Overall ATP Yields from 1 Glucose

Even though I eventually reached this point during the Wednesday, 24 March 1999 lecture, some of you probably didn't get it quite as smoothly as you (and I) would have liked. So, here is a nice summary. For Exam #3, you will have to know all the intermediates and at which steps these processes occur.

Aerobic

Glycolysis in liver/heart muscle: 38 ATP

Glycolysis Pyruvate to
Acetyl coA
Krebs Cycle/
Electron Transport
Chain
activation substrate-level
phosphorylation
NADH/H+
to ATP
2 x -1 2 x 2 2 x 3
-2 4 6
NADH/H+
to ATP
2 x 3
6
NADH/H+
to ATP
FADH2
to ATP
GTP
to ATP
2 x (3 x 3) 2 x 2 2 x 1
18 4 2

Glycolysis in skeletal muscle: 36 ATP

Glycolysis Pyruvate to
Acetyl coA
Krebs Cycle/
Electron Transport
Chain
activation substrate-level
phosphorylation
loss due to
glycerol-3-
phosphate shuttle
NADH/H+
to ATP
2 x -1 2 x 2 2 x -1 2 x 3
-2 4 -2 6
NADH/H+
to ATP
2 x 3
6
NADH/H+
to ATP
FADH2
to ATP
GTP
to ATP
2 x (3 x 3) 2 x 2 2 x 1
18 4 2

Anaerobic

Glycolysis in skeletal muscle, to lactate: 2 ATP

While 2 NADH/H+ are made in glycolysis proper, they are consumed in the conversion of pyruvate to lactate. Since there is insufficient O2 available, they cannot be converted to ATP in the mitochondria.

Glycolysis
activation substrate-level
phosphorylation
2 x -1 2 x 2
-2 4

Glycolysis in bacteria, to ethanol and CO2: 2 ATP

While 2 NADH/H+ are made in glycolysis proper, they are consumed in the conversion of pyruvate to ethanol. Since bacteria lack mitochondria and all the Krebs Cycle, electron transport, and oxidative phosphorylation enzymes, none of these ATP-generating pathways can be used.

Glycolysis
activation substrate-level
phosphorylation
2 x -1 2 x 2
-2 4

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