juniper456

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do we have to? i.e., which ones are hydrophobic, hydrophilic, acidic, basic, etc. . .
 

clkimmey

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juniper456 said:
do we have to? i.e., which ones are hydrophobic, hydrophilic, acidic, basic, etc. . .
didn't you already have to do that for biology?

you might as well know it. you're going to be expected to know it in med school anyway.

and yes, there may be a question or two on the MCAT that pertain to amino acid characteristics.
 

UCLAstudent

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It can't hurt. I got a question about which AA is achiral.
 
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clkimmey

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UCLAstudent said:
It can't hurt. I got a question about which AA is achiral.
glycine

(right?) :confused:
 
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juniper456

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clkimmey said:
glycine

(right?) :confused:
yes-- glycine is achiral. if i know this off the top of my head, do i know enough??
 

UCLAstudent

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Yes, it's glycine. :D Juniper, you definitely don't need to know the structures of all of the side chains. It can't hurt to be able to categorize the different amino acids. By categorize, I don't mean that you have to be able to recite which amino acids are polar uncharged or hydrophobic, but I would be familiar enough to distinguish which amino acid is the "odd one," given four answer choices. And, be sure to know the biological implications of histidine due to its near-physiological pka. Hope this helps! :)
 
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juniper456

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UCLAstudent said:
Yes, it's glycine. :D Juniper, you definitely don't need to know the structures of all of the side chains. It can't hurt to be able to categorize the different amino acids. By categorize, I don't mean that you have to be able to recite which amino acids are polar uncharged or hydrophobic, but I would be familiar enough to distinguish which amino acid is the "odd one," given four answer choices. And, be sure to know the biological implications of histidine due to its near-physiological pka. Hope this helps! :)
"His goes both ways. . ." heee heeeee

anyway, what IS the biological implications of this? conformational changes? :confused:
 

UCLAstudent

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Well, since histidine's pka is ~6, it can easily exist in the protonated or deprotonated form at physiological pH. As a result, Histidine tends to be found in enzyme active sites, where it can act as either a proton donor or a proton acceptor to catalyze biological reactions. Also (this is just an example, you don't need to know this for the MCAT), histidine plays a big role in hemoglobin. When histidine is protonated, it is positively charged and can form ionic interactions with negatively charged amino acid side chains. These ionic interactions help to stabilize the T-state of hemoglobin (the form with low oxygen affinity). I digress. :D
 

UCLAstudent

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One last thing (a mnemonic): "His Lys Arg basic" (his lies are basic). ;)
 

UCLAstudent

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I do have lots of mnemonics, but they were mostly for memorizing the one-letter designations for the amino acids (which you do not need to know).

W = tryptophan = tWo rings
Q = glutamine = Qtamine ("cute-amine")
R = arginine = Arrrrrrrrrginine
V = valine (side chain is shaped like a V)
F = phenylalanine = Fenylalanine

As you can see, these won't be terribly useful for the MCAT. :D I will get back to you if I remember something more useful.
 

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Just take a biochem class, they'll make you learn all the AA. It's good for you =P
 

GreekPre-Med

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I took a basic biochemistry course. We had to be able to tell which amino acids were basic, hydrophilic, etc. by the structure but we did not have to memorize the structures. They were provided for us. Is it necessary to MEMORIZE THE STRUCTURES or just be able to tell which ones were achiral, etc.? DId the question stem include the structure of the amino acid? Thanks
 
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UCLAstudent

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GreekPre-Med, the question stem did not include the structure of the amino acid. But, glycine is the only achiral amino acid. It is an exception.
 

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i dont think we have to know the exact structures, but u should know which ones are basic, acidic, polar, non-polar, achiral, and can form S-S bonds.

and also how it moves during electrophoresis using its isoelectric point.
 

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EK had a cool neumonic but I forgot it... UCLAStudent, you got into UCLA SOM? I hope so!!! If so, CONGRATS!!!!! :clap: :clap: :thumbup: Let me know when you see me on AIM! I'll tell you another thing, YOU REALLY DESERVE IT. :)
 

psiyung

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UCLAstudent said:
I do have lots of mnemonics, but they were mostly for memorizing the one-letter designations for the amino acids (which you do not need to know).

W = tryptophan = tWo rings
Q = glutamine = Qtamine ("cute-amine")
R = arginine = Arrrrrrrrrginine
V = valine (side chain is shaped like a V)
F = phenylalanine = Fenylalanine

As you can see, these won't be terribly useful for the MCAT. :D I will get back to you if I remember something more useful.
:laugh: :laugh: :laugh:
 

stoleyerscrubz

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Anything else to know beyond what EK goes over on amino acids? Ek devotes one paragraph to this and just classifies them by basic,acid,polar, and nonpolar.

Juniper, how did you know which was achrial and about Histidine? I don't remember Prof Alaie going over that. I must've been busy writing notes 100mph. :eek:
 
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juniper456

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stoleyerscrubz said:
Anything else to know beyond what EK goes over on amino acids? Ek devotes one paragraph to this and just classifies them by basic,acid,polar, and nonpolar.

Juniper, how did you know which was achrial and about Histidine? I don't remember Prof Alaie going over that. I must've been busy writing notes 100mph. :eek:
i read about them in my princeton review book. . .
 

myodana

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juniper456 said:
do we have to? i.e., which ones are hydrophobic, hydrophilic, acidic, basic, etc. . .
you don't have to memorize structures. in fact, you really shouldn't waste your time memorizing when you could be using that time to do something mroe important. however, you should know a few key ones... i'm sure it tells you this in whatever book you're working with. also you should know trivia (i.e. glycine is achiral), and general classifications... acidic, basic, etc.
 

stoleyerscrubz

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HKR?
ED?
what?

Cozmosis said:
Since I know them from Biochem, my mnemonic:

Hydrophobic: F VLIP WAM
Basic: HKR Acidic: ED
Together they are: HK RED

Don't ask...
 
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