Remembering Amino Acids?

[jammin06]

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Hey,
does anyone have an easy method (relatively speaking) to remember the characteristics of the amino acids (whcih are polar, nonpolar, acidic, etc..)? As of now, i guess my only hope is to sit down and memorize them, but i figured I would ask in case anyone has a study method that helped them out in the past. Thanks all.

 

[freesolo]

EK said not to memorize them, so i'm not =)

 

[LiNk]

from ek:
basic aa "HAL"
histidine, arginine, lysine
i think that's right 😕

 

[alexisd]

What is EK? I just recently got serious about my MCATs. I am behind and need as much help as I can get.

 

[jammin06]

yea, i'm using the EK set as well, and actually that was the reason why i asked the question. I was taking the 1st 30-minute exam for biology and one of the questions (#7 i believe) basically asked whether you knew that a particualr enzyme (somethign isomerase) would lower the activation energy for the formation of amino acid A or amino acid B. The explination in the back says that the question is on the brink of mcat testing material, but it's information that we would know about the amino acids anyway.

*edit* EK = examkrackers

 

[MoosePilot]

I needed to know one of the aminio acids on the real thing. I think it was a question about which one of the following amino acids would be on the inside of a pore protein. It was just a hydrophilicity question, really.

I also needed some hormones.

I had memorized both for the test.

 

[freesolo]

In the 4th edition of EK bio it says you dont have to memorize the structures of each amino acid, but just recognize the basic structure of a generic amino acid. So why is everyone memorizing htem =/, dont tell me Ek is leading me the wrong way =o.

 

[imsotired]

yea, i'm using the EK set as well, and actually that was the reason why i asked the question. I was taking the 1st 30-minute exam for biology and one of the questions (#7 i believe) basically asked whether you knew that a particualr enzyme (somethign isomerase) would lower the activation energy for the formation of amino acid A or amino acid B. The explination in the back says that the question is on the brink of mcat testing material, but it's information that we would know about the amino acids anyway.

*edit* EK = examkrackers

On that question, you needed to know that you were considering disulfide bonds which would mean that you should have automatically assumed cysteine. Cysteine is the ONLY amino acid that can make disulfide bonds. Memorizing amino acids might help but it isn't necessary. What might help is if you know SOME of the characteristics of amino acids (like proline doesn't conform to an alpha helix configuration due to its ring structure). Of course, if you've taken biochemistry before, then you would know the amino acids by heart. 😀

 

[Noeljan]

ok I am weird but here are a few of my own memory tricks with those amino acids:
well first rem glycine as the baby, non chiral, has a H sidechain. Just rem this one first then go from there...Try to build up in size from there
then alanine is little so it has one methyl group
Valine (think V for valentines day: so when I would draw it out I would draw the propyl group as a C with the two methyl groups attached to make a V)
Then leucine adds an extra CH2 group think L for love
isoleucine is an isomer of leucine
Then:
just remember that phenylalanine and tryptophan have benzene rings attached(or phenyl groups)
proline I thought of puppy🙂 haha bc the structure looks like a dog house (think cycloPentyl)
Serine has an OH (I thought of SERving alcohol)
Threonine serves THree drinks (bc the OH is attached to a center C which is attached to an H and a methly) trust me if you write out the stxs this makes more sense
Tyrosine has a phenol group (benzene with OH attached) no trick for this one, I just memorized
To distingush asparagine from glutamine I thought of asparagine as Sparing a CH2 group (so it has one less that GLN)
Then just replace the amino groups with OH to make the acids (aspartic and glutamic)
Oh for arginine I think I rem winning an argument is positive, hahaha so positive I believe
and always rem histidine with that titratable sidechain at pka 7 I believe but let me double check that one
Ok if I rem anything else I will let you know, I took biochem in the spring and have not yet brushed up on it so I could be missing something
J.

 

[willthatsall]

If you don't have them memorized you aren't very cool.

 

[fonzy]

Is it necessary to memorize anything at all for the MCAT? Is MCAT not a test of reasoning that requires familiarity with and basic understanding of the subject matter?

 

[imsotired]

Is it necessary to memorize anything at all for the MCAT? Is MCAT not a test of reasoning that requires familiarity with and basic understanding of the subject matter?

Maybe for you but not for us....

 

[MoosePilot]

Is it necessary to memorize anything at all for the MCAT? Is MCAT not a test of reasoning that requires familiarity with and basic understanding of the subject matter?

Yes, memorization is required. You don't neccessarily know what you have to have memorized, so to be safe you end up memorizing more than needed.

I memorized a bunch of physics formulas, constants, amino acids, strong acids, strong bases, etc. I didn't use most of them, but I did use enough that I don't feel bad about the extra work.

 

[N-toxicologist]

I also needed some hormones.

I have enough for both of us!

OP: If you're going to memorize anything about amino acids (and you shouldn't), remember which are hydrophobic vs. -philic; which have side groups that re (-) charged vs. (+) charged, and perhaps which have bulky side groups. Anything else should be in the passage. I've seen very little biochem on the MCAT, except for very basic stuff. 👍

 

[amy73]

Ek says not to remember the amino acids in the book. But they turn around and ask tough questions about it in the 1001 book. I think that are trying to tell us to memorize them? or just recognise the gly and the cystine etc?
Any opinions?

 

[HawkeyeBFP]

I've never understood this either. If you look at the AAMC site and the list of MCAT possible subjects, you will not find amino acids among them.

And yet how exactly are you supposed to know, for example, that "cysteine is the only amino acid that can form disulfide bonds" if you DON'T memorize them?

I never needed to know the characteristics of any amino acid until I took biochemistry (where we memorized them all, and it's not that hard and there's only 20 of them and you'll need them later, so you might as well). Biochemistry is not a common prerequisite and I've never met anyone who had to learn them all in biology or chemistry class.

So why does the MCAT use them as subject matter? It's very odd.

FWIW, I don't recall any questions specifically on my version of the MCAT. However, there were some in the practice material (and I used mostly the AAMC tests for practice so I assume they were in there).

 

[velo]

Is it necessary to memorize anything at all for the MCAT? Is MCAT not a test of reasoning that requires familiarity with and basic understanding of the subject matter?

In general that's true, but some memorization is required. People tend to memorize more than they need to, but you can't have a "basic understanding of the subject matter" without committing some things to memory. Know hydrophobic/phillic AAs, know acidic AAs (these will be the ones that end in "acid"), know basic AAs (HAL), and remember that cystine forms disulfide bonds...just remember the other AAs as nonpolar/hydrophobic

 

[CJMPre-Med]

And yet how exactly are you supposed to know, for example, that "cysteine is the only amino acid that can form disulfide bonds" if you DON'T memorize them?

Well, for that particular example, it's because that is a recurring theme throughout most cell/molecular bio courses; you'll definitely see it mentioned a lot. So when you hear disulfide bonds (a feature of tertiary structure which provides stability primarily for extracellular proteins), think cysteine. 😉 😛

 

[MoosePilot]

I have enough for both of us!

LOL!



You don't have to memorize them all, but I would definitely at least know what UNTlabrat mentions. Someone mentioned cysteine (a point if you tell me what makes cysteine into cystine). There are a couple of pretty unique amino acids like that, it might be nice to know why their unusual, because that makes them good questions.

 

[velo]

Someone mentioned cysteine (a point if you tell me what makes cysteine into cystine).

hmm...well a bad speller would probably make cysteine into cystine (half point!!!) 😀

 

[N-toxicologist]

Someone mentioned cysteine (a point if you tell me what makes cysteine into cystine).

2 Cysteine residues undergoing an oxidation reaction to form 1 Cystine by way of a disulfide linkage. 👍 😉

R-S-H + R-S-H >> R-S-S-R + (2 H+) + 2e

I'll take that point--add it to my physical sciences score, please! 😀

 

[HollyJ]

I really wouldn't bother memorizing them. It's a good idea to have a vague notion of the characteristics of some of the more unusual acids (glycine, cysteine, proline, maybe methionine), but even these are pretty optional.

Yeah, you might get a question, but if you do at all, it's going to be one single question, so it's not really worth the effort. Use the time to work on something that's higher yield.

 

[HawkeyeBFP]

Well, for that particular example, it's because that is a recurring theme throughout most cell/molecular bio courses; you'll definitely see it mentioned a lot. So when you hear disulfide bonds (a feature of tertiary structure which provides stability primarily for extracellular proteins), think cysteine. 😉 😛

Well, yes, I do know that, weisenheimer. 🙄

What I mean is, how are you supposed to know that cysteine has a terminal thiol group which can participate in disulfide bonds (thus providing stability, etc. etc.) UNLESS you've memorized the amino acids in the first place?

I mean, they would have to give you cysteine's structure, unless they are implicitly assuming that you know the structures of all of them.

I teach the MCAT, and every time this section comes up I wind up giving a fifteen-minute impromptu lecture on biochemistry because unless I do, almost no one in the class understands the "review" material. I really do wonder about how it is they can put this material on the test.

 

[imsotired]

Bottom line: DON'T MEMORIZE STRUCTURES 😀

 

[CJMPre-Med]

Well, yes, I do know that, weisenheimer. 🙄

Haha, I thought that I was the only person who used the word "weisenheimer". 😀 Sorry, didn't mean to come off that way. 🙂

 

[MoosePilot]

2 Cysteine residues undergoing an oxidation reaction to form 1 Cystine by way of a disulfide linkage. 👍 😉

R-S-H + R-S-H >> R-S-S-R + (2 H+) + 2e

I'll take that point--add it to my physical sciences score, please! 😀

*POOF*

Check back with me middle to late October. Satisfaction (not) guaranteed 😀

 

[RayhanS1282]

IMO, the important things that u need to know about AA's are:
1) generic structure - NH2-CHR-COOH
2) the R is the side chain and is the cause of variation
3) all AA's are chiral save for glycine which has a H as the side chain
4) Zwitter ion - what is it? recogniz it.
5) + and - of the NH2 AND COOH, occurs under what conditions
6) isoelectic point

Personally, I think that memorizing the AA's are time spent doing something else, granted that one or two questions might show up that requires direct knowledge but at this stage of the game, time should be spent brushing up on the major stuff insted of the nuances.

The abovementioned opinions are only my opinions, SDN does not share, agree or endorse these opinions. However, if one should disagree please forward all angry threats c/o SDN to my PM.