1. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-1The biosynthetic origins of purine ring atoms. Page 1069

2. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-2The metabolic pathway for the de novo biosynthesis of IMP. Page 1071

3. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-3The proposed mechanism of formylglycinamide ribotide (FGAM) synthetase. Page 1072

4. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-4IMP is converted to AMP or GMP in separate two-reaction pathways. Page 1074

5. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-5Control network for the purine biosynthesis pathway. Page 1075

6. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-6The biosynthetic origins of pyrimidine ring atoms. Page 1077

7. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-7Metabolic pathway for the de novo synthesis of UMP. Page 1077

8. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-8Reactions catalyzed by eukaryotic dihydroorotate dehydrogenase. Page 1078

9. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-9Proposed catalytic mechanism for OMP decarboxylase. Page 1079

10. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-10Synthesis of CTP from UTP. Page 1080

11. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-11Regulation of pyrimidine biosynthesis. The control networks are shown for (a) E. coli and (b) animals. Page 1080

12. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-12aClass I ribonucleotide reductase from E. coli. (a) A schematic diagram of its quaternary structure. Page 1082

13. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-12bClass I ribonucleotide reductase from E. coli. (b) The X-ray structure of R2 2. Page 1082

14. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-12cClass I ribonucleotide reductase from E. coli. (c) The binuclear Fe(III) complex of R2. Page 1082

15. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-12dClass I ribonucleotide reductase from E. coli. (d) The X-ray structure of the R1 dimer. Page 1082

16. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-13Enzymatic mechanism of ribonucleotide reductase. Page 1083

17. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-14aRibonucleotide reductase regulation. (a) A model for the allosteric regulation of Class I RNR via its oligomerization. Page 1085

18. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-14bRibonucleotide reductase regulation. (b) The X-ray structure of the R1 hexamer, which has D 3 symmetry, in complex with ADPNP as viewed along its 3-fold axis. Page 1085

19. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-14cRibonucleotide reductase regulation. (c) The R1·ADPNP hexamer as viewed along the vertical 2-fold axis in Part b. Page 1085

20. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-15X-Ray structure of human thioredoxin in its reduced (sulfhydryl) state. Page 1086

21. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-16Electron-transfer pathway for nucleoside diphosphate (NDP) reduction. Page 1087

22. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-17aX-Ray structures of E. coli thioredoxin reductase (TrxR). (a) The C138S mutant TrxR in complex with NADP +. Page 1087

23. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-17bThe C135S mutant thioredoxin reductase (TrxR) in complex with AADP +, disulfide-linked to the C35S mutant of Trx. Page 1087

24. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-18aX-Ray structure of human dUTPase. (a) The molecular surface at the substrate binding site showing how the enzyme differentiates uracil from thymine. Page 1089

25. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-18bX-Ray structure of human dUTPase. (b) The substrate binding site indicating how the enzyme differentiates uracil from cytosine and 2-deoxyribose from ribose. Page 1089

26. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-19Catalytic mechanism of thymidylate synthase. Page 1090

27. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-20The X-ray structure of the E. coli thymidylate synthase–FdUMP–THF ternary complex. Page 1091

28. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-21Regeneration of N5,N10- methylenetetrahydrofolate. Page 1091

29. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-22Ribbon diagram of human dihydrofolate reductase in complex with folate. Page 1091

30. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-23Major pathways of purine catabolism in animals. Page 1093

31. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-24aStructure and mechanism of adenosine deaminase. (a) A ribbon diagram of murine adenosine deaminase in complex with its transition state analog HDPR. Page 1094

32. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-24bStructure and mechanism of adenosine deaminase. (b) The proposed catalytic mechanism of adenosine deaminase. Page 1094

33. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-25The purine nucleotide cycle. Page 1095

34. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-26aX-Ray structure of xanthine oxidase from cow’s milk in complex with salicylic acid. (a) Ribbon diagram of its 1332-residue subunit. Page 1095

35. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-26bX-Ray structure of xanthine oxidase from cow’s milk in complex with salicylic acid. (b) The enzyme’s redox cofactors and salicylic acid (Sal). Page 1095

36. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-27Mechanism of xanthine oxidase. Page 1096

37. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-28Degradation of uric acid to ammonia. Page 1097

38. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-29The Gout, a cartoon by James Gilroy (1799). Page 1097

39. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-30Major pathways of pyrimidine catabolism in animals. Page 1098

40. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-31Pathways for the biosynthesis of NAD + and NADP +. Page 1099

41. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-32Biosynthesis of FMN and FAD from the vitamin precursor riboflavin. Page 1100

42. Voet Biochemistry 3e © 2004 John Wiley & Sons, Inc. Figure 28-33Biosynthesis of coenzyme A from pantothenate, its vitamin precursor. Page 1101