Cellular Respiration Harvesting Chemical Energy

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Proteins

Carbohydrates

Amino

acids

Sugars

Fats

Glycerol

Fatty

acids

Glycolysis

Glucose

Glyceraldehyde-3-

Pyruvate

P

NH3

Acetyl CoA

Citric

acid

cycle

Oxidative

phosphorylation

Slide 81

Biosynthesis (Anabolic Pathways)

The body uses small molecules to build other substances

These small molecules may come directly from food, from glycolysis, or from the citric acid cycle

Slide 82

Regulation of Cellular Respiration via Feedback Mechanisms

Feedback inhibition is the most common mechanism for control

If ATP concentration begins to drop, respiration speeds up; when there is plenty of ATP, respiration slows down

Control of catabolism is based mainly on regulating the activity of enzymes at strategic points in the catabolic pathway

Slide 83

Fig. 9-21

Glucose

Glycolysis

Fructose-6-phosphate

Phosphofructokinase

Fructose-1,6-bisphosphate

Inhibits

AMP

Stimulates

Inhibits

Pyruvate

Citrate

Acetyl CoA

Citric

acid

cycle

Oxidative

phosphorylation

ATP

+

–

–

Slide 84

Fig. 9-UN5

Inputs

Glycolysis

Outputs

+

2

2

ATP

NADH

2

Glucose

Pyruvate

Slide 85

Fig. 9-UN6

Inputs

Outputs

Acetyl CoA

2

2

2

2

6

ATP

NADH

FADH2

Oxaloacetate

Citric acid

cycle

S—CoA

CH3

C O

O C COO

CH2

COO

Slide 86

Fig. 9-UN7

INTER-

MEMBRANE

SPACE

H+

ATP

synthase

ATP

ADP +

P

i

H+

MITO-

CHONDRIAL

MATRIX

Slide 87

Fig. 9-UN8

pH difference

across membrane

Time

Slide 88

Fig. 9-UN9

Slide 89

You should now be able to:

Explain in general terms how redox reactions are involved in energy exchanges

Name the three stages of cellular respiration; for each, state the region of the eukaryotic cell where it occurs and the products that result

In general terms, explain the role of the electron transport chain in cellular respiration

Slide 90