Glycine is a non-essential amino acid that plays important roles in many metabolic pathways and biomolecule synthesis. It can be synthesized from serine, threonine, glyoxalate, and other biomolecules. Glycine is degraded to produce ammonia and carbon dioxide. It is involved in the synthesis of molecules like glutathione, heme, creatine, purines, and bile acids. Glycine metabolism links many pathways together and is essential for processes like collagen synthesis, detoxification, and amino acid synthesis. Metabolic disorders of glycine can result in conditions like glycinuria and primary hyperoxaluria which can lead to kidney stone formation.

1. Glycine metabolism
Dr Rohini C Sane

2. Glycine metabolism
1) Non essential amino acids
2) Glucogenic amino acids
 FUNCTIONS OF GLYCINE
AMMONIA GLUCOSE
BILE SALTS GLUTATHIONE
CREATINE HEME
DETOXIFICATION OXLATES
SERINE PROTEIN PURINE
GLYCINE
FUCTIONS OF Glycine : ABCDGGHOPPS

3. Synthesis of
Glycine
From
different
biomolecules

4. Glycine metabolism
1.Synthesis of Glycine from Serine

5. Synthesis of
Glycine from -
Serine
Reversible
reaction

6. Synthesis of Glycine from Threonine
Synthesis of
Glycine from
Threonine

7. Synthesis of
Glycine
from
Glyoxalate

8. Degradation of Glycine

9. Degradation of Glycine to Ammonia &CO2
Role of THF in Glycine Metabolism and Ammonia synthesis

10. Degradation of Glycine to Ammonia &CO2
Role of THF in Glycine Metabolism

11. Role of Glycine in synthesis of Cysteine

12. Role of Glycine biosynthesis of molecules

13. Glycine links
many
Metabolic
pathways &
biomolecules

14. Functions of Glycine: Collagen synthesis
1. Collagen –rich in Glycine -30%

15. Functions of Glycine :Formation of purine ring
2.Formation of purine ring : N7

16. Functions of Glycine -3.Synthesis of Glutathione

17. Functions of Glycine in Detoxification by conjugation reaction
4.Detoxification by conjugation reaction
• Bile acids cholic acid /cheno cholic acid
• Cholic acid + Glycine Glycocholic acid
• Chenodeoxy cholic acid+ Glycine Glyco- cheno deoxy cholic acid
• Benzoic acid +Glycine  Hippuric acid (excreted by kidney )

18. Functions of Glycine in synthesis of Heme
5.synthesis of Heme
Succinyl CoA + Glycine δ Amino levulinate (ALA )
HEME
ALA SYNTHTASE

19. Synthesis of Heme from Glycine

20. Functions of Glycine: Biosynthesis of Creatine
Source of Energy
In muscles
Excretion in urine

21. Creatine & creatinine : clinical significance
Creatine Creatinine
Serum 0.2 -0.6 mg/ dl 0.6 -1.0 mg/ dl
Urine 0 – 50 mg/day 1 -2 gm /day
Creatinine estimation
–KFT ( CREATININE –ENDOGENOUS ,NOT ABSORBED NOR SECRETED SECRETION,DAILY EXCRETION )
 Creatinine coefficient - mg / kg body weight / day
Man - 24-26 mg / kg body weight / day
Woman - 20- 22 mg / kg body weight / day
Creatnuria : muscular dystrophy /Diabetes Mellitus / Hyperthyroidism/ starvation

22. Arginine ,Glycine
& Methionine
(SAM)
involved in
synthesis of
Creatine

23. Metabolic disorders of Glycine
Glycinuria
• Serum Glycine concentration is normal/increased in excretion of Glycine
in urine ( defective renal reabsorption of Glycine )
• Increased formation of urinary oxlate calculi (stones )
Primary hyperoxaluria
Increased formation of urinary oxlate calculi
↓
oxalosis ( deposition in various tissue )
Generally defective Glycine transaminase
+ impairment in Glyoxalate oxidation to Formate
Vitamin B12 deficiency :Increased formation of urinary oxlate calculi
(stones )  corrected by Vitamin B12 supplementation

24. Glycinuria :
Metabolic disorders
of Glycine

25. Role of Glycine in oxalate formation

26. Primary Oxaluria type I
leads to renal /kidney
stone formation
& is responsible for
mental retardation

27. Kidney stones ( Calcium oxalate )

28. Hepatocytes of liver are
involved in
Oxalate synthesis & renal
cells are Involved in oxalate
excretion

29. Summary
Of Metabolic
pathways of
Glycine