Lecture 5August 10, 2005

Lehninger Chapter 15 (4th ed.)

Lehninger Chapter 14 (4th ed.) complete sections 14.2 and 14.3skip section 14.4 for now

METABOLISM OF GLYCOGEN

Galactose Galactose 1-P

UDP-Glu

UDP-Gal

Glucose 1-P

Glucose 6-P

kinase

Uridyl transferase

epimerase

phosphoglucomutase

ATP ADP

Enzymes required for galactose metabolism

Figure 7-14b seen by electron microscopy

3 enzymes of glycogen breakdown(Glycogenolysis)

1) glycogen phosphorylase

2) glycogen debranching enzyme

3) phosphoglucomutase

Figure 7-11

Non-reducing end

Reducing end

Figure 7-10

Can reduce Cu2+

Cannot reduce Cu2+

Note this shows the β, not α configuration

Oxidized sugar

Figure 15-3

OH

Figure 15-4

Pyridoxal phosphatecofactor

1234

1234

Figure 15-3

Pyridoxal phosphatecofactor

3 enzymes of glycogen breakdown(Glycogenolysis)

1) glycogen phosphorylase

2) glycogen debranching enzyme [oligo (α1→6) to (α1→4) glucantransferase]

3) phosphoglucomutase

Figure 7-15b

1234

1234

1

1234234

Figure 15-4

Figure 15-4

Hydrolysis, NOTPhosphorolysis

3 enzymes of glycogen breakdown(Glycogenolysis)

1) glycogen phosphorylase

2) glycogen debranching enzyme

3) Phosphoglucomutase

Glu-1-P ↔ Glu-6-P

Figure 15-5

Glu 1-P Glu 6-Pphosphoglucomutase

LNC 15.13

GLYCOGEN METABOLISM

GLYCOGEN SYNTHESIS

LNC Chapter 15 (Section 1)

p. 565

UDP glucose is the activated precursor

Glu + ATP → Glu-6-P + ADP

Enzymes:

hexokinase I and

hexokinase II in muscle,

hexokinase IV (glucokinase) in liver

Glu-6-P ↔ Glu-1-P

Phosphoglucomutase

Glu-1-P + UTP → UDP-Glu + PPi

UDP-Glu

Glu-1-P

Figure 15-7

Figure 15-10

Start with glycogenin, a primer and enzyme.

Muscle form and Liver form (glycogenin-2)

+

UDP-glucose

Figure 15-11a

LNC (3rd ed) 20-14(not found in 4th edition)

Figure 15-8

Figure 15-9

Figure 15-11b

CONTROL OF GLYCOGEN SYNTHESIS

AND

BREAKDOWN

Fig 15-13

phosphorylasesynthase

Phosphofructokinase (PFK-1)

Fructose-1,6-bisphosphatase

GLYCOGEN

UDP-Glu Glu-1P

Glu-6P

Fru-6P

Fru-1,6 bis P

DHAP + GAP

Fig 15-14

Covalent modifications

Ligand-inducedconformational changes

Fig 15-24

Fig 15-26

ATP cAMP

adenylcyclase

phosphodiesterase

AMPADP

GTP cGMP

guanylcyclase

phosphodiesterase

LNC 12-15

hormone

Glycogen ==> Glu-1-P

Fig 15-25

Fig 15-27

Fig 15-29

2 ADP ATP AMP+

K = 0.44

Adenylate kinase