Figure 17-24 Reaction mechanism of lactate dehydrogenase. Via accompan
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Proton donation from HisFacilitated by Arg
Figure 17-25 The two reactions of alcoholic
fermentation.
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Figure 17-26 Thiamine pyrophosphate.
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Voet Biochemistry 3e© 2004 John Wiley & Sons, Inc.
Figure 17-27 Reaction mechanism of pyruvate decarboxylase.
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Nucleophillic attack
Protonation of carbanion
elimination
Figure 17-29 The formation of the active ylid form of TPP in the
pyruvate decarboxylase
reaction.
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Figure 17-30 The reaction mechanism of alcohol dehydrogenase involves direct hydride transfer of the pro-R hydrogen of NADH to the re face of acetaldehyde.
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Table 17-2 Some Effectors of the Nonequilibrium Enzymes of Glycolysis.
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Please note that these are the 3 NON-reversible reactions of glycolysis. All the others are freely reversible.
Figure 17-32a X-Ray structure of PFK. (a) A ribbon diagram showing two subunits of the
tetrameric E. coli protein.
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Mg+2
ATP
F6P
Figure 17-33 PFK activity versus F6P concentration.
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Figure 17-35 Metabolism of fructose.
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Figure 17-36 Metabolism of galactose.
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Figure 17-37 Metabolism of mannose.
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Figure 18-1a Structure of glycogen. (a) Molecular formula. (b) Schematic diagram illustrating its branched structure.
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Figure 18-2a X-Ray structure of rabbit muscle glycogen phosphorylase. (a) Ribbon
diagram of a phosphorylase b subunit.
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Figure 18-2bX-Ray
structure of rabbit muscle
glycogen phosphorylase.
(b) A ribbon diagram of the
glycogen phosphorylase
a dimer.
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Figure 18-2c X-Ray structure of rabbit muscle glycogen phosphorylase. (c) An interpretive “low-
resolution” drawing of Part b showing the enzyme’s various ligand-binding sites.
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Figure 18-3The reaction mechanism of glycogen phosphorylase.
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Figure 18-4 The mechanism of action of
phosphoglucomutase.
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Figure 18-5 Reactions catalyzed by debranching enzyme.
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Figure 18-6 Reaction catalyzed by UDP–glucose pyrophos-phorylase.
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Figure 18-7 Reaction catalyzed by glycogen
synthase.
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Figure 18-8 The branching of glycogen.
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Figure 18-9 The control of glycogen phosphorylase activity.
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Figure 18-10aConformational changes in glycogen phosphorylase. (a) Ribbon diagram of one subunit (T-state) in absence of allosteric effectors.
a.
(b) Ribbon diagram of one subunit (R-state) with bound AMP. b.
Figure 18-10b
Conformational changes in
glycogen phosphorylase
. (b) The portion of the
glycogen phosphorylase a dimer in the vicinity of the
dimer interface.
Figure 18-11a A monocyclic enzyme cascade. (a) General scheme, where F and R are, respectively, the
modifying and demodifying enzymes.
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Figure 18-11b A monocyclic enzyme cascade.(b) Chemical equations for the interconversion of the
target enzyme’s unmodified and modified forms Eb and Ea.
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Figure 18-12 A bicyclic enzyme cascade.
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Figure 18-13 Schematic diagram of the major enzymatic modification/demodification systems involved
in the control of glycogen metabolism in muscle.
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Figure 18-14 X-ray structure of the catalytic (C) subunit of mouse protein kinase A (PKA).
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Figure 18-15 X-ray structure of the regulatory (R) subunit of
bovine protein kinase A (PKA).
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Figure 18-16 X-Ray structure of rat testis calmodulin.
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Figure 18-17 EF hand. P
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Figure 18-18a. NMR structure of (Ca2+)4–CaM from Drosophila melanogaster in complex with its 26-residue target polypeptide
from rabbit skeletal muscle myosin light chain kinase (MLCK). (a) A view of the complex in which the N-terminus of the target
polypeptide is on the right.
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Figure 18-18b. NMR structure of (Ca2+)4–CaM from Drosophila melanogaster in complex with its 26-residue target polypeptide
from rabbit skeletal muscle myosin light chain kinase (MLCK). (b) The perpendicular view as seen from the right side of Part a.
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Figure 18-19Schematic diagram of the Ca2+–CaM-
dependent activation of protein kinases.
Figure 18-21 The antagonistic effects of insulin and epinephrine on glycogen metabolism in muscle.
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Figure 18-22 The enzymatic activities of phosphorylase a and glycogen synthase in
mouse liver in response to an infusion of glucose.
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Figure 18-23 Comparison of the relative enzymatic activities of hexokinase and glucokinase over the
physiological blood glucose range.
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Figure 18-24 Formation and degradation of -D-fructose-2,6-bisphosphate as catalyzed by PFK-2 and
FBPase-2.
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Figure 18-25 X-ray structure of the H256A mutant of rat testis
PFK-2/FBPase-2.
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Figure 18-26aThe liver’s response to stress. (a) Stimulation of α-adrenoreceptors by epinephrine activates phospholipase C to hydrolyze PIP2 to IP3 and DAG.
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Figure 18-26bThe liver’s response to stress. (b) The participation of two second messenger systems.
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Figure 18-27 The ADP concentration in human forearm muscles during rest and following exertion in normal individuals and those with McArdle’s disease.
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(Muscle Phosphorylase Deficiency)
Table 18-1Hereditary Glycogen Storage Diseases.
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“Alfonse, Biochemistry makes my head hurt!!”\