Based on the above, under standard conditions, could you get ATP out of this reaction in the direction stated (i.e., is the reaction favorable)?
[ Select ]
no
yes

If not, which other electron donor, instead of NADH, could make the reaction favorable?
[ Select ]
acetate
succinate
reduced ferredoxin
hydrogen
NADH can do this reaction

Question

Based on the above, under standard conditions, could you get ATP out of this reaction in the direction stated (i.e., is the reaction favorable)? 
[ Select ]
no
yes

If not, which other electron donor, instead of NADH, could make the reaction favorable? 
[ Select ]
acetate
succinate
reduced ferredoxin
hydrogen
NADH can do this reaction

BlackTom AI · Accepted Answer

NADH has a sufficiently negative reduction potential to drive the stated reaction, so the answer is yes, and no alternative donor is required (NADH can do this reaction).

1) Relevant concepts
- Redox reactions under standard biological conditions are judged by the difference in standard reduction potentials (ΔE°').  
- Free energy change: ΔG°' = -nFΔE°', where n = electrons transferred, F = 96.485 kJ·V−1·mol−1, and ΔE°' = E°'(acceptor) − E°'(donor). A positive ΔE°' gives a negative ΔG°' (favorable).  
- ATP synthesis requires a negative ΔG large enough to drive phosphorylation (≈ +30.5 kJ·mol−1 standard; physiologically often ~+50 kJ·mol−1 per ATP).

2) Step-by-step reasoning
- Biological NADH/NAD+ standard potential: E°' ≈ −0.32 V. If the intended electron acceptor has a more positive E°' than −0.32 V, then ΔE°' > 0 and the reaction is exergonic.  
- Example calculation with a common acceptor (O2/H2O, E°' ≈ +0.82 V) to illustrate magnitude:
  - ΔE°' = 0.82 − (−0.32) = 1.14 V
  - n = 2 electrons transferred per NADH
  - ΔG°' = −n F ΔE°' = −2 × 96.485 kJ·V−1·mol−1 × 1.14 V ≈ −220 kJ·mol−1
  - −220 kJ·mol−1 is highly exergonic and could theoretically drive synthesis of multiple ATP (far exceeding the ~+30–50 kJ required per ATP).

3) Why the correct answer is correct
- Because NADH’s E°' (~−0.32 V) is sufficiently negative relative to typical biological acceptors, the electron flow from NADH to such acceptors yields a positive ΔE°' and therefore a large negative ΔG°' — making ATP formation thermodynamically favorable. Thus NADH can drive the reaction in the stated direction under standard conditions.

4) Why the other options are incorrect (briefly)
- Acetate and succinate: these are poorer electron donors for many acceptors (their relevant redox couples are less reducing or are involved in different metabolic steps), so they would generally not provide a larger ΔE°' than NADH and thus may not make the reaction more favorable.  
- Reduced ferredoxin and hydrogen: these are actually stronger (more negative) donors than NADH and in many systems could also drive the reaction; however, the question asked which other donor would be needed instead of NADH to make the reaction favorable — because NADH already suffices, selecting one of these is unnecessary.  
- The best single statement consistent with the data is that NADH can do this reaction.

Conclusion: The reaction is favorable under standard conditions (yes), and NADH can perform the electron donation to make the reaction proceed (NADH can do this reaction), matching the provided answers.

类似问题

Diatoms are single-celled photosynthetic microalgae. How do diatoms obtain energy to carry out cellular work?

The process of resynthesizing adenosine triphosphate (ATP) from adenosine diphosphate (ADP) is called?

Question at position 13 In chemiosmosis, what creates ATP?Pyruvate dehydrogenaseOxaloacetateRubiscoATP synthaseprotein complexes

ATP formation:

As the electron moves from PSII to PSI, H+ ions are released contributing to a proton gradient inside the thylakoid space. What compound is ultimately produced from the proton gradient? (Choose ONE correct answer)

Peter Mitchell was a famous scientist who

ATP is made from adenosine diphosphate by addition of a phosphate.

22. Energy for metabolism can be stored in which of the following?

更多留学生实用工具

智能学习助手

风格化写作助手

论文查重助手

文献引用助手

课堂转译助手

课堂笔记助手

Quiz搜索助手

学校历年真题

智能刷题助手

智能匹配练习

希望你的学习变得更简单