The ppt explains the metabolism of Amino acids in our body. It is a topic from nutritional biochemistry

1. AMINOACID
METABOLISM
S.Malathi Varma
Assistant
Professor

3. GUTAMATE/GLUTAMINE- 50%
ESSENTIAL AMINOACIDS-10%

4. Protein
turnover

5. Transaminatio
n

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.

7. 1. OXIDATIVE
2. NON-
OXIDATIVE

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

9. FMN FMNH2
½
H20
catalase
Oxidative Deamination- By Oxidase

12. D-Aminoacids?

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

15. 3.
Functions
of
NH3
Non-essential Aminoacids, Purines,
Pyrimidines
Amino sugars, Aspargine
Acid—Base balance
5. TOXICITY OF NH3: self study

16. Metabolism of Individual Amino-acids:
1. Glycine
2. Plenylalanine/Tyrosine
3. Leucine
4. Methionine
5. Serine

17. Ketogenic
L,K
Both
F,I,Y,W
Glycogenic
A,R,D,C,N,G,H,P,M,S,Th,V
Classification of Aminoacids based
On Fate of Carbon skeleton

18. MATTVILPH
Y

19. PHE- ESSENTIAL AMINOACID
TYR- NON-ESSENTIAL AMINOACID
Sparing action of tyrosine on phenylalanine

22. Degradation of tyrosine/phenylalanine
PLP-pyridoxal phosphate

23. -Melanin
/ Tyrosinase

24. SYNTHESIS OF THYROID HORMONES

25. Catecholamines
CATECHOL
SYNTHESIS OF CATECHOLAMINES

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.

36. GLYCIN
E

37. GLYCIN
E
SERINE Serine hydroxy methyl transferase
THREONINE
aldolase
N5-N10THF
CO2, NH3 Glycine synthase
SYNTHESIS

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

39. Conjugation reactions

40. Detoxification – Benzoic acid Synthesis of Heme
(food preservative)

41. SYNTHESIS OF CREATINE
CREATININE

42. GLYCINE SYNTHETASE
SERINE HYDROXY METHYL TRANSFERASE
GLYCINE OXIDASE
TRANSAMINASE

44. PrimaryHyper oxaluria
- defect o glycine TA
❑ Increased urinry oxalate
❑ Deposition of oxalate in tissues
Disorders of GLYCINE
metabolism

45. Methionine- UTIIZATION, PRODUCTS

46. 1

47. 2
Condenses
with Serine
Enzyme
Cystathione
synthase
E-Methionine adenosyl transferase
E-Cystathionase
Homoserin
e
Note the role played by Vitamins
3
1
2
3
4
5

48. Leucine- Essential aa

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

52. Arginine- Essential aa

54. 1
2
3

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

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)