

Decarboxylation is the removal of carboxyl group (-COOH)
from an amino acid to form amine with removal of CO2 is called as
decarboxylation.  These are catalyzed by
the enzyme decarboxylase which requires pyridoxal phosphate as co-enzyme.
Decarboxylase enzymes are available in liver, kidney and brain.

3. DIAMINATION:

Deamination means removal of amino group from amino acid in
the form of NH3. The ammonia liberated is diverted from urea synthesis. The
remaining carbon skeleton of amino acid is catabolised to keto acid. 

Diamination can be:

(2) Oxidative, (2) Non-oxidative

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