Krebs cycle, ETC, fermentation, Glycolysis???

[dreams]

Do we have to know each step in all of these? Just wondering what I should concentrate on?

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[RSAgator]

I don't think so you need to know each step, but it is important to know what the net reactions from each are and the differences between them.

 

[coffeebythelake]

Don't worry. Even if you don't need to learn it completely for the MCAT you will have the pleasure of doing so in med school.

 

[Vihsadas]

It couldn't hurt to know the basics of every step. Learning the intermediates might be useful, and also the products of the co-reactions for the various steps (i.e. ATP, NADH, GTP, FADH2, CO2).
You should definitely learn how many ATP are produced in both glycolysis and the TCA. You should definitely learn how many NADH and FADH2 are produced. You should definitely learn how this happens: via electron transport chain: oxidation of NADH and FADH2 to reduce molecular O2 to water, which forms an H+ gradient across the IMM thereby powering ATP synthase to make ATP.
You should understand when glycolysis goes to fermentation and when it doesn't. You should understand why this happens. And you should understand why the body regenerates NAD+ during fermentation during the step from Pyruvate => Lactate.

 

[davidianstyle]

It couldn't hurt to know the basics of every step. Learning the intermediates might be useful, and also the products of the co-reactions for the various steps (i.e. ATP, NADH, GTP, FADH2, CO2).
You should definitely learn how many ATP are produced in both glycolysis and the TCA. You should definitely learn how many NADH and FADH2 are produced. You should definitely learn how this happens: via electron transport chain: oxidation of NADH and FADH2 to reduce molecular O2 to water, which forms an H+ gradient across the IMM thereby powering ATP synthase to make ATP.
You should understand when glycolysis goes to fermentation and when it doesn't. You should understand why this happens. And you should understand why the body regenerates NAD+ during fermentation during the step from Pyruvate => Lactate.

Just browsing the forum and saw this thread. Thanks for the info, Vihsadas!

 

[Rofeh20]

The AAMC rarely tests these topic directly. In general here's the points you need to know:

• Know the glycolysis reaction
• Know the purpose of fermentation (to regenerate NAD+)
• Know where in the cell glycolysis & fermentation occur relative to pyruvate decarboxylation/TCA/ETC
• Understand the purpose of TCA (to generate electron carriers)
• Understand the purpose of ETC (to create proton gradient)
• Understand how ATP is synthesized

The AAMC is not really interested in your ability to memorize specific numbers or reactions. Furthermore, recent evidence has cast doubt on the old textbook idea that 36-38 ATP are generated from the breakdown of glucose.

In short, take a macroscopic view. The whole point of this process is to create ATP. Glucose essentially undergoes a combustion reaction for the purpose of setting up a proton gradient, which in turn is necessary for the synthesis of ATP. If you understand the big picture, you're set for a passage that decides to zoom in on a particular facet of this process, and/or to experimentally mess around with this setup.