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Q about my "thought process and/or logic" about insulin question

Discussion in 'MCAT Study Question Q&A' started by i4171, 05.05.12.

  1. i4171

    i4171

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    this is from br cbt.

    New studies are indicating that the micronutrient chromium picolinate appears to normalize blood sugar levels in Type II diabetics who are not on any other diabetic therapy. Chromium picolinate must therefore:

    A. increase the effectiveness of insulin.
    B. impair glucose uptake.
    C. prevent pancreatic β-cells from secreting insulin.
    D. act as an appetite suppressant, thereby decreasing the overall blood glucose.

    The answer is A but I put C as a guess.
    I initially crossed out A because the way I interpreted it was, insulin circulating is already as effective as it can be and since no "biomolecular changes" are being made, the insulin alone is already at its "fullest potential." the only way Chromium picolinate would work is by somehow changing the way the insulin receptors on the cells respond, not the insulin itself. So if anything, it was the effectiveness of the insulin receptor. Now that I know the answer is A, I realize the way meant "increase the effectiveness" had a little different meaning than what test writer had in mind. I think if the answer choice said something along the lines of "increase the effectiveness of the insulin and insulin receptor function" than it would've been more clear.

    The AAMC tends to be more simple while people claim the real MCAT is a little tougher. I know BR tends to make their questions a little more thought provoking too and more in depth along with the real MCAT (which I'm glad for), do you guys ever run into issues like this? I know this is just one problem and I'm not freaking out over this, but I just wanted to see if you guys think my logic or thought process is flawed here?

    Thanks!
  2. dsoz

    dsoz Accepted OHSU C/O 2017

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    Think of it as an elimination of wrong answers type of question. Eliminate B, C, and D as being bad answers and you are left with only A left.

    B. why would you want to make the T2 DM worse?
    C. that would make it into T1 DM.
    D. Diet pill? no thanks.

    dsoz
  3. Morsetlis

    Morsetlis SGU MS-4

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    Type 2 DM involves high fasting blood glucose due to insulin resistance, but there is still a basal low level of insulin secretion by the beta cells of the pancreas. The two prototypical drugs used to treat it are metformin (increases insulin sensitivity of tissues) and sulfonylureas (stimulate insulin secretion by the beta cells).

    Insulin is required for the insulin-dependent uptake of glucose into tissues (i.e. muscles) by GLUT-4 transporters.

    If you impair insulin secretion the hyperglycemia will be worse, not better.

    Remember that in Type 2 DM, insulin is NOT effective because there is INSULIN RESISTANCE.
  4. Dasypus

    Dasypus

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  5. i4171

    i4171

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    oh yeah, the reason why I guessed C (before knowing the answer) was because the question said, "chromium picolinate appears to normalize blood sugar levels" so thinking that in type 2, theres can excess blood sugar so decreasing insulin release will help alleviate the excess blood sugar level.

    i think if i went from D to A, then I mightve gotten A but when I first hit A, i was so sure that it was wrong (based on what I said in my OP). i guess i just need to think through the answer choices more


    edit:
    and the question didnt really say anything else about actually improving the negative effects of type 2 (failure of uptake of glucose). all i was concerned about in that question was finding something "that normalize blood sugar levels."
  6. Morsetlis

    Morsetlis SGU MS-4

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    Insulin does not increase blood sugar level, so there is some failure in your logic of how insulin works. The substances that increase blood sugar level are glucagon, cortisol, and growth hormone. Insulin rises are a RESPONSE to increasing blood sugar level, such as from a meal.

    Type 2 DM has high blood sugar. Therefore, one of 3 (or more) things must be true:
    -They are not making enough insulin
    -Their insulin is not as effective as normal
    -Their tissue is not responding as effectively as normal to insulin

    To normalize the blood sugar (reduce it from the high levels), the drug must do one of 3 things:
    -Make more insulin
    -Make insulin more effective
    -Make tissues respond more to insulin

    Only one of the choices is represented.
  7. i4171

    i4171

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    thank you!
  8. EnginrTheFuture

    EnginrTheFuture

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    I picked A over D out of biochem instinct but I was wondering if anyone knew why D isn't valid. Is it because lowering the blood glucose through dietary changes would cause issues with cells not receiving the glucose it needs?
  9. Morsetlis

    Morsetlis SGU MS-4

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    Because it is one step removed from the process and introduces new variables (requires the pt to not-eat, which isn't mentioned in the stem).

    Not eating isn't that effective or useful in type 2 DM anyway. You want 2 goals: get glucose into tissues, and reduce blood glucose. Starving only helps with one, and probably not all that much.

    That answer is a distractor.
  10. EnginrTheFuture

    EnginrTheFuture

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    Had a feeling that was the case and avoided it like the plague.

    Thanks!

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