Table 25-2 Sphingolipid Storage Diseases.

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Figure 25-89 The breakdown of sphingolipids by lysosomal enzymes.

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Figure 25-90 Model for GM2-activator protein–stimulated hydrolysis of

ganglioside GM2 by hexosaminidase A.

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Figure 25-91 Cytoplasmic membranous body in a neuron

affected by Tay–Sachs disease.

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Chapter 27, Nitrogen Metabolism

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..

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Figure 26-2 The mechanism of PLP-dependent enzyme-catalyzed transamination.

Figure 26-3 The glucose–alanine cycle.

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Figure 26-4 The oxidative deamination of glutamate by glutamate DH.

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Figure 26-7The urea cycle.

Figure 26-8 The mechanism of action of CPS I.

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Figure 26-9 X-Ray structure of E. coli carbamoyl phosphate synthetase (CPS).

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Figure 26-10 The mechanism of action of argininosuccinate

synthetase.

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Figure 26-11

Degradation of amino acids

to one of seven

common metabolic

intermediates.

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Figure 26-12 The

pathways converting

alanine, cysteine, glycine,

serine, and threonine to

pyruvate.

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Figure 26-26The pathway of phenylalanine degradation.

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Figure 26-26The pathway of phenylalanine degradation.

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Figure 26-26The pathway of phenylalanine degradation.

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Figure 26-27 The

pteridine ring, the

nucleus of biopterin

and folate.

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10Figure 26-28 Formation, utilization, and regeneration of 5,6,7,8-tetrahydrobiopterin (BH4) in the phenylalanine hydroxylase reaction.

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Figure 26-30 Proposed mechanism of the NIH shift in the phenylalanine hydroxylase reaction.

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Figure 26-31 The NIH shift in the p-hydroxy-phenyl-pyruvate dioxygenase reaction.

Homogentisate

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Figure 26-32Structure of heme.

Figure 26-47 Tetrahydrofolate (THF).

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Figure 26-48 The two-stage reduction of folate to THF.

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Table 26-1 Oxidation Levels of C1 Groups Carried by THF.

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Figure 26-49Interconversion of the C1 units carried by THF.

Figure 26-50 The biosynthetic fates of the C1 units in the THF

pool.

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Figure 26-51The sequence of reactions catalyzed by glutamate synthase.

Table 26-2 Essential and Nonessential Amino Acids in Humans.

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We can’t make these! We can

makethese!

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Figure 26-54The syntheses of alanine, aspartate, glutamate, asparagine, and glutamine.

Figure 26-55a X-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.

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35Figure 26-56The regulation of bacterial glutamine synthetase.

Figure 26-57The biosynthesis of the “glutamate family” of amino acids: arginine, ornithine, and

proline.

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Figure 26-58The conversion of

3-phosphoglycerate

to serine.

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Figure 26-66 Photograph showing the root nodules of the

legume bird’s foot trefoil.

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Figure 26-67 X-Ray structure of the A. vinelandii nitrogenase in

complex with ADP · AlF4 .

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Figure 26-69 The flow of electrons in the nitrogenase-catalyzed reduction of N2.

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Figure 26-59a Cysteine biosynthesis. (a) The synthesis of cysteine from serine in plants and

microorganisms.

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Figure 26-59b Cysteine biosynthesis. (b) The 8-electron reduction of sulfate to sulfide in

E. coli.

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Figure 26-60 The biosynthesis of the “aspartate family” of

amino acids: lysine, methionine, and threonine.

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Table 26-3 Differential Control of Aspartokinase Isoenzymes in

E. Coli.

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Figure 26-61 The biosynthesis of the “pyruvate family” of

amino acids: isoleucine, leucine, and valine.

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Figure 26-62 The biosynthesis of chorismate, the aromatic

amino acid precursor.

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Figure 26-63 The biosynthesis of phenylalanine, tryptophan, and

tyrosine from chorismate.

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Figure 26-64 A ribbon diagram of the bifunctional enzyme tryptophan synthase

from S. typhimurium

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Figure 26-65 The biosynthesis of histidine.

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