August 10, 2005

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Lecture 5

• August 10, 2005

Lehninger Chapter 14 (4th ed.) complete
sections 14.2 and 14.3 skip section 14.4 for
now
Lehninger Chapter 15 (4th ed.)
METABOLISM OF GLYCOGEN
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Enzymes required for galactose metabolism
kinase
Galactose Galactose 1-P
UDP-Glu
ATP ADP
Uridyl transferase
epimerase
UDP-Gal
Glucose 1-P
phosphoglucomutase
Glucose 6-P
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seen by electron microscopy
Figure 7-14b
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3 enzymes of glycogen breakdown(Glycogenolysis)

1. glycogen phosphorylase
2. glycogen debranching enzyme
3. phosphoglucomutase

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Non-reducing end
Reducing end
Figure 7-11
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Can reduce Cu2
Oxidized sugar
Cannot reduce Cu2
Figure 7-10
Note this shows the ß, not a configuration
8
OH
Figure 15-3
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Pyridoxal phosphate cofactor
1
2
3
4
1
2
3
4
Figure 15-4
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Pyridoxal phosphate cofactor
Figure 15-3
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3 enzymes of glycogen breakdown(Glycogenolysis)

1. glycogen phosphorylase
2. glycogen debranching enzyme oligo (a1?6) to
   (a1?4) glucantransferase
3. phosphoglucomutase

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Figure 7-15b
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1
2
3
4
1
2
3
4
1
1
2
3
4
2
3
4
Figure 15-4
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Hydrolysis, NOT Phosphorolysis
Figure 15-4
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3 enzymes of glycogen breakdown(Glycogenolysis)

• glycogen phosphorylase
• glycogen debranching enzyme
• Phosphoglucomutase
• Glu-1-P ? Glu-6-P

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Glu 1-P ? Glu 6-P phosphoglucomutase
Figure 15-5
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LNC 15.13
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GLYCOGEN METABOLISM
GLYCOGEN SYNTHESIS
LNC Chapter 15 (Section 1)
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UDP glucose is the activated precursor
p. 565
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Glu ATP ? Glu-6-P ADP

• Enzymes
• hexokinase I and
• hexokinase II in muscle,
• hexokinase IV (glucokinase) in liver

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Glu-6-P ? Glu-1-P

• Phosphoglucomutase

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Glu-1-P UTP ? UDP-Glu PPi
Glu-1-P
UDP-Glu
Figure 15-7
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Start with glycogenin, a primer and
enzyme. Muscle form and Liver form
(glycogenin-2)

Figure 15-10
UDP-glucose
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Figure 15-11a
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LNC (3rd ed) 20-14 (not found in 4th edition)
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Figure 15-8
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Figure 15-9
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Figure 15-11b
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CONTROL OF GLYCOGEN SYNTHESIS AND BREAKDOWN
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Fig 15-13
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GLYCOGEN UDP-Glu
Glu-1P Glu-6P Fru-6P Fru-1,6 bis
P DHAP GAP
phosphorylase
synthase
Fructose-1,6-bis phosphatase
Phosphofructokinase (PFK-1)
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Fig 15-14
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Covalent modifications
Ligand-induced conformational changes
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Fig 15-24
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Fig 15-26
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adenyl cyclase
ATP
cAMP
phosphodiesterase
ADP
AMP
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guanyl cyclase
GTP
cGMP
phosphodiesterase
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LNC 12-15
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Fig 15-25
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Fig 15-27
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Fig 15-29
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Adenylate kinase
2 ADP
ATP
AMP

K 0.44
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