ATP Produced in oxidation of glucose (30, 32, 36?)?

[onedirection]

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Okay so is it 36 ATP produced per glucose?

Well the question was

If E. coli si incubated under aerobic conditions, how many molecules of ATP would be produced upon the complete oxidation fo one molecule of glucose

Answer Key: 32 ATP Per glucose
Also solutions manual says In Eukaryotes, 30 ATP per glucose

Can someone explain?

Why the 32 and why the 30?

 

[FeinMS]

There was a post recently which value you should go by. I can't recall the value. But difference comes from efficiency of transporting electrons from NADH produce from glycolysis. Since glycolysis occurs in the cytosol and electrons on NADH must be transported to mitochondria, there are different mechanisms for the transport with different efficiency.
I know this is getting too specific, but for example, one mechanism transports 2e from cytosolic NADH to mitochondrial NADH. This mechanism is efficient but slow. However, another mechanism transports 2e from cytosolic NADH to mitochondrial FADH2. This mechanism is less efficient but faster because obviously FADH2 produces less ATP/mole than NADH.

 

[Vurday]

Glycolysis: 2 ATP, 2 NADH
PDC: 2 NADH
Kreb's Cycle: 2 GTP, 2 FADH2, 6 NADH

NADH from Cytosol: 1.5 ATP/NADH (enters Electron Transport Chain at the same step as FADH2, one step later than NADH. This leads to less ATP per molecule)
NADH in Mitochondria: 2.5 ATP/NADH
FADH2 in Mitochondria: 1.5 ATP/FADH2

So we have:
2 ATP
2 GTP --> 2 ATP
2 NADH (Cytosol) * 1.5 = 3 ATP
8 NADH (Mitochondria) * 2.5 = 20 ATP
2 FADH2 (Mitochondria) * 1.5 = 3 ATP

Total: 30 ATP

E. Coli is bacteria, and bacteria use their plasma membranes to establish a proton gradient for the electron transport chain. The 2 NADH they produce enters the same step of the ETC as the other NADH, meaning they get 2.5 ATP/all NADH (so add an extra 2 to the glycolysis NADH for a total of 32 ATP)

Eukaryotic Cardiac Muscle Cells and Hepatocytes have an efficient transport mechanism that allows their NADH from glycolysis to also enter the ETC as other NADH, so they also produce 32 ATP per glucose.

The number 36 comes from rounding to 2 ATP/FADH2 and cytoplasmic NADH, and 3 ATP/NADH. For Bacteria/Hepatocytes/Cardiac Muscle Cells, this number would be 38.

I read somewhere to assume 36 ATP/Glucose on MCAT unless stated other wise. If someone else could clear this up, that'd be great.

 

[FeinMS]

Glycolysis: 2 ATP, 2 NADH
PDC: 2 NADH
Kreb's Cycle: 2 GTP, 2 FADH2, 6 NADH

NADH from Cytosol: 1.5 ATP/NADH (enters Electron Transport Chain at the same step as FADH2, one step later than NADH. This leads to less ATP per molecule)
NADH in Mitochondria: 2.5 ATP/NADH
FADH2 in Mitochondria: 1.5 ATP/FADH2

So we have:
2 ATP
2 GTP --> 2 ATP
2 NADH (Cytosol) * 1.5 = 3 ATP
8 NADH (Mitochondria) * 2.5 = 20 ATP
2 FADH2 (Mitochondria) * 1.5 = 3 ATP

Total: 30 ATP

E. Coli is bacteria, and bacteria use their plasma membranes to establish a proton gradient for the electron transport chain. The 2 NADH they produce enters the same step of the ETC as the other NADH, meaning they get 2.5 ATP/all NADH (so add an extra 2 to the glycolysis NADH for a total of 32 ATP)

Eukaryotic Cardiac Muscle Cells and Hepatocytes have an efficient transport mechanism that allows their NADH from glycolysis to also enter the ETC as other NADH, so they also produce 32 ATP per glucose.

The number 36 comes from rounding to 2 ATP/FADH2 and cytoplasmic NADH, and 3 ATP/NADH. For Bacteria/Hepatocytes/Cardiac Muscle Cells, this number would be 38.

I read somewhere to assume 36 ATP/Glucose on MCAT unless stated other wise. If someone else could clear this up, that'd be great.

Yup I think I read 36 too.

 

[onedirection]

So we say that prokaryotes produce 38 and eukaryotes produce 36 officially?