**Official August 2017 MCAT Thread**

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owlsandturtles

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I haven't seen a thread for August yet so I thought I'd start one!

How is everyone's study schedule looking?

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Hey guys!! I have a quick question about this and would really appreciate if someone can help me.

1) Which amino acid is LEAST likely to associate with lysine in the active site of an enzyme?
A) D
B) E
C) S
D) R

Answer: D
"Both Aspartic acid (D) and glutamic acid (E) are negatively charged at physiological pH, so they would be very likely to associate with a positively charged lysine residue. Because the question asks for the amino acid LEAST likely to associate with lysine, A and B must be eliminated. Serine (S) is a polar amino acid, so it too is likely to associate with a positively charged lysine, eliminating Answer C. Finally, arginine (R) is positively charged at physiological pH. Therefore it would be repelled by the positively charged lysine, making Answer D the correct choice."


2) The amino acids Asp6, Asn9, Thr10, His11, and Arg27 are found near the ADP binding site of PanK3. Which two amino acids contribute to the stabilization of ADP binding described in the passage?

1) Asn9 and Thr10
2) His11 and Arg27
3) Asp6 and Arg27
4) Asp6 and His11

Answer: B
"The answer is B because both His and Arg side chains can carry a positive charge. They would have favorable ionic interactions with the negatively charged phosphates of ADP.


So I always thought that amino acids are likely to interact with SIMILAR amino acids (acidic with acidic, basic with basic, etc.) I thought this was a general rule of thumb until I got both of these questions wrong.
 
Hey guys!! I have a quick question about this and would really appreciate if someone can help me.

1) Which amino acid is LEAST likely to associate with lysine in the active site of an enzyme?
A) D
B) E
C) S
D) R

Answer: D
"Both Aspartic acid (D) and glutamic acid (E) are negatively charged at physiological pH, so they would be very likely to associate with a positively charged lysine residue. Because the question asks for the amino acid LEAST likely to associate with lysine, A and B must be eliminated. Serine (S) is a polar amino acid, so it too is likely to associate with a positively charged lysine, eliminating Answer C. Finally, arginine (R) is positively charged at physiological pH. Therefore it would be repelled by the positively charged lysine, making Answer D the correct choice."


2) The amino acids Asp6, Asn9, Thr10, His11, and Arg27 are found near the ADP binding site of PanK3. Which two amino acids contribute to the stabilization of ADP binding described in the passage?

1) Asn9 and Thr10
2) His11 and Arg27
3) Asp6 and Arg27
4) Asp6 and His11

Answer: B
"The answer is B because both His and Arg side chains can carry a positive charge. They would have favorable ionic interactions with the negatively charged phosphates of ADP.


So I always thought that amino acids are likely to interact with SIMILAR amino acids (acidic with acidic, basic with basic, etc.) I thought this was a general rule of thumb until I got both of these questions wrong.
You're somewhat correct in your thinking in that nonpolar amino acids will tend to interact with other nonpolar amino acids, polar will interact with polar, and charged will interact with charged - but you're not going to find a biological system or physical system where a positive charge will choose to interact with another positive charge instead of a negative charge. Like charges always repel, opposite charges always attract.
 
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2) The amino acids Asp6, Asn9, Thr10, His11, and Arg27 are found near the ADP binding site of PanK3. Which two amino acids contribute to the stabilization of ADP binding described in the passage?

1) Asn9 and Thr10
2) His11 and Arg27
3) Asp6 and Arg27
4) Asp6 and His11

Answer: B
"The answer is B because both His and Arg side chains can carry a positive charge. They would have favorable ionic interactions with the negatively charged phosphates of ADP.

And to expand on this question and what blackroses was saying- Histidine and arginine both have positive charges, you're correct. But the two AA residues aren't interacting with each other in the active site; they're acting on the substrate ADP. In fact, I think their side chains are on opposite sides of the active site (not entirely sure, but beside the point). So you would want something that can interact with the negative charges on ADP. Therefore, the answer is B, the positive charged AAs.
 
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And now we wait...

I can only hope the C/P section I took has a very generous curve. It was brutal!
 
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I took my exam yesterday and my brain is a puddle now. I had taken the old version, but this was my first experience with the new exam. Comparatively, I feel like the new exam is more difficult in certain ways, but easier in others. I found the passages on the new MCAT to be much more dense in terms of content, but I finished each section with at least five minutes to spare. Having that extra time on each section really allows for you think deeply into what the passages are saying...but that also means the test creators can make the passages more difficult! But, like I said, you have time to go back and reference/reread the passages and pick up on little details that you missed on your first read. I feel like the time limit on the old exam was really holding me back from doing as well as I could have. Now, if I get a subpar score, it's purely my own fault. :p

Here's to waiting for a month!
 
And now we wait...

I can only hope the C/P section I took has a very generous curve. It was brutal!
OMG I thought it was just me! It was AWFUL! I thought CARS wasn't too bad, but I also got a passage about a certain skill that I actually have...so I breezed through those particular questions.
 
OMG I thought it was just me! It was AWFUL! I thought CARS wasn't too bad, but I also got a passage about a certain skill that I actually have...so I breezed through those particular questions.
I actually felt pretty good about all the sections except for C/P - it probably doesn't help that 1. it's the first section of the day, 2. it's always my worst section, and 3. I'm painfully slow at math. I still felt like there were a few really weird off-the-wall questions, plus a couple that were essentially just unit conversions, but were nightmare-length.

Edit: just took a peek at the subreddit for yesterday - it would seem that everyone is quite unhappy with the C/P section! Hopefully that means a generous curve!
 
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Glad I'm not the only one who got thrown off by the CP section. That section was really challenging, decidedly more so than any of the AAMC practice exams or the AAMC section bank. It was funny, though: some of the questions felt like throwaways while the others were brutal. There were practically no "medium" difficulty questions. Also whoever says there are such things as high yield and low yield concepts is lying. Study everything.

I thought CARS was more or less average in difficulty and on par with the AAMC exams.

The BB section was okay. It felt a bit harder than the practice AAMC exams but about even with the Section Bank Q's (which I thought were a notch up from AAMC's practice exams). Hopefully my 6 NS exams prepared me for this. Again, there is no such thing as a high or low yield concept.

PSB section I felt was also roughly on par with AAMC material; again, more similar to the section bank than the practice exams and thus a bit more difficult.

Overall: My NS average was 509 on the dot (n=6), AAMC 1 was a 511 and AAMC 2 was a 513 (AAMC sample was 84% correct). Walked out of this exam expecting a 506 or so. Almost voided. It was just an all around disappointment and felt nothing like the 600 hours of review and thousands of practice questions I put into this summer. Hopefully the scale is generous where it needs to be.

Regardless, the AAMC needs to do a better job of releasing more material reflective of the exam. To open with a CP section like that was just inhumane.
 
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Felt like I had 8 section bank type passages for B/B section. Cars is my weakest section but felt it was easier than usual
 
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Anybody else take the test today? Felt like I had 8 section bank type passages for B/B section. Cars is my weakest section but felt it was easier than usual
Yea I tested today and felt that too. Psych was harder than usual as well...hopefully the curve for CARS is still good!
 
Yea I tested today and felt that too. Psych was harder than usual as well...hopefully the curve for CARS is still good!
I felt like the Psych you could narrow it down to 2 answers but both would make sense. At that point, it was picking the least wrong one. But I'm worried about B/B. Did you have trouble with it also ??
 
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Just want to point out; the last few posters were hoping for a generous curve on specific sections of the test. The AAMC doesn't curve the MCAT grade. See the official website. Just saying.
Having said that, I also felt C/P was way harder than practice AAMC tests, as seems to be a consensus here.
Hopefully we did ok enough to be accepted to school. After that, chances are that no one will ever ask you for your MCAT score again, so it won't matter!
 
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Anybody else take the test today? Felt like I had 8 section bank type passages for B/B section. Cars is my weakest section but felt it was easier than usual

I tested today. It was an interesting exam. The first half of CP felt kinda easy. Second half was more challenging and there was one passage that got real nasty. Was surprised at how many giveaway discretes there were.
CARS was not great. Just didn't like it much. Bio was tough but hit my content strengths. Felt really good about it until the end after hitting some pathway passages that were not a good time. PS I just don't know. Recognized all the terminology but the familiar stuff was presented in very weird ways. Heavy exp/study analysis. Wasn't easy.
Overall, it could've been worse andnit could've been better.
 
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I tested today. It was an interesting exam. The first half of CP felt kinda easy. Second half was more challenging and there was one passage that got real nasty. Was surprised at how many giveaway discretes there were.
CARS was not great. Just didn't like it much. Bio was tough but hit my content strengths. Felt really good about it until the end after hitting some pathway passages that were not a good time. PS I just don't know. Recognized all the terminology but the familiar stuff was presented in very weird ways. Heavy exp/study analysis. Wasn't easy.
Overall, it could've been worse andnit could've been better.
Similar experience here, especially with CP. I guess there is so much they they can test on in all sections that it is virtually impossible to be fully prepared. Hard to think on the fly as well under exam pressure.
Good luck all!
 
Just want to point out; the last few posters were hoping for a generous curve on specific sections of the test. The AAMC doesn't curve the MCAT grade. See the official website. Just saying.
Having said that, I also felt C/P was way harder than practice AAMC tests, as seems to be a consensus here.
Hopefully we did ok enough to be accepted to school. After that, chances are that no one will ever ask you for your MCAT score again, so it won't matter!

The AAMC normalizes the scores (hence our receiving scaled scores as opposed to raw percentages) based on the performance of everyone who took a particular exam. AAMC's website refers to this as "equating."
 
The AAMC normalizes the scores (hence our receiving scaled scores as opposed to raw percentages) based on the performance of everyone who took a particular exam. AAMC's website refers to this as "equating."
Yup, true! But that is all based on the past two years data, until May of this year. So it's not as sharp a "curve" as would be if all test takers this week or month would be taken into account as one group. I think we are agreeing in essence....
 
Just want to point out; the last few posters were hoping for a generous curve on specific sections of the test. The AAMC doesn't curve the MCAT grade. See the official website. Just saying.
Having said that, I also felt C/P was way harder than practice AAMC tests, as seems to be a consensus here.
Hopefully we did ok enough to be accepted to school. After that, chances are that no one will ever ask you for your MCAT score again, so it won't matter!


They do not "curve" after test day, but they "scale and equate".
 
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They do not "curve" after test day, but they "scale and equate".

I see your point. :). I guess "scaling and equating" against a yearly cohort is almost the same as "curving" within each test batch.
But, it is almost the same perhaps, not exactly. Firstly, since the number of students in the "scaling and equating" cohort is 150,893 as per AMCAS, chances are there were quite a few students who got some more tricky C/P questions right, and the "curve" may turn out to be much less steep than it would have been considering only the cohort writing this week or month. That may be only a very minor difference though. Second, there is no correction for hard questions given this year until after next May, since all those questions deemed to be in the same categories as last two years will still be scored the same, until proven by us to be more difficult, so next year's students will get the curve on those questions, not us.
 
I see your point. :). I guess "scaling and equating" against a yearly cohort is almost the same as "curving" within each test batch.
But, it is almost the same perhaps, not exactly. Firstly, since the number of students in the "scaling and equating" cohort is 150,893 as per AMCAS, chances are there were quite a few students who got some more tricky C/P questions right, and the "curve" may turn out to be much less steep than it would have been considering only the cohort writing this week or month. That may be only a very minor difference though. Second, there is no correction for hard questions given this year until after next May, since all those questions deemed to be in the same categories as last two years will still be scored the same, until proven by us to be more difficult, so next years students will get the curve on those questions, not us.
Actually, what that post is saying is that they do make adjustments to scores for people who sat for a particular test before their score is released. Their scaling does affect people who just took the test.
 
Actually, what that post is saying is that they do make adjustments to scores for people who sat for a particular test before their score is released. Their scaling does affect people who just took the test.
They are saying that they adjust the weight of the questions so that everyone in a particular year will end up with an equally meaningful score, based on the data from before last May. While it is true that if you had an especially difficult test with many hard questions, those questions will weigh less, that is still not a "curve". First, it is not likely that your test was way harder than it currently was for everyone else, rather it is more likely that there small fluctuations in difficulty. Also, if more people tend to find a certain type of question harder this time around, they will only consider this data in the scoring for next year. They do adjust it before it is released, based on people who sat for it before last May. It is not very likely that more than a couple questions on C/P will weigh less because of scaling and equating. So if there was a lot of difficult encountered on C/P for example, I wouldn't bet on scaling and equating to save the day.
 
They are saying that they adjust the weight of the questions so that everyone in a particular year will end up with an equally meaningful score, based on the data from before last May. While it is true that if you had an especially difficult test with many hard questions, those questions will weigh less, that is still not a "curve". First, it is not likely that your test was way harder than it currently was for everyone else, rather it is more likely that there small fluctuations in difficulty. Also, if more people tend to find a certain type of question harder this time around, they will only consider this data in the scoring for next year. They do adjust it before it is released, based on people who sat for it before last May. It is not very likely that more than a couple questions on C/P will weigh less because of scaling and equating. So if there was a lot of difficult encountered on C/P for example, I wouldn't bet on scaling and equating to save the day.
Actually they never specify if they're only comparing the data to administrations prior to the beginning of the "new testing year". Additionally, if people find a particular type of question difficult, that question type might not be accounted for directly, but the corresponding drop in total scores across the board will be accounted for, which has the same end effect for testers. Finally, let's not nitpick about what the technical definition of a curve is, I think it's pretty clear what everyone means when they call it a curve - it's easier than typing out "scaling and equating" every time.
 
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AAMC is very vague about exactly what goes into their 'curve.' While I do agree that there's probably not much deviation in terms of the scale, I think even adjusting by 3-4 questions can make a world of difference in terms of what you get as a score. I think it's a combination of tested questions they have used in the past to determine the correct #, as well as how testers did on a certain test day.

I assume they certainly have to adjust if testers do badly on a certain day compared to what was expected. They had an AMA on MCAT section of Reddit, but they were very transient about the whole process. 30-35 days is not warranted to grade an exam especially if they supposedly have no 'curve.'
 
Look people, it most definitely has nothing to do with how well testers did on a certain day, and the scores are definitely not manipulated so as to fit a Gaussian bell curve. If you don't want to believe the AAMC that's fine, no difference to me, but that is what they clearly state on their website How is the MCAT Exam Scored?.
What is not clearly stated is the actual process of equating, but it is described as a technique for ensuring equal difficulty on all exam sets. This serves to equalize any small fluctuations in difficulty between question sets. The probability that any one of us received a disproportionately large number of questions that were more difficult than average is slim indeed. So, besides for being a shorter word that is easier to type (which is absolutely true), equating will also not change your score anywhere near as much as a curve would.
Let me add one more point. The people who were satisfied (or at least not that disgruntled) with their C/P section probably did not go vent on Reddit after the exam about this, so the "everyone" who you saw complaining was probably not representative of the population of test takers, i.e. a sampling bias.
So, what I was saying was, and I promise I won't say it again :smuggrin:, was that if "everyone was quite unhappy with the C/P section" on a particular day, this would not necessarily result in a "generous curve".
On the other hand, I really and truly hope that you, and I for that matter, did well overall! We're all in this together, and honestly I too found C/P to be more difficult than I anticipated, unlike the rest of the exam. I am just not counting on benefiting form a curve, and I don't think I'll end up with a great score in that section. Oh well, I did my best.
Wishing you best of luck with the rest of the process!
 
The AAMC normalizes the scores (hence our receiving scaled scores as opposed to raw percentages) based on the performance of everyone who took a particular exam. AAMC's website refers to this as "equating."

They set the exam scales before the the test is administered. There's no performance based scale on the mcat. They got asked about this a bit on the AMA they did on Reddit recently.
 
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Similar experience here, especially with CP. I guess there is so much they they can test on in all sections that it is virtually impossible to be fully prepared. Hard to think on the fly as well under exam pressure.
Good luck all!

Definitely. I was expecting something completely awful walking in so it was a slightly relieveing in some ways. Just hope scores don't deviate too much from practice tests on the low end.
 
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Need 125 on all subsections for University of Alberta app - hoping for a generous curve on the B/B section.
 
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I'm embarressed to admit how many times I've mentally calculated my score and Or changed my mind about how I did.

August 24th MCAT taker here! You are NOT alone! At the end of my P/S section, I was writing down what score I was expecting to get hahah. That score has changed in my mind a few times over the past 24 hours.. Here's to waiting!
 
Well, I just finished writing mine today, glad to have gotten that over with!

Based on how I felt and did on practice exams, I came out feeling like I scored 516 or so. I felt that phys/org was harder than on practice, and the rest was similar difficulty to AAMC practice exams.

Just for comparison, in case it might be helpful for anyone of you, my stats for practice are:

AAMC sample test (percentage score) July 6:
63%|87%|86%|81%

AAMC practice exam 1 (ranked score) July 19:
127|129|132|127 = 515

TPR demo test (free) (~ranked score~) July 27:
124|127|126|129 = 506

AAMC practice exam 2 (ranked score) August 9:
129|130|131|129 = 519

And now the real thing...... if it's 515 or above I'll be happy.

Good luck to all of us!

Update:
And now for my real scores. Just got them in right now.

August 11, 2017
130|129|132|130 = 521, 99th percentile

I am surprised, happy, and floored! Now the nervous wait for invitations.....
Good luck to you all!! I mean it!
 
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Update:
And now for my real scores. Just got them in right now.

August 11, 2017
130|129|132|130 = 521, 99th percentile

I am surprised, happy, and floored! Now the nervous wait for invitations.....
Good luck to you all!! I mean it!
congrats!!!
 
8/18 scores are out!

CP: 127
CARS: 128
BB: 126
PS: 127
Total: 508 (Previous MCAT scores: 26, 27, 31)

All in all, a fairly balanced score. No one section is glaringly worse/better than any other section. Not quite as high as I was hoping for, but I'm fairly comfortable applying to my school of choice with this, as it is only one point lower than their 2016 incoming student average MCAT. I mean, yeah, I'm a little "meh" about it, but it could have been a lot worse! I'm kind of surprised my CP wasn't lower; that section was ROUGH. And yes, this was my 4th time writing, so I have every reason to want to be done with this God-forsaken exam, lol. Now I just need to focus on doing as well as possible in my physiology masters program and getting awesome LoRs.
 
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