Figure 26-1 Forms of pyridoxal-5’-phosphate. (a) Pyridoxine (vitamin B6) and (b) Pyridoxal-5’-phosphate (PLP) (c) Pyridoxamine-5’-phosphate (PMP) and (d) The Schiff base that forms between PLP and an enzyme -amino group.. Page 986
Figure 26-48The two-stage reduction of folate to THF. Page 1028
Table 26-1Oxidation Levels of C 1 Groups Carried by THF. Page 1028
Page 1029 Figure 26-49 Interconversion of the C 1 units carried by THF.
Figure 26-50The biosynthetic fates of the C 1 units in the THF pool. Page 1029
Page 1031 Figure 26-51 The sequence of reactions catalyzed by glutamate synthase.
Table 26-2Essential and Nonessential Amino Acids in Humans. Page 1030 We can’t make these! We can make these!
Page 1033 Figure 26-54 The syntheses of alanine, aspartate, glutamate, asparagine, and glutamine.
Figure 26-55aX-Ray structure of S. typhimurium glutamine synthetase. (a) View down the 6-fold axis of symmetry showing only the six subunits of the upper ring in alternating blue and green. Page 1034
Page 1035 Figure 26-56 The regulation of bacterial glutamine synthetase.
Figure 26-57The biosynthesis of the “glutamate family” of amino acids: arginine, ornithine, and proline. Page 1036
Figure 26-58The conversion of 3- phosphoglycerate to serine. Page 1037
Figure 26-66Photograph showing the root nodules of the legume bird’s foot trefoil. Page 1046
Figure 26-67X-Ray structure of the A. vinelandii nitrogenase in complex with ADP · AlF 4 . Page 1046
Figure 26-69The flow of electrons in the nitrogenase- catalyzed reduction of N 2. Page 1048
Figure 26-59aCysteine biosynthesis. (a) The synthesis of cysteine from serine in plants and microorganisms. Page 1038
Figure 26-59bCysteine biosynthesis. (b) The 8-electron reduction of sulfate to sulfide in E. coli. Page 1038
Figure 26-60The biosynthesis of the “aspartate family” of amino acids: lysine, methionine, and threonine. Page 1039
Table 26-3Differential Control of Aspartokinase Isoenzymes in E. Coli. Page 1041
Figure 26-61The biosynthesis of the “pyruvate family” of amino acids: isoleucine, leucine, and valine. Page 1040
Figure 26-62The biosynthesis of chorismate, the aromatic amino acid precursor. Page 1042
Figure 26-63The biosynthesis of phenylalanine, tryptophan, and tyrosine from chorismate. Page 1043
Figure 26-64A ribbon diagram of the bifunctional enzyme tryptophan synthase from S. typhimurium Page 1044
Figure 26-65The biosynthesis of histidine. Page 1045