Tryosine & Methionine Amino Acid Structure! - USMLE Forums
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Old 08-18-2013
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Biochemistry Tryosine & Methionine Amino Acid Structure!

Hi,
I'm studying amino acids now and I found in Kaplan that Methionine has uncharged polar side chain while tryosine is non-polar hydrophobic,
then I saw it reversed in Lipincott, which one I should believe now ??!!
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Old 08-18-2013
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I had the same problem, even posted the same issue. But, both Kaplan and Falcon say Met rather than Tyr as part of polar uncharged group. I guess the aromatic ring of tyrosine is more hydrophobic despite the hydroxyl group it contains, whereas Met is aliphatic containing sulfur. I went with Met being part of the uncharged polar group and tyr part of the hydrophobic group.
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Old 08-18-2013
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Quote:
Originally Posted by Mo-tongji View Post
I had the same problem, even posted the same issue. But, both Kaplan and Falcon say Met rather than Tyr as part of polar uncharged group. I guess the aromatic ring of tyrosine is more hydrophobic despite the hydroxyl group it contains, whereas Met is aliphatic containing sulfur. I went with Met being part of the uncharged polar group and tyr part of the hydrophobic group.
If there is no definitive answer, I'd go with Lipincott as OH- will make tyrosine polar.
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