BR says I need to MEMORIZE every pKa value for every Amino acid?

[buccsmf1]

I planned on memorizing structures and which are polar/non-polar etc.... but BR claims "for the MCAT you should recognize the twenty amino acids for which we code, along with general pKa data for the amino terminal, carboxyl terminal, and the side chain of protic amino acids"

It seems like on each passage they include some random isoelectric questions that requries you to have memorized every pKa value for every AA..... and i keep missing every one

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[Wheee]

that's weird. I really doubt you need to memorize any pKa's, just recognize which terminus gets deprotonated or protonated at certain pH. I don't think you need to know structure either, besides knowing which have sulfur for disulfide bridges.

I don't remember having any questions about picky details on a.a. on my test. Maybe one (or maybe it was a practice AAMC), but the other options were clearly wrong, so picking was easy.

 

[engineeredout]

I've never seen anything requiring that much knowledge on the MCAT/practices. Structures are unnecessary, hell even knowing the amino acids is probably unnecessary.

 

[Segovia]

I planned on memorizing structures and which are polar/non-polar etc.... but BR claims "for the MCAT you should recognize the twenty amino acids for which we code, along with general pKa data for the amino terminal, carboxyl terminal, and the side chain of protic amino acids"

It seems like on each passage they include some random isoelectric questions that requries you to have memorized every pKa value for every AA..... and i keep missing every one

Along with general pKa data. On one of the AAMCs I took there was a question that definitely wanted you to know when deprotonation would occur (they provided pKa info).

I would just be aware of ballpark figures for C/N terminus and know which protons will fly off first as pH is increased, and what the amino would look like at a given pH.

 

[Red Leader]

Also it says only the protic amino acids. That's hardly all of them.

BTW this knowledge will probably be worth only 1 point on the real exam if that lol.

 

[partinerns]

Just know that aspartate and glutamate are acidic, and that arginine, lysine, and histidine are basic and be able to explain why. Everything else will be more or less neutral and the above info will be enough to get you by on any question.

 

[DrDre2001]

Along with general pKa data. On one of the AAMCs I took there was a question that definitely wanted you to know when deprotonation would occur (they provided pKa info).

I would just be aware of ballpark figures for C/N terminus and know which protons will fly off first as pH is increased, and what the amino would look like at a given pH.

I agree with this. The keyword in that Berkely Review quote was general

 

[ldnk]

I'll save you a lot of time by saying, don't do it.

Then I will make you waste some time by saying, read the passage again because it probably didn't tell you to memorize everything. The MCAT DOES NOT TEST SPECIFIC VALUES.

 

[matth87]

When ph < pKa the group will be protenated
When ph > pKa the group will be deprotenated

-NH2 amino terminus are about 9/10 pka
-COOH ends are about 2pka

 

[Parthenon89]

i think the most useful information to 'memorize' is to know the 3 basic amino acids, and the 2 acidic ones, also know the smallest amino acid (glycine) and the only one that forms a covalent (disulfide) bond which is cysteine.

EK Bio taught me, so far its been tremendously useful.

 

[monomania]

That's nonsense. At most, I would just know the acidic/basic amino acids, and possibly also have an idea of which ones are polar/nonpolar. Also, know the pKas of the amino and carboxy terminal (~9 and ~2) as mentioned above.