2. Role of Amino Acids Protein monomeric units Energy source Precursors of other biological molecules Protein monomeric units Energy source Precursors of other biological molecules

3. 3 In Mammals Plants and bacteria can produce all of them

4. Amino acids are precursors 4

5. 5

8. 8 Biosynthesis of Amino Acids The nitrogen cycle

9. 9 Biosynthesis of Amino Acids Nitrogen Fixation -> Microorganism

10. 10 Major Ammonium ion carrier Ammonium Ion Is Assimilated into Amino Acids Through Glutamate and Glutamine

11. 11 Biosynthesis of Amino Acids

12. 12 Biosynthesis of Amino Acids in Bacteria and Plants Essential ones are in bold letters

13. 13 Biosynthesis of Amino Acids in Bacteria and Plants

14. 14 Biosynthesis of Amino Acids: Transaminations Amino Acid 1 +  -Keto Acid 2 Amino Acid 2 +  -Keto Acid 1 Glutamate +  - Ketoglutarate + Pyridoxal phosphate (PLP)- Dependent Aminotransferase

15. Products of Amino Acid Breakdown Glucogenic – Pyruvate –  -Ketoglutarate – Succinyl-CoA – Fumarate – Oxaloacetate Ketogenic – Acetyl-CoA – Acetoacetate

16. Animals cannot carryout net synthesis of precursors of gluconeogenesis from acetyl-CoA or acetoacetate

17. 17 Amino Acid Metabolism

18. 18 Fate of the C-Skeleton of Amino Acids

19. 19 Fate of the C-Skeleton of Amino Acids

20. 20 Fate of the C-Skeleton of Amino Acids Aromatic amino acids need oxygenases + O 2

21. 21 Fate of Nitrogen in Different Organism

23. Overall Urea Cycle (Liver)

24. Carbamyl Phosphate Synthetase (CPS) CPSI (Mitochondria) – Uses NH 3 – Urea Cycle CPSII (Cytosol) – Uses Glutamine – Pyrimidine Biosynthesis

25. Carbamyl Phosphate Synthetase (CPS) Mechanism

26. Activation of HCO 3 – by ATP

27. Displacement of Phosphate by NH 3

28. Phosphorylation of Carbamate by ATP

29. Ornithine Transcarbamylase (OTC) (Mitochondrion)

30. Citrulline Carrier (Ornithine Antiport)

31. Argininosuccinate Synthetase (Cytosol)

32. Mechanism

33. 33 Ammonium Ion is Converted into Urea Urea cycle

34. 34 The Urea Cycle is Linked to the Citric Acid Cycle NH 4 +