Which four of the following statements about amino acids are true? (a) Proline has an overall charge at physiological
pH(7.4).
(b) Thr and Ser are polar amino acids.
(c) Lysine has one stereocenter (chiral center).
(d) The form of glycine used by the human body is D -glycine.
(e) The Ala side chain does not form hydrogen bonds with other amino acids.
(f) Methionine is a thiol.
(g) Phe can undergo oxidation to form Tyr.

• Phe can undergo oxidation to form Tyr.

• The Ala side chain does not form hydrogen bonds with other amino acids.

• Thr and Ser are polar amino acids.

• Lysine has one stereocenter (chiral center).

Explanation:

Amino acids are simply organic compounds which are known to contain carboxyl and amine functional groups and the main elements that are found in an amino acid are oxygen, carbon, hydrogen, and nitrogen.

The true statements about amino acids are:

• Phe can undergo oxidation to form Tyr.

• The Ala side chain does not form hydrogen bonds with other amino acids.

• Thr and Ser are polar amino acids.

• Lysine has one stereocenter (chiral center).

It should be noted that Methionine is not a thiol but rather a thio ether. Also, proline is simply a neutral amino acid and the statement that proline has an overall charge at physiological

pH(7.4) is false.

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explanation:  

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