A little biochem help before the final

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The discussion centers around the calculation of ATP yield from the complete oxidation of glucose, which is typically stated to be around 30 ATP. The original poster outlines their calculations, detailing contributions from NADH, GTP, and FADH during the TCA cycle and glycolysis, ultimately arriving at a total of 32 ATP. They express confusion over the discrepancy with their professor's figure of 30 ATP, suggesting that the professor may have referred to net ATP yield after accounting for ATP used during glycolysis. Other participants in the thread comment on the complexity of biochemical abbreviations and the nature of biochemistry as a field focused on memorization of pathways and terms. The conversation highlights common misunderstandings in biochemical calculations and the importance of clarity in communication. The thread concludes with a note that it is an older discussion, implying that the original question may have been resolved long ago.
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I was wondering if someone could explain to me where all the ATP comes from from the complete oxidation of glucose. We said in class complete oxidation yields ~30ATP. I pretty much have where all the ATP comes from so far except my math is a little off.

We said in class 2.5 ATP come from NADH when e- 's are transferred to O2.

Thus in the TCA cycle I count 4 places where NADH is given off 4x2.5=10ATP
multiply that by 2 since there are two copies of pyruvate after glycolysis for 1 glucose molecule so there are 20ATP.

In another step in the TCA cycle 1 GTP is given off so 2x1GTP=2 NTPs.
That gives 22 ATPs

In another step in TCA cycle there is 1FADH given off, which we said in class yields 1.5 ATP, so 2x1.5=3 ATP

so we have 25 ATP.

4 NTPs from glycolysis

so 29 ATPs. Finally there is 1 cytosolic NADH that is given off during glycolysis. In class we said cytosolic NADH yields 1.5 ATP. So 2x1NADH=2NADHx1.5=3ATP

For a grandtotal of

32ATP. In the handout notes my prof. gave us he said there should be 30 ATP, where did I go wrong?
 
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Did you take into account that during glycolysis ATPs are used. 30 might be the net yield of ATP.

However, I remember that maximun net yield was 38 but your prof my give you the number in term of efficiency rather than theoritical.
 
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Ah yes that was it. Thanks for catching it. Such an easy mistake.
 
gravenewworld said:
I was wondering if someone could explain to me where all the ATP comes from from the complete oxidation of glucose. We said in class complete oxidation yields ~30ATP. I pretty much have where all the ATP comes from so far except my math is a little off.

We said in class 2.5 ATP come from NADH when e- 's are transferred to O2.

Thus in the TCA cycle I count 4 places where NADH is given off 4x2.5=10ATP
multiply that by 2 since there are two copies of pyruvate after glycolysis for 1 glucose molecule so there are 20ATP.

In another step in the TCA cycle 1 GTP is given off so 2x1GTP=2 NTPs.
That gives 22 ATPs

In another step in TCA cycle there is 1FADH given off, which we said in class yields 1.5 ATP, so 2x1.5=3 ATP

so we have 25 ATP.

4 NTPs from glycolysis

so 29 ATPs. Finally there is 1 cytosolic NADH that is given off during glycolysis. In class we said cytosolic NADH yields 1.5 ATP. So 2x1NADH=2NADHx1.5=3ATP

For a grandtotal of

32ATP. In the handout notes my prof. gave us he said there should be 30 ATP, where did I go wrong?

uh what maybe if you stopped the abriviations we could help you out?
 
Luongo said:
uh what maybe if you stopped the abriviations we could help you out?


Well, if you don't know what those abbreviations stand for, then you're not going to be able to help him anyways. :wink:
 
BoomBoom said:
Well, if you don't know what those abbreviations stand for, then you're not going to be able to help him anyways. :wink:

it looks like simple multiplication and addition with silly abbriviations is this what biochem is? lol
 
uh what maybe if you stopped the abriviations we could help you out?

1. If you don't know what ATP, TCA etc stand for, I don't think you're going to be very much help.

2. This thread is over four years old, I'm sure he has finished this class by now!
 
i think from bio 12 i remember atp is adenosinetriphosphate or something i don't know what TCA is or FAGH or NADS lol what kind of course is this? I'm glad i stuck with mathematics
 
They're all relatively basic abbreviations that most bio students learn in their first year, and yes, biochemistry basically consists of memorizing mundane chemical pathways and cycles, and knowing the abbreviations of the constituents.

Good thing I only decided to minor in bio :D
 
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Thread locked. Luongo necroposted.
 

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