1. Hey Guest! Check out the 3 MCAT Study Plan Options listed in the 'stickies' area at the top of the forums (BoomBoom, SN2ed, and MCATJelly). Let us know which you like best.

    Also, we now offer a MCAT Test-Prep Exhibitions Forum where you can ask questions directly from the test-prep services.
    Dismiss Notice
  2. Dismiss Notice
  3. Download free Tapatalk for iPhone or Tapatalk for Android for your phone and follow the SDN forums with push notifications.
    Dismiss Notice
Dismiss Notice

Interview Feedback: Visit Interview Feedback to view and submit interview information.

Interviewing Masterclass: Free masterclass on interviewing from SDN and Medical College of Georgia

Dismiss Notice
Hey Texans—join us for a DFW meetup! Click here to learn more.

AAMC Practice Exam Q. 49 and 50

Discussion in 'MCAT Discussions' started by squash_fan, Aug 7, 2015.

  1. squash_fan

    Mar 21, 2015
    Likes Received:
    Medical Student (Accepted)
    49) I'm not understanding why the stabilization is due to Aspartate rather than arginine. I initially thought the positive charge on arginine could be responsible for stabilizing the negative charge on OH groups on pantothenate.

    50) For this question, the ADP is stabilized by positive charges on His and Arg. Why is this stabilization due to positive charges instead of the negative charges like in Q. 49? Am I misunderstanding something?

    Please help. Thank you! :)
  2. Note: SDN Members do not see this ad.

  3. catie_jane

    2+ Year Member

    Jun 12, 2015
    Likes Received:
    Medical Student
    I don't remember these questions exactly (took the practice test over 1 month ago) but based on what you've written..

    1) Aspartate (or aspartic acid) is polar like the -OH group on pantothenate and polar likes to surround itself with like charges/polarity.

    2) ADP is stabilized by positive charges because the phosphate groups we know are negatively charged, therefore they need a positive charge to stabilize.

    I believe the difference between the two questions is that the -OH group in the first question is not actually deprotonated (therefore no negative charge), so the polar group will be attracted to similar polar groups

Share This Page