7. What is Amino Acid Pool?What is Amino Acid Pool?
7
The free amino acid content distributed
throughout the extracellular fluid
Quantitatively, it is about 100 gm in
an adult individual.
50% : Glutamate & Glutamine
10% : EAA
40% : Other AAs
9. Intermediary metabolism of AminoIntermediary metabolism of Amino
acidacid
9
Anabolism Catabolism
Synthesis of:
NEAA
Protein
NPN subs
Urea from NH3 via
urea cycle
Glucose, glycogen
FA, fat, steroid,
ketone bodies
Transamination
Deamination & removal
of NH2 group as NH3
Catabolism of AA C-
skeleton & synthesis of
glucose, FA, steroids,
ketone bodies, etc.
Oxidation of AA C-
skeleton via TCA cycle
11. What is Transamination?What is Transamination?
11
It is the transfer of NH2 group from an
AA to a keto acid with simultaneous
production of a corresponding keto
acid & AA respectively.
Remember,
No free NH3 is produced here
Only transfer of NH2 group occurs
12. 12
Amino acid participating
in transamination
Keto acid participating
in transamination
All Amino acids except :
Lys
Thr
Pro
Three keto acids
mostly participates:
α- ketoglutarate
Oxaloacetate
Pyruvate
15. Site of TransaminationSite of Transamination
15
Cytoplasm of:
Liver
Kidney
Heart
Sk. Muscle
Brain.
16. Coenzyme needed for TransaminationCoenzyme needed for Transamination
16
Pyridoxal phosphate:
Acts as an intermediate carrier of an
NH2 group.
17. Importance of TransaminationImportance of Transamination
17
Funneling of NH2 group of diff AAs
ultimately to α-KG :
To form Glu which is the major AA
that undergoes oxidative deamination.
Biosynthesis of NEAA
Formation of keto acid of an amino
acid:
Keto acid (carbon skeleton of AA)
later on can be catabolized/oxidized
18. 18
Provides a link b/w carbohydrate,
protein & fat metabolism:
Because, the keto acids generated by
transamination of AA can form
compounds common to their metabolic
cycle.
20. What is Deamination?What is Deamination?
20
Removal of –NH2 group from an AA in
the form of “free NH3 “
with simultaneous formation of its
corresponding keto acid.
21. AA unique in the process of DeaminationAA unique in the process of Deamination
21
Glutamate
Because,
it undergoes rapid oxidative
deamination catalyzed by
Glutamate dehydrogenase
(an active dehydrogenase)
27. 27
Sources of NH3 Fates of NH3
Catabolism of :
Amino acid
Purine & Pyrimidine
Bacterial degradation
of urea into NH3 by
bacterial urease in
intestinal lumen
Formation of :
Urea (Urea cycle)
Glutamate &
Glutamine in liver,
kidney, muscle, brain
Excretion of NH3 with
urine as NH4+ salt
28. 28
Glutamine :
The temporary non-toxic
storage & transport form of
NH3.
NH3 + α-KG Glutamate
Glutamate + NH3
Glutamine
34. Inborn error of protein metabolismInborn error of protein metabolism
34
Alkaptonuria
Homocystinuria
Phenylketonuria
Albinism
Maple syrup urine disease