G BHAGYARAJ ANCHAL Zoology Tutor 8281093200,8281094200

2. SUBMITTED BY,
BHAGYARAJ.G
I MSC ZOOLOGY
ST: STEPHEN’S COLLEGE PATHANAPURAM
AMINO ACID METABOLISM
& UREA CYCLE

3. WHAT IS BIOCHEMISTRY ?

5. PROTEINS
❑Proteins are the most abundant organic compounds that
constitute a major part of the body dry weight (10-12kg).
❑Our body gets sufficient amount of proteins from food
sources such as fishes, milk , egg , mixed nuts etc .
❑Protein metabolism is more appropriately learnt as amino
acid metabolism.
❑Each of the 20 amino acids undergoes its own metabolism
and perform specific functions.

7. AMINO ACID SYNTHESIS
DECARBOXYLATION
DEAMINATION
TRANSAMINATION

8. OVER VIEW OF AMINO ACID SYNTHESIS

9. TRANSAMINATION
❑The transfer of an amino group from an amino acid to a
keto acid is known as tansamination.
❑The energy (keto acid) that we get from transamination is
has various fates.
❑ Utilised to generate energy .
❑ Used for the synthesis of glucose.
❑ For the formation of ketone bodies.
❑ For the production of non-essential amino acids.

10. MECHANISM OF TRANSAMINATION

11. ❑ All transaminases require pyridoxal phosphate (PLP), a
co enzyme which is derived from vitamin B6
❑Here the transfer of amino group from Alanine is
trasferred to the co enzyme pyridoxal phosphate to form
pyridoxamine phosphate.
❑The amino group of pyridoxamine phosphate is then
transferred to the keto acid (alpha keto glutarate) to
produce a new amino acid (Glutamate) and the ezyme
pyrodoxal phosphate (PLP) is regenerated.
❑The transamination process is reversible.
❑There is no free ammonia (NH3) is liberated,only the
transfer of amino group occurs.

12. DEAMINATION
OXIDATIVE DEAMINATION
NON OXIDATIVE DEAMINATION
The removal of amino group from the amino acid is called
deamination. It is of two types:

13. OXIDATIVE DEAMINATION
❑Oxidative deamination is the liberation of free ammonia
from the amino group of amino acids coupled with
oxidation.

14. NONOXIDATIVE DEAMINATION
❑Non-oxidative deamination is the liberation of free
ammonia from the amino group of amino acids without
oxidation.

15. DE CARBOXYLATION
❑De carboxylation is the removal of CO2 from the
carboxyl group of amino acid and converts it to
corresponding amine.
❑It requires the enzyme decarboxylase, which is present in
liver,microorganisms of intestinal tract etc.
❑Pyridoxal phosphate acts as a co-enzyme here.

16. UREA - CYCLE
❑Ammonia which is synthesised during amino acid
metabolism is higly toxic. This toxic susbstance is
converted to non toxic urea and excreted from our body
through urine.
❑This can be explained through Urea-cycle which was
elucidated by Hans Krebs and Kurt Henseleit, hence it is
also called Krebs-Henseleit cycle.
❑The cycle takes place in mitochondria and cytoplasm of
the cell.