Lecture 5 August 10, 2005 Lehninger Chapter 15 (4 th ed.) Lehninger Chapter 14 (4 th ed.) complete...

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