TBR CBT 6 BS Question #112...individual AA structure/properties?

[MedChallenge]

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Are we going to be required to know things like this below for each amino acid? I was under the assumption that these specifics wouldn't be tested on the MCAT.

112. Which of these statements about the amino acid threonine must be true? I. It is water-soluble.
II. It contains two chiral centers.
III. It is hydrophobic.

A. I only
B. I and II only
B is the best answer. Threonine has a side chain of -CH(OH)CH3. The side chain has a chiral center, resulting in two chiral centers on threonine. The hydrogen-bonding of the hydroxyl group makes threonine highly water-soluble, and therefore hydrophilic, not hydrophobic. This makes statements I and II true, but statement III false. The best answer is B.
C. I and III only
D. I, II, and III

 

[Rabolisk]

Hmm. Was this a discrete? You certainly won't have to know this for the MCAT, although you can eliminate C and D without knowing anything about threonine.

 

[MedChallenge]

Hmm. Was this a discrete? You certainly won't have to know this for the MCAT, although you can eliminate C and D without knowing anything about threonine.

It was a discrete. Yeah, I eliminated both C and D, but chose A as a complete guess.

So from your "hmm" I'm hoping your understanding was the same as mine. 👍 Whew! lol