Bio Destroyer ques # 120 with question written

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Hey guys, i'm doing the Destroyer and i got this question wrong. I looked it up in the solutions in the back but i still didn't get it. Why C is the answer and how many ATP that it generates?
# 120
Which process(es) generates the most ATP?
a) Glycolysis
b) Gluconeogenesis
c) Electron transport chain
d) TCA cycle
e) A and D are approximately equal
 
Hey guys, i'm doing the Destroyer and i got this question wrong. I looked it up in the solutions in the back but i still didn't get it. Why C is the answer and how many ATP that it generates?
# 120
Which process(es) generates the most ATP?
a) Glycolysis
b) Gluconeogenesis
c) Electron transport chain
d) TCA cycle
e) A and D are approximately equal

Remember...Glycolysis makes a NET of 2 ATP per glucose. Then when you go onto the Krebs cycle, an additional 2 ATP are formed by way of GTP. Now in the electron transport chain...that is where you get all the ATPs formed from transferring electrons from the NADH (3 ATP generated PER NADH) and FADH2 (2 ATP generated PER FADH2 reduced) to the cytochromes and finally to O2. Therefore, even if there were only 1 NADH and 1 FADH2 reduced each, that would still generate MORE ATP than from glycolysis and krebs cycle combined. The electron transport chain makes the bulk of ATP. Think of glycolysis and krebs cycle just making the large quantities of NADH and FADH2 necessary to generate a large amount of ATP.
 
hi Optimism Smiles, i'm kinda confused as i read your explanation and look up the Kaplan blue book at the same time. It is quite contradicted to the Kaplan blue book. I'll copy the ATP production in Kaplan blue book in here, and some how i'm even more confused as i look more and more at it.

Eukaryotic ATP production per Glucose Molecule

Glycolysis
2 ATP invested -2 ATP
4 ATP generated +4 ATP (substrate)
2 NADH x x2 ATP/NADH +4 ATP (oxidative)

Pyruvate Decarboxylation
2 NADH x 3 ATP/NADH +6 ATP (oxidative)

Citric Acid Cycle
6 NADH x 3 ATP/NADH +18 ATP (oxidative)
2 DADH2 x 2 ATP/FADH2 +4 ATP (oxidative)
2 GTP x x1 ATP/GTP +2 ATP (substrate)

Total + 36 ATP

my question is: Since at the end of citric acid cycle, a total of 36 ATP is generated, then how come there is more ATP produced in the electron transport chain?
 
In Cliffs AP bio on page 46 there is a picture/chart that shows that in the Krebs cycle 2 ATP , 6 NADH, and 2 FADH2 are produced. But its not until the Electron transport chain that the electrons are passed down from one carrier to the next thus forming the ATP (24). Then if we add this number to the ones produced from the earlier step we would get a total of 36 ATP for cellular respiration.
 
hi Optimism Smiles, i'm kinda confused as i read your explanation and look up the Kaplan blue book at the same time. It is quite contradicted to the Kaplan blue book. I'll copy the ATP production in Kaplan blue book in here, and some how i'm even more confused as i look more and more at it.

Eukaryotic ATP production per Glucose Molecule

Glycolysis
2 ATP invested -2 ATP
4 ATP generated +4 ATP (substrate)
2 NADH x x2 ATP/NADH +4 ATP (oxidative)

Pyruvate Decarboxylation
2 NADH x 3 ATP/NADH +6 ATP (oxidative)

Citric Acid Cycle
6 NADH x 3 ATP/NADH +18 ATP (oxidative)
2 DADH2 x 2 ATP/FADH2 +4 ATP (oxidative)
2 GTP x x1 ATP/GTP +2 ATP (substrate)

Total + 36 ATP

my question is: Since at the end of citric acid cycle, a total of 36 ATP is generated, then how come there is more ATP produced in the electron transport chain?

It is not contradictory at all 🙂 In Glycolysis, you get 4 ATP. However, you used 2 ATP to put into glycolysis, so you get 2 NET ATP. This is ATP made solely from glycolysis itself. You also get 2 NADH produced from glycolysis. This isn't ATP yet...it has to be put into the electron transport chain to make ATP (Kaplan just included it here to show that the 2NADH made in glycolysis yields around 2 ATP each from the electron transport chain). This same thing goes for the Krebs Cycle and pyruvate decarboxylation. Only 2 ATP are made DIRECTLY from the Krebs Cycle. Krebs also produces 6NADH and 2 FADH2 which can only yield ATP once put into the electron transport chain. Hence, everywhere it says "oxidative" in that chart from Kaplan, that means that isn't ATP made DIRECTLY in glycolysis, pyruvate decarboxylation, or Krebs cycle, it is ATP made once NADH and FADH2 go to the electron transport chain.

I think you are confused because you are assuming you make MORE ATP once you go to the electron transport chain. This chart is showing the OVERALL picture (including what happens in the ETC). Every time NADH and FADH2 are involved, that is what is going to the electron transport chain to make ATP.
 
i have to say thanks a thousand times to you, Optimism Smiles😍. You answer my question right at the point which i don't understand🙂. You made it even clearer than Orgoman. Cellular respiration used to be the topic that i hate to review the most. I was even afraid to do practice test that is related to NADH, or FADH ... that stuff. Now after i get the whole thing, i think i'm more confident. Thanks Optimism Smiles, thanks MunecaDDS.... endless thanks...............
 
i have to say thanks a thousand times to you, Optimism Smiles😍. You answer my question right at the point which i don't understand🙂. You made it even clearer than Orgoman. Cellular respiration used to be the topic that i hate to review the most. I was even afraid to do practice test that is related to NADH, or FADH ... that stuff. Now after i get the whole thing, i think i'm more confident. Thanks Optimism Smiles, thanks MunecaDDS.... endless thanks...............

No problemo 🙂 I actually teach freshman biology to non-science people soooo I'm used to explaining biology to people who are confused on a daily basis! It's really fun! Maybe I should not apply to d-school and just make my own test-prep book? :idea: Good luck!
 
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