The Official August 2015 MCAT Thread

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Registration opens up sometime today so I thought I'd go ahead and make this thread. Anyone else taking it in August?
 
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FOCUSandEARNit said:
Okay, I wouldn't be giving medical advice on this forum. 3 mg melatonin is MUCH more than the body actually needs. Evidence shows that the average adult male only needs 150 MICROgrams, thus you are taking potentially closer to 20x the needed amount.
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Okay, people shouldn't give medical advice on this forum. Got it.

FOCUSandEARNit said:
While melatonin is a natural substance, this should NOT be used for the first time the night before the exam without knowing how you feel the next morning.
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But didn't you just....I mean.....huh??? 😕


For the future, refs might be useful. Something like:
http://www.deborahburnett.com/images/uploads/MelatonininHumans.pdf
or
http://www.chronotherapeutics.org/docs/other/Zhdanova 1996.pdf

I am not surprised 3mg worked very well for @TexasSurgeon according to these papers.
 
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kanda1o said:
In other news.........

Aug 22nd tester here..... anyone else freaking out right now? Or confused on what they should be doing with two days left?


(I am..... so please give me advice)

THANK YOU 🙂
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I'm just sitting in class wishing I still had an extra week to zonk out like everyone else ITT lol. I'm doing jack sheit these next two days.
 
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So, I've always been confused by this, and I'd appreciate if anyone could help me out! The total increase in cross-sectional area of all capillaries combined decreases the velocity. However, Poiseuille's Law states that flow is directly proportional to pi*r^4. Wouldn't that mean that an increase in cross sectional area increases flow rate? Is there a difference between flow rate and velocity, or am I missing something here? Thanks in advance!
 
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pre.med2016 said:
So, I've always been confused by this, and I'd appreciate if anyone could help me out! The total increase in cross-sectional area of all capillaries combined decreases the velocity. However, Poiseuille's Law states that flow is directly proportional to pi*r^4. Wouldn't that mean that an increase in cross sectional area increases flow rate? Is there a difference between flow rate and velocity, or am I missing something here? Thanks in advance!
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Flow rate is constant. Flow rate = Area*velocity so increase the area, the velocity will fall to compensate since the flow rate does not change
 
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Oh, SDN, someone always has to get their panties in a bunch over something ridiculous. 🙄
I think we're all old enough here that we know the effects of melatonin and can read the dosage on the lil bottle.
 
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Pusheen said:
Oh, SDN, someone always has to get their panties in a bunch over something ridiculous. 🙄
I think we're all old enough here that we know the effects of melatonin and can read the dosage on the lil bottle.
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HEY. This is serious business. You take too much melatonin and you may not wake up for days (ref: somethin I think I read once).
 
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im having panic attacks thinking that our chem/physics section will be tough like the aamc one and i will just screw up and there goes my 7 hr exam lol
 
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pre.med2016 said:
Thank you! So Poiseuille's Law only applies if we are assuming that there is a change in flow rate?
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Yup so an increase in viscosity = decrease flow rate, decrease the radius = you decrease the flow rate, and flow rate is directly proportional to pressure gradient for poiseuilles law
 
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I was mentioning to my bf that I was going to be super worried about my scores and that the next month would be absolute torture. He suggested I just never look at my scores, apply to all my schools, and just hope for the best. Live in constant oblivion of what my scores were and never know how they affected my chances 🤣
 
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Pusheen said:
I was mentioning to my bf that I was going to be super worried about my scores and that the next month would be absolute torture. He suggested I just never look at my scores, apply to all my schools, and just hope for the best. Live in constant oblivion of what my scores were and never know how they affected my chances 🤣
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I cannot see anyone on SDN being able to accomplish this.
 
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StudyLater said:
I agree it was hard but if I can do relatively the same as I did on that section on everything I'd be beyond grateful.
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yeah i agree. I ended up with an okay score for that section, but after finishing the section I thought i got destroyed. if that happened on the exam, i would lean towards voiding... which i reallllllyyyy dont want
 
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I know this conversation was had a while back, but I can't find it.

What pI's should we know for amino acids? Should I know the pKa's for all the possible groups?
 
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Pusheen said:
I know this conversation was had a while back, but I can't find it.

What pI's should we know for amino acids? Should I know the pKa's for all the possible groups?
Click to expand...
Histidine: 6
Lysine: 10.48
Arginine: 12.54
Aspartic Acid: 3.9
Glutamic Acid: 4.08

Amino NH3+: 9.4
Carboxyl COO-: 2.2
 
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The general consensus is that CARS QP1 is more difficult than the CARS we'll actually see, right? It feels significantly more challenging than the OG and FL from AAMC.
 
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Pusheen said:
Oh, SDN, someone always has to get their panties in a bunch over something ridiculous. 🙄
I think we're all old enough here that we know the effects of melatonin and can read the dosage on the lil bottle.
Click to expand...
😴
fleur64 said:
im having panic attacks thinking that our chem/physics section will be tough like the aamc one and i will just screw up and there goes my 7 hr exam lol
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No god please don't let it be the same lol.
 
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Wouldn't it make more sense to just learn the individual pKa's of the separate parts of the amino acids? (nh3, cooh, oh)? What is the purpose of averaging them into a pI
 
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Pusheen said:
Are those pI's? pI is the average of pKa's right? Lol I feel dumb because this was explained to me before, but I clearly still don't get it
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Those are pk values. So learn those. It's easy to find the pI but it depends on the pH of the solution the AA's are in so its kind of pointless
 
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TexasSurgeon said:
Those are pk values. So learn those. It's easy to find the pI but it depends on the pH of the solution the AA's are in so its kind of pointless
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got it. So I would take into account pKa of side chains, nh3, and cooh, to find the charge of an amino acid at a given pH. If the pH rises above the pKa of the functional group, that functional group gets deprotonated.
 
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Someone want to give me a quick explanation of how to factor in the weight of the meter stick when calculating center of mass? Using this formula

mx+m1x1 +m2x2
----------------------
m+m1+m2
 
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Pusheen said:
got it. So I would take into account pKa of side chains, nh3, and cooh, to find the charge of an amino acid at a given pH. If the pH rises above the pKa of the functional group, that functional group gets deprotonated.
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There you go! Now remember which groups are positive and negative on AAs

And know how to do it in a chain of AA's-- in a chain, you find the region where it's got a 0 charge and take the average of the two pK values adjacent to that region
 
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Pusheen said:
Someone want to give me a quick explanation of how to factor in the weight of the meter stick when calculating center of mass? Using this formula

mx+m1x1 +m2x2
----------------------
m+m1+m2
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I wouldn't do it that way.


Use torques if you can. torque = rl or rFsin(theta)

but the weight of a meter stick would just be the value of its weight and the distance would be it at halfway.

I find the torques easier though.
 
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TexasSurgeon said:
I wouldn't do it that way.


Use torques if you can. torque = rl or rFsin(theta)

but the weight of a meter stick would just be the value of its weight and the distance would be it at halfway.

I find the torques easier though.
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yeah, I understand the torques better, but I've come across problems, where they give you a 1kg stick with mass 1 at 20 cm, mass 2 at 30 cm, mass 3 at 50 cm, ect, and then want you to find the center of mass of the stick. How would I do torques without knowing where the center of mass actually was? I guess I could introduce an x unknown or something but that just seems needlessly complex
 
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does anyone have notes for the addendum for chapter 8 in psych (TPR)
I read it before, but after going through it today, i realized i dont remember ****
 
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clathrin413 said:
The general consensus is that CARS QP1 is more difficult than the CARS we'll actually see, right? It feels significantly more challenging than the OG and FL from AAMC.
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CARS QPack 1 has harder to read passages but the questions are generally more doable. The AAMC now typically goes along the lines of easier to read passages but harder to do questions. For all of you guys having issues with nerves, please don't resort to over the counter sleep aids - as others have said they may have deleterious effects (next day grogginess) or may just not work at all and be a waste of money. (Source: see status).
 
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I really want just one more practice test or even half length from AAMC...I've been drilling my weak areas for the past few weeks and I have no idea if I've improved :scared:
I just got a 91% in bio 1 qpack, but it's so different from the new bio passages, I feel like it's almost irrelevant :scared:
 
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Pusheen said:
I really want just one more practice test or even half length from AAMC...I've been drilling my weak areas for the past few weeks and I have no idea if I've improved :scared:
I just got a 91% in bio 1 qpack, but it's so different from the new bio passages, I feel like it's almost irrelevant :scared:
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It's not as irrelevant as you think. I thought it was irrelevant too, but after finishing the real thing I was glad I did those QPacks. Because at the end of the day as complicated as things can get, those basics will always be the foundation upon which you must base your answers off of -- and if you don't have a good understanding of the basics the more complicated the questions will trick you.
 
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fleur64 said:
yeah i agree. I ended up with an okay score for that section, but after finishing the section I thought i got destroyed. if that happened on the exam, i would lean towards voiding... which i reallllllyyyy dont want
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All that showed me is I will have no sense of how I did whatsoever, and therefore I will not void.
 
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I got a call from my testing center and they told me I need to be there by 6.45. Testing will begin at 7.30. IT'S REALLY HAPPENING.
 
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Pusheen said:
uh, I don't quite get this part..Why would one do this?
Click to expand...

If you have a string of AA's with charged groups in them and they say "Find the pI at a pH of 12" you have to do this.

1. Draw out a line on paper starting with the carboxyl 2.2 pK and label the right side with the max pK value you have in the AA sequence (can be up to 12.48 for arginine)

2. Start from the left and assume the pH to be 1 or something. What is the charge of the peptide at that value? Suppose it's +2. That means you have to deprotonate the AA 2 times to reach a neutral charge of 0

3. At the neutral charge of 0, there should be 2 pK values of AA's on either side of your line. Average those two pK values and that is your pI

Pusheen said:
yeah, I understand the torques better, but I've come across problems, where they give you a 1kg stick with mass 1 at 20 cm, mass 2 at 30 cm, mass 3 at 50 cm, ect, and then want you to find the center of mass of the stick. How would I do torques without knowing where the center of mass actually was? I guess I could introduce an x unknown or something but that just seems needlessly complex
Click to expand...

Ok lemme get back to u
 
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TexasSurgeon said:
If you have a string of AA's with charged groups in them and they say "Find the pI at a pH of 12" you have to do this.

1. Draw out a line on paper starting with the carboxyl 2.2 pK and label the right side with the max pK value you have in the AA sequence (can be up to 12.48 for arginine)

2. Start from the left and assume the pH to be 1 or something. What is the charge of the peptide at that value? Suppose it's +2. That means you have to deprotonate the AA 2 times to reach a neutral charge of 0

3. At the neutral charge of 0, there should be 2 pK values of AA's on either side of your line. Average those two pK values and that is your pI



Ok lemme get back to u
Click to expand...

Thanks!
Don't worry about the torque thing, I'll figure it out before the test 🙂
 
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