Chart of Important Metabolic Products

All products are expressed in terms of number of molecules per glucose  

Table 1.  For aerobic metabolism

 

ATP used

ATP produced

NADH produced

FADH2 produced

CO2 produced

Glycolysis

 

Hexokinase

1

 

 

 

 

Phosphofructokinase

1

 

 

 

 

Triose phosphate dehydrogenase

 

 

2

 

 

Phosphoglycerokinase

 

2

 

 

 

Pyruvate kinase

 

2

 

 

 

Glycolysis totals

2

4

2

0

0

Pyruvate to Acetyl CoA (pyruvate dehydrogenase)

 

 

2

 

2

Krebs cycle

 

Isocitrate dehydrogenase

 

 

2

 

2

a-ketoglutarate dehydrogenase

 

 

2

 

2

Succinyl thiokinase + nucleoside diphosphate kinase

 

2

 

 

 

Succinate dehydrogenase

 

 

 

2

 

Malate dehydrogenase

 

 

2

 

 

Krebs cycle totals

0

2

6

2

4

GRAND TOTALS
 of Aerobic Metabolism

2

6

2 from glycolysis, 8 after

2

6

q       In brain and skeletal muscle cells the NADH from glycolysis produce 2 ATP each at the electron transport chain.

q       In liver, kidney, and heart muscle cells the NADH from glycolysis produce 3 ATP each at the electron transport chain.

q       In the pyruvate dehydrogenase step, the NADH produce 3 ATP each at the electron transport chain.

q       In the Krebs cycle, the NADH produce 3 ATP each at the electron transport chain.

q       In the Krebs cycle, the FADH2 produce 2 ATP each at the electron transport chain.

o        ATP produced by substrate level phosphorylation per glucose molecule = 6 (However, 2 are used to start glycolysis.  Therefore, there is a net gain of 4 ATP produced by substrate level phosphorylation.)

o        ATP produced by oxidative phosphorylation per glucose molecule

§         In brain and skeletal muscle = 4 + 24 + 4 = 32

§         In liver, kidney, and heart muscle = 6 + 24 + 4 = 34

o        In aerobic conditions, in brain and skeletal muscle the number of ATP produced per glucose = 36

o       In aerobic conditions, in liver, kidney, and heart muscle the number of ATP produced per glucose = 38

Table 2. For anaerobic metabolism

 

ATP used

ATP produced

NADH produced

FADH2 produced

CO2 produced

Glycolysis

 

Hexokinase

1

 

 

 

 

Phosphofructokinase

1

 

 

 

 

Triose phosphate

Dehydrogenase

 

 

2

 

 

Phosphoglycerokinase

 

2

 

 

 

Pyruvate kinase

 

2

 

 

 

Glycolysis totals

2

4

2

0

0

In muscle cells

Pyruvate to lactate
(lactate dehydrogenase)

 

 

2 NAD+ regenerated

 

2

In yeast cells

Pyruvate to acetaldehyde (pyruvate decarboxylase)

Acetaldehyde to ethyl alcohol (alcohol dehydrogenase)

 

 

 

 

 

 

 

2 NAD+ regenerated

 

2

 

GRAND TOTALS of Anaerobic Metabolism

2

4

2 NADH produced from glycolysis  

2 NAD+ regenerated in muscle and yeast cells

0

2

q       In brain cells the NADH from glycolysis cannot be regenerated.  These cells are dependent on aerobic metabolism for NAD+ regeneration.

q       In skeletal muscle cells the NADH from glycolysis is regenerated as NAD+ in the reaction of pyruvate à lactate.

q       In yeast cells the NADH from glycolysis is regenerated as NAD+ in the two reactions that convert pyruvate to ethyl alcohol.

o        ATP produced by substrate level phosphorylation per glucose molecule = 4. However, 2 are used to start glycolysis.  Therefore, there is a net gain of 2 ATP, which is enough to start glycolysis again, if there is a mechanism to regenerate NAD+.

o       In anaerobic conditions, in brain cells, no ATP is formed because NAD+ cannot be regenerated.

o       In anaerobic conditions, there is no oxidative phosphorylation.