BIOLOGY
AMINO ACIDS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Amino acid molecules with a negative charge on the amine group in the form of COO-and a positive charge on the carboxylic acid group in the form of NH3+
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Amino acid molecules with a positive charge on the amine group in the form of NH3+ and a negative charge on the carboxylic acid group in the form of COO-
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Amino acid molecules with a negative charge on the amine group in the form of NH3-and a positive charge on the carboxylic acid group in the form of COO+
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None of the above
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Detailed explanation-1: -A zwitterion is a functional group molecule in which at least one has a positive electrical charge and one a negative electrical charge. The whole molecule’s net charge is negative. The best-known examples of Zwitterions are amino acids. They have a group of amines (basic) and a group of carboxyls (acidic).
Detailed explanation-2: -When an amino acid contains both a plus and a minus charge in the “backbone", it is called a zwitterion and has an overall neutral charge. The zwitterion of an amino acid exists at a pH equal to the isoelectric point.
Detailed explanation-3: -Charge of the amino acid side chains At pH=7, two are negative charged: aspartic acid (Asp, D) and glutamic acid (Glu, E) (acidic side chains), and three are positive charged: lysine (Lys, K), arginine (Arg, R) and histidine (His, H) (basic side chains).
Detailed explanation-4: -If acid is added to a solution containing the zwitterion, the carboxylate group captures a hydrogen (H+) ion, and the amino acid becomes positively charged.
Detailed explanation-5: -Zwitterions contain both positive-and negative-charged groups, with an overall neutral charge.