Cellular Respiration Harvesting Chemical Energy

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4

Glycolysis occurs in the cytoplasm and has two major phases:

Energy investment phase

Energy payoff phase

Slide 29

Fig. 9-8

Energy investment phase

Glucose

2 ADP + 2

P

2 ATP

used

formed

4 ATP

Energy payoff phase

4 ADP + 4

P

2 NAD+ + 4 e– + 4 H+

2 NADH

+ 2 H+

2 Pyruvate + 2 H2O

2 Pyruvate + 2 H2O

Glucose

Net

4 ATP formed – 2 ATP used

2 ATP

2 NAD+ + 4 e– + 4 H+

2 NADH + 2 H+

Slide 30

Fig. 9-9-1

ATP

ADP

Hexokinase

1

ATP

ADP

Hexokinase

1

Glucose

Glucose-6-phosphate

Glucose

Glucose-6-phosphate

Slide 31

Fig. 9-9-2

Hexokinase

ATP

ADP

1

Phosphoglucoisomerase

2

Phosphogluco-

isomerase

2

Glucose

Glucose-6-phosphate

Fructose-6-phosphate

Glucose-6-phosphate

Fructose-6-phosphate

Slide 32

1

Fig. 9-9-3

Hexokinase

ATP

ADP

Phosphoglucoisomerase

Phosphofructokinase

ATP

ADP

2

3

ATP

ADP

Phosphofructo-

kinase

Fructose-

1, 6-bisphosphate

Glucose

Glucose-6-phosphate

Fructose-6-phosphate

Fructose-

1, 6-bisphosphate

1

2

3

Fructose-6-phosphate

3

Slide 33

Fig. 9-9-4

Glucose

ATP

ADP

Hexokinase

Glucose-6-phosphate

Phosphoglucoisomerase

Fructose-6-phosphate

ATP

ADP

Phosphofructokinase

Fructose-

1, 6-bisphosphate

Aldolase

Isomerase

Dihydroxyacetone

phosphate

Glyceraldehyde-

3-phosphate

1

2

3

4

5

Aldolase

Isomerase

Fructose-

1, 6-bisphosphate

Dihydroxyacetone

phosphate

Glyceraldehyde-

3-phosphate

4

5

Slide 34

Fig. 9-9-5

2 NAD+

NADH

2

+ 2 H+

2

2

P

i

Triose phosphate

dehydrogenase

1, 3-Bisphosphoglycerate

6

2 NAD+

Glyceraldehyde-

3-phosphate

Triose phosphate

dehydrogenase

NADH

2

+ 2 H+

2

P

i

1, 3-Bisphosphoglycerate

6

2

2

Slide 35

Fig. 9-9-6

2 NAD+

NADH

2

Triose phosphate

dehydrogenase

+ 2 H+

2

P

i

2

2 ADP

1, 3-Bisphosphoglycerate

Phosphoglycerokinase

2 ATP

2

3-Phosphoglycerate

6

7

2

2 ADP

2 ATP