APRIL MCATers Club!!!!

[Tweetie_bird]

I believe it's only ascending since that is the place where most of the ions etc are grabbed and pumped out. Remember that the decending loop is mostly permeable to water. In ascending loop, you get pumping out of ions.

Yeap, that's it. Just checked my prep books and that is what it says. go mcaters! I think that collectively, we are all kicking ass! If only the MCAT was a group test.
Tweetie

---

Members don't see this ad.

 

[CoffeeCat]

What about the descending loop of henle? Which does more active transport ascending/descending? (Don't have practice books on hand)

 

[Premed315U]

Thanks Tweetie and everyone.

I love our club )

Okay everyone, come on, post some questions of the day!!!

By the way, has anyone taken an AAMC I yet? I did today, but not sure how to score it, and how it compares to others? Any thoughts, opionins, etc?

 

[Tweetie_bird]

HEHEHE...love the President, who gave birth to it.

Here's an easy one--
Which cells work use antibodies in their immune response?
a. T Cells
b. B Cells
c. Helper T Cells
d. Cytotoxic T cells

And the answer is....

B cells.
Tweetie

 

[Elysium]

I would be so friggin happy if the real MCAT were as friendly as the questions on this forum. I'm getting my ass kicked around in TPR in bio, and that's one of the few sections I have confidence in. I think we all like the bio stuff, so there is a disproportiante amount of questions about it. We got to get to that nasty g-chem and phsyics, which is a hell of a lot harder that physiology (IMHO). Here's another nasty PS
question:

Compared to the atomic radius of Ca, the atomic radius of gallium is:
a) larger, because increased e- charge requires that the same force be distributed over a greater # of e-
b) smaller, because gallium gives up more e-, thereby decreasing its size.
c) larger, because its additional e- increases the atomic volume
d) smaller, because increased nuclear charge causes e- to be held more tightly.

Hint: look at your friend the periodic table

Answer...

D

Good times.

 

[Street Philosopher]

I actually hate the bio section the most... I prefer topics that emphasize concepts over facts. I actually like the verbal section the most because you don't really have anything to study... just practice. <img src="graemlins/laughy.gif" border="0" alt="[Laughy]" />

 

[Elysium]

I totally agree with you schoolboy! It sounds really dorky, but I actually like some of the passages because I learn something new.
I could do VS passages all day long, but I hate that damn physics!!

No offense to physics lovers out there...

 

[Tweetie_bird]

I can AMEN to that!! I actually realized how much I appreciate teh stuff I read in Verbal b/c it's always so applicable. Plus, we always seem to hate the humanities/politics stuff, when it's actually good..b/c now when we talk about politics, we may sound like we KNOW what we are talking about.

Anyway, last night I was watching this movie about the American Revolution and key things that precipitated it, and I recognized a LOT of the stuff in the movie was right out of an MCAT passage! I felt smart that the info to me was actually already known!
Tweetie

 

[DocKwi]

Hey whats up? Yeah I started the Kaplan class this weekend!! Wow..that diagnostic test..whewwwwww...once it was over and we had our break...every single one of us in that class room felT STUPID!!! We got to the physics portiona and a friend of mine raised his hand and said...can i use a CALCULATOR..the Kaplan INstructor said no..and i just laughed!! Oh well..gotta study my butt off b/c I wanna go to Med school!! Well goodluck to everyone out there and feel free to IM me sometime to talk about MCAT or medschoool or whatever!! Keep it real..and I fould that playing Rocky's theme song Eye of the Tiger gets you pumped up!! Haha!! IM me ncstatekwi...later all

 

[bentz]

let me just say that whoever came up with this idea, this a great idea. Is it just me, I think there are mostly only biological questions. Guys you need to post more physical questions. keep'em coming!!

 

[medical22]

I am having a very hard time memorizing all the reactions and reagents for organic chem. I did very well in my class but that's because we had a test on 3-4 chapters at a time. Any suggestions as to how I should study all the reactions?

 

[CoffeeCat]

How many people are taking a course and how many are studying on their own?

 

[CoffeeCat]

Select the endocrine gland that is incorrectly paired with its hormone product:

A. Adrenal cortex-cortisol
B. Adrenal medulla-aldosterone
C. Adrenal medulla-epinephrine
D. Adrenal cortex-mineralocorticoids

And the answer is...


B!

 

[Premed315U]

Has anyone thought of good mneumonics to remember physiology details? Please post any and all that you think of.

Here's one that might help people that I just thought of:

during embryonic development, what gives rise to the brain? Anterior section so AB ABrain

what gives rise to the spine? PS Poster Spine


and question of the day!
In which of the following solvents are alkenes the most soluble?
a) water
b) ethyl alchol
c) carbon tetrachloride
d) ammonia


and the answer is..


c

 

[Premed315U]

Come on everyone, post a question!

Here's another question

Where does rust form?
Where does Fe2+ form?

and the answer is


rust forms at cathode
Fe2+ forms at the anode

 

[Premed315U]

Come on everyone. I'm the only one posting!!! Give me some questions

 

[bentz]

here a question for you:

The sequence of amino acids along a peptide chain determines its:
a-primary structure
b-secondary structure
c-tertiary structure
d-quaternary structure

the answer is:
A

 

[bentz]

here an another one:

When a racemic mixture is separated by chemical meams it leads to:
a-loss of optical activity
b-isolation of enantiomers
c-racemization
d-isolation of diastereomers

and...

the answer is
B

 

[Cerberus]

An easy one

The "zipper" which hooks sister chromatids together and facillitates crossing over?
a. Chiasmata
b. synaptonemal complex
c. heteroduplex
d. zoetrope

and the answer is............b

 

[Elysium]

OK ya'll, here is a physics teaser:

(acutally, I'm trying to learn electric potential and potential difference and I'm having a major brain block)

1) To recharge a 12-V battry, a battery charger must move 3.6x10^5 of charge from the neg. terminal to the pos terminal. How much work is done by the battery charger? Post in Joules.

2) Calculate the speed of a proton that is accelerated from rest through a potential difference of 120V. Calculate the speed of an e- under the same conditions.

Come on Pre-med315, you know you're itching to do some physics!

Any takers?

 

[bentz]

This is my last question of the day:

How many chiral center exist in
2 methylcyclohexanone

a-0
b-1
c-2
d-3


the answer is

B

 

[Premed315U]

Yay everyone

Here's another!

Which of the following would most likely experience the greatest force of air resistance if dropped from an airplane?
a) feather
b) elephant
c) bullet
d) toaster


b: air resistance depends on surface area, not mass

 

[Premed315U]

Here's another
Which of hte following is true if m1 has a mass of 1 thousand times greater than the mass of m2?

a) the force on m1 will be 1000X greater than the force on m2
b) the force on m2 will be 1000X greater than the force on m1
c) the force on m1 will be equal to the force on m2 and will not be zero
d) the net force on both objects will be zero

the answer is..

c
because the forces are equal and opposite

 

[bentz]

what formula do u use to solve this problem. Is it F=ma. can u explain the answer please?

 

[Premed315U]

Are you referring to the equal and opposite?

It's Newton's 3rd law that all forces are equal and opposite. Let me know if you mean a different question

 

[bentz]

yep I was talking about the equal and opposite question. I did not get it the way you worded the question. it's kind of make sense now

 

[Premed315U]

I think it's basically just knowing Newton's 3rd law and applying it

 

[Tweetie_bird]

Originally posted by bentz:
•here an another one:

When a racemic mixture is separated by chemical meams it leads to:
a-loss of optical activity
b-isolation of enantiomers
c-racemization
d-isolation of diastereomers

and...

the answer is
B•••

Wait, no, I refute this one. Where did you get this from? This is a standard error most students make when they talk about chemical separations....upon separating enantiomers thorugh chemical means, you DO NOT get enantiomers initially....first, you get the salt of one of those enantiomers, AND it's DIASTEREOMER.

The diastereomers are separated b/c of different chemical properties....THEN, acidified, and upon acidification, you get two separate enantiomers.

I know I am right on this one. (pretty sure...)

Tweetie

 

[Tweetie_bird]

Originally posted by Premed315U:
•Here's another
Which of hte following is true if m1 has a mass of 1 thousand times greater than the mass of m2?

a) the force on m1 will be 1000X greater than the force on m2
b) the force on m2 will be 1000X greater than the force on m1
c) the force on m1 will be equal to the force on m2 and will not be zero
d) the net force on both objects will be zero

the answer is..

c
because the forces are equal and opposite•••

Here's my take on this....
I believe the answer would have been A b/c force is dependant on mass, HOWEVER, according to the answer, "C" that they gave, I believe the two masses were in contact with one another..next to each other or one on top of another. The ONLY way you can have "equal and opposite" forces is if two masses are in contact...Premed, did you happen to not include a picture (or atleast mention it) in your question when there should have been one? I don't see how the answer can be "C" otherwise....
Tweetie

 

[Premed315U]

Hi Tweetie, there's no diagram. I'm pretty sure it's C because it's from Examkrackers 1001 Physics, which supposedly has no mistakes, let's hope. The authors seem very thorough

 

[bentz]

This was not my own question. But I still believe my answer is right for the racemic question because I just a read small section on separation of a racemic mixture. It depends on the other reactant. if the reactant is achiral, you get enantiomers mixture. But if the other reactant is a chiral molecule, you will get diastereomers mixture. I will do more reading on this and get back to you when I am fully awake. in the mean while, keep me inform!!!

 

[bentz]

c u guys tomorrow i gotta go to bed now. I will wake up early tomorrow!!!

 

[Tweetie_bird]

oh well, perhaps I am wrong. I will check my MCAT books and let you know.

For now, I wanted to inform all of you that we are holding chat sessions each week at specific hours. Here is a copy of what i wrote in another forum, for you guys to read. Hopefully y'all can make it.

-------------------
Alright,
So concensus says Friday and Saturday nights it is, atleast for this week. IF you feel like these days are bad, we can change the days once we have enough complaints that those days don't work out.

One session planned this week:
THIS FRIDAY, Feb 1st--6 p.m. WEST COAST TIME which is 9 p.m. EAST COAST TIME. (tell me if this works!)


Next Session: following MOnday. Hours to be determined. East coast people, how LATE would you be willing to start our chats, since you guys are 3 hours ahead of us? PLEASE ANSWER!

Lastly, I am taking the initiative and makin a call on what we will discuss this Friday. I would like to start with Gen Chem.
Topics included:
Quantum numbers; Electronic configuration; Periodic Chart Trends; Bonding Types; Molecular Geometry (trigonal planar etc); Chemical Kinetics (rate laws; orders of reaction etc); Thermodynamics (Delta G, H, S, Temp; Ksp products; and Phase changes/Phase equilibria (ice melting to liquid to boilin to gas etc).

Ok, this is A LOT..but, we don't have to do it all in one day. Chat session may last b/w 1-2 hours. STUDY YOUR ASSES OFF! I don't want to sound like a drill sergent but, PLEASE, don't come to the chat session if you don't know simple things like "What's Delta G?" It will just make our time efficient. Thanks!

Tweetie

 

[Premed315U]

Tweetie,

could you please post the transcript from each chat session for those of us who can't make it?

Thanks!!

 

[medical22]

Originally posted by medical22:
•I am having a very hard time memorizing all the reactions and reagents for organic chem. I did very well in my class but that's because we had a test on 3-4 chapters at a time. Any suggestions as to how I should study all the reactions?•••

Any suggestions???

 

[Tweetie_bird]

I have taught O. Chem before, and my best advice is to focus on the BIG PICTURE, not on the small reactions. KNOW why Acyl chlorides are usually more reactive than exters or amides..know why a certain carbonyls is more acidic than others, know the FUNCTIONALITY of each group and IN GENERAL how it reacts with other groups with differennt functionalities.

For example, an Acetoacyl chloride
CH3C(O)Cl is going to react with an NH3. WHY? Carbon in carbonyl looks mighty sexy to the electrons on the N in NH3. Why again? B/c the C=O bond is polar, and Carbon has a partial positive charge..therefore, the N will attack the Carbonyl. Now, what happens? The double bond with "O" becomes a single bond. Why? B/c if it didn't carbon would have MORE than 8 electrons (which is a no no)...now, you have a transition state--Singly bonded Oxygen with it's negative charge, and the Amino group with it's positive charge. What happens next? That Oxygen is so moody with the negative charge, that it wants to make the double bond occur again, how does it do that? It attacks the Carbon again, the Chlorine leaves b/c that is the best leaving group in the entire molecule. Why is the Amine not leaving? Well? It's certainly not b/c "it was the reactant, can't be part of products"....it doesn't leave b/c it is MORE BASIC than Chlorine, and less happy in general being on it's own in the presence of an acid. The Chlorine on the other hand, is a 'weaker' nucleophine than NH3 and will happily take the status of the leaving group.

If you had such a story for the biggies, you would see a BIG PICTURE..that is inherent to all reactions of that particular type. For example, ALL acyl halides have the halide as the leaving group. ALL Carbonyl carbons LUUUUVE being attacked b/c they are so damn positive...all Amines love attacking b/c of those electrons on the Nitrogen. Does this help at all?

Thanks!
Tweetie

 

[Tweetie_bird]

Originally posted by Premed315U:
•Tweetie,

could you please post the transcript from each chat session for those of us who can't make it?

Thanks!!•••

ummm, sure. But first people need to say YES to coming...or the only person in the chat script will be yours truly.

Tweetie

 

[laavp]

Is anyone who is taking Kaplan for the MCATS tried their topical tests?? Does anyone find them difficult? I tried two from the physics section and thought it was INCREDIBLY difficult! I almost cried when I saw my scores! I would like to know others experiences. Thanks

 

[Premed315U]

Laavp, please post some of the questions here for everyone. We're creating a database of MCAT questions

 

[Tweetie_bird]

yes, I have tried them and they are unbelievably hard. I dont think the MCAt questions will be like this, but the more you practise this kind of stuff the better it will be for you.
My best suggestion is to do it every two weeks or so, and see improvements. It worked for me, albeit not by much.

Why am I seeing no activity on this thread today?!?
Tweetie

 

[Optimistic]

Okay guys here is my question of the day.
Which of the following is not a function of bile:
A Emulsification of fats to minute particles...
B Neutalization of acid emptied into the large intestine from stomach.
C Transport of end products of fat digestion through the intestinal mucosal membrane.
D Excretion of bilirubin ,the end product of hemoglobin destruction.
Fairly easy ... right?

I will post the answer later on.

 

[Tweetie_bird]

ok, this one is actually tough for me. it's either B or D, but I am leaning toward D b/c I have never heard of bile helping in excretion of end products of anything except FATS...

Then again, B could be right. I thought all the chyme was neutralized in the small intestine...not large intestine. right?
What's the answer please?
Tweetie

 

[Elysium]

What a tease! You gotta post the answer!

For all of who have been doing verbal practice:

I took one of the TPR practice verbal tests tonight (timed) and got 12 wrong. WHere does that put me? It's so crappy, because you have no idea of what the score is...or could be. How are ya'll doing in VS?

 

[buglady]

Originally posted by Optimistic:
•Okay guys here is my question of the day.
Which of the following is not a function of bile:
A Emulsification of fats to minute particles...
B Neutalization of acid emptied into the large intestine from stomach.
C Transport of end products of fat digestion through the intestinal mucosal membrane.
D Excretion of bilirubin ,the end product of hemoglobin destruction.
Fairly easy ... right?

I will post the answer later on.•••

Is this a Kaplan question? Just curious. The answer is B. The acid bile neutralizes isn't dumped into the large intestine, but into the small intestine (duodenum). It's not D, 'cuz bilirubin is a bile pigment.

 

[Jameson]

It's B. The acid is neutralized in the SMALL intestine after it combines with bile and pancreatic juice(alkaline). No way does the stomach empty into the LARGE intestine, which is what I think the O.P. wrote in the question. Any other takers?

 

[buglady]

Here's my question of the day/night:

The role played by tropomyosin is skeletal muscle contraction is most similar to that of:

a. an inducer
b. an immunoglobulin
c. a repressor
d. a catalyst

And the answer is......

C!

 

[Optimistic]

Originally posted by TEDillard03:
•What a tease! You gotta post the answer!

•••
Sorry guys ,I didnt mean to delay posting the answer for this long. But you all are smart and got the answer right.answer is B. Acid get neutralized in the small intestine.

 

[Optimistic]

okay here is another one( from Examkrackers) ,easy for everybody else and impossible for me because Iam intimidated by vectors.
A man entered a cave and walked 100m north. He then made a sharp turn 150 degrees to the west and walked 87m straight ahead .How far is man from where he entered the cave?
A 25m
B 50m
C100m
D150m

Answer is B . Can some body explain how? <img src="confused.gif" border="0">

 

[Premed315U]

Optimistic, I'm confused about this one, uh oh

Here's one for everyone
If the density of a gas is given as P, which fo the following expressions represents the molecular weight of the gas?
a)Pressure/PRT
b) PRT/Pressure
c) nRT/PressurexP
d)PressurexP/RT

and the answer is

B

 

[Atlas]

Hey folks! Great post you have going here. I'd like to direct your attention to my post regarding the MCAT Embyo crash course. Do any of you have input regarding what to study and what not to study with respect to the Embryo stuff? I'm reading KAPLAN's (big) book and it does a nice job of simplifying things, but can anyone tell me, from their own experiences with the 'CAT, what kind of Embryo stuff should I focus on?

Peace