6. FEATURES OF TRANSAMINATION
❑ Requires pyridoxal phosphate
❑ No free NH3, only transfer
❑ Reversible
❑ Responsible for syn.of non-essential aa
❑ It can divert excess aa towards energy generation
❑ The aminoacids undergo transamination to concentrate nitrogen into
glutamate
❑ All aa except lysine, threonine & proline/hydroxy proline undergo
transamination.
8. From transmination, the amino
groups generated are given to this.
Glutamate serves as collection
centre for NH2 groups
GDH
1. Zn –mitochondrial enzyme
2. Allosteric regulation
3. GTP,ATP inhibitors/GDP,ADP activators
4. Steroid/thyroid hormones inhibit
5. Protein rich meal,liver glutammate is elevated
13. METABOLISM OF AMMONIA
1. Formation of NH4
4. Disposal of NH4
Transamination,deamination,purines,
pyrimidines,by action of bacterial urease
Ammoniotelic-aquatic animals
Uricotelic-reptiles/birds
Ureotelic-mammals
2,3,5-next page
14. 2. TRANSPORT & STORAGE OF NH3:
• Conc of NH3- 10-20mg/dL(considerably low).
• NH3- immediately diverted to urea synthesis.
• Transport of NH3 between tissues & liver- Glutamine
or alanine.
• Glucose-alanine cycle
26. Functions of catecholamines
❑ Regulate carbohydrate & fat metabolism
❑ They stimulate breakdown of TAG/glycogen
❑ They cause increase in BP
❑ DOPA, Nor-Epinephrine- Neuro-transmitters in
BRAIN & Nervous system.
38. DEGRADATION OF GLYCINE:
1. Oxidative deamination- NH3, CO2, N5-N10 THF.
2. Glycine can form Serine.
3. Synthesis of special products:
• Purine ring
• Glutathione
• Conjugation reactions
• Heme next page
• Creatine
51. • Genetic disease caused by deficiency of branched
-chain aminotransferase
• Alpha keto amino acids, valine, isolucine and
Lucine will accumulated in the blood and excreted
in the urine (smells like maple syrup)
• If untreated, mental retardation and early death
Maple syrup urine disease
57. ❑ The urea cycle is a cycle of biochemical reactions that produces urea
(NH2)2CO from ammonia (NH3). Urea accounts 80-90% Nitrogen.
❑ Animals that use this cycle, mainly amphibians and mammals, are
called ureotelic.
❑ The urea cycle converts highly toxic ammonia to urea for excretion.
❑ This cycle was the first metabolic cycle to be discovered (Hans Krebs
and Kurt Henseleit, 1932), five years before the discovery of the TCA
cycle.
❑ The urea synthesized in the liver and transportd to the kidneys for
excretion in the urine.
Urea Cycle
Easily soluble
58.
59.
60.
61.
62.
63. Hypoalbuminemia-
Calcium
Tissue edema caused by-malnutrition(albumin syn )
Nephrotic syndrome( albumin lost through urine)
Liver cirrhosis( alb syn )
Chronic cardiac failure( hydrostatic pressure)
