Biochem Q bank 9

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Biochem Q bank 9

Postby MCAT_Retaker » Fri Jul 06, 2018 6:45 pm

Question 5

Can you further explain this question
is MDA only used for oxidation of specific products?
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Re: Biochem Q bank 9

Postby NS_Tutor_Alex » Sat Jul 07, 2018 5:51 pm

Hi MCAT_Retaker,

Thank you for the question. The reason why measuring MDA levels is objectionable as an indicator of total oxidative stress in a cell is because it's only one of 3 by products. Because the question stem is asking specifically for total cellular oxidative stress and not just oxidative stress from MDA, measuring it would not provide the whole picture. In order to assess total oxidative stress, there would need to be quantitative data for all 3 possible byproducts. As a hypothetical scenario, imagine if only 5% or 10% of the byproducts were MDA and the other 90ish% were the other two byproducts. There would seem to be little oxidative stress if we were only measuring MDA (which is what is happening in the passage experiment!), but in reality there could be a large amount of cellular oxidative stress from the other unmeasured byproducts.

Hope that helps, good luck with your studying!


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