Hi Shauna,

This is a bit tough, but the logic would be that the reactivity of oxygen is most important to the

In particular, oxygen in not the only species that is available to be used as a terminal acceptor, and the most compelling reason to use it is because of its inherent electron accepting activity.

When you say oxygen is used because of its availability within the matrix, you open a can of worms implying that anything that gets in should be able to react. Other gases such as nitrogen/carbon dioxide can also get in, but they're not as good at being electron acceptors as oxygen, and so they are not used.

That being said, I'm not sure I would have gotten this off the bat. The logic is solid, but I think it would trip up a lot of people on exam (myself included)

I hope this helps!

Katt

Hi Shauna,

Based on my experience, it is certainly possible, but I would call this particular instance espeically a much harder question.

It's harder than the MCAT generally goes for the biochem section, and even if it is included, I'd say the majority of people would not get those types of questions.

As a result, I think it's more of a difference between a 128 and higher on that section rather than the difference between 125 to 128.

So again, it's something to be on the lookout for, but I wouldn't prioritize it.

I hope this helps!

Katt