1.4 Biosynthesis of purines and pyrimidines

What is this

Nucleobase - precursors of DNA and RNA, functions as storage (DNA) or in protein synthesis (tRNA, rRNA)

What is this

Nucleoside - DNA/RNA base on ribose and functions in carrying genetic material

What is this

Nucleotide - carriers of chemical energy and functions in energy metabolism

Label this

1. Glycine - purines

2. Formate

3. Amide N of Glutamine

4. Aspartate - pyrimidines

5. CO2

Label this

1. IMP ( Inosinate )

2. Aspartate

3. GTP

4. GDP + Pi

5. Adenylosuccinate synthetase

6. Adenylosuccinate

7. Fumarate

8. Adenylosuccinate lyase

9. Adenylate ( AMP)

10. IMP Dehydrogenase

11. H20

12. NAD+

13. NADH + H+

14. Xanthylate ( XMP)

15. Glutamine

16. Glutamate

17. ATP

18. AMP + Pi

19. XMP-glutamine amidotransferase

20. Guanylate ( GMP)

Increase levels of AMP and GMP inhibit what

• Glutamine- PRPP aminotransferase

• IMP dehydrogenase

• Adenylosuccinate synthetase

Label

1. dUMP

2. dTMP

3. Thymidylate synthase

4. N5,N10 - methylenetetrahydrofolate

5. 7,8 - Dihydrofolate

6. Dihydrofolate reductase

7. NADPH + H+

8. NADP+

9. Tetrahydrofolate

10. Serine

11. Glycine

12. Serine hydroxymethyltransferase

De novo pathways

Synthesis of nucleotides begins with their metabolic precursors

Salvage pathways

Recycle free bases and nucleosides released from nucleic acid breakdown