Cellular Respiration Harvesting Chemical Energy

Page
6

i

ATP

NADH

Slide 43

The citric acid cycle has eight steps, each catalyzed by a specific enzyme

The acetyl group of acetyl CoA joins the cycle by combining with oxaloacetate, forming citrate

The next seven steps decompose the citrate back to oxaloacetate, making the process a cycle

The NADH and FADH2 produced by the cycle relay electrons extracted from food to the electron transport chain

Slide 44

Fig. 9-12-1

Acetyl CoA

Oxaloacetate

CoA—SH

1

Citrate

Citric

acid

cycle

Slide 45

Fig. 9-12-2

Acetyl CoA

Oxaloacetate

Citrate

CoA—SH

Citric

acid

cycle

1

2

H2O

Isocitrate

Slide 46

Fig. 9-12-3

Acetyl CoA

CoA—SH

Oxaloacetate

Citrate

H2O

Citric

acid

cycle

Isocitrate

1

2

3

NAD+

NADH

+ H+

-Keto-

glutarate

CO2

Slide 47

Fig. 9-12-4

Acetyl CoA

CoA—SH

Oxaloacetate

Citrate

H2O

Isocitrate

NAD+

NADH

+ H+

Citric

acid

cycle

-Keto-

glutarate

CoA—SH

1

2

3

4

NAD+

NADH

+ H+

Succinyl

CoA

CO2

CO2

Slide 48

Fig. 9-12-5

Acetyl CoA

CoA—SH

Oxaloacetate

Citrate

H2O

Isocitrate

NAD+

NADH

+ H+

CO2

Citric

acid

cycle

CoA—SH

-Keto-

glutarate

CO2

NAD+

NADH

+ H+

Succinyl

CoA

1

2

3

4

5

CoA—SH

GTP

GDP

ADP

P

i

Succinate

ATP

Slide 49

Fig. 9-12-6

Acetyl CoA

CoA—SH

Oxaloacetate

H2O

Citrate

Isocitrate

NAD+

NADH

+ H+

CO2

Citric

acid

cycle

CoA—SH

-Keto-

glutarate

CO2

NAD+

NADH

+ H+

CoA—SH

P

Succinyl

CoA

i

GTP

GDP

ADP

ATP

Succinate

FAD

FADH2

Fumarate

1

2

3

4

5

6

Slide 50

Fig. 9-12-7

Acetyl CoA

CoA—SH

Oxaloacetate

Citrate

H2O

Isocitrate

NAD+

NADH

+ H+

CO2

-Keto-

glutarate

CoA—SH

NAD+

NADH

Succinyl

CoA

CoA—SH

P

P

GDP

GTP

ADP

ATP

Succinate