Question

Isoleucine has the zwitterion structure shown. Draw the structure and give the net charge of isoleucine that will predominate at the indicated pH values (pI = 6.0).b. pH 6.0

Accepted Answer

Understand the concept of a zwitterion: A zwitterion is a molecule that contains both positive and negative charges but is overall electrically neutral. Amino acids like isoleucine exist as zwitterions at their isoelectric point (pI). The pI is the pH at which the amino acid has no net charge. Identify the functional groups in isoleucine: Isoleucine has an amino group (-NH3+), a carboxyl group (-COO−), and a side chain. At pH 6.0 (the pI), the amino group is protonated (+1 charge), and the carboxyl group is deprotonated (-1 charge). These charges balance each other, resulting in a net charge of 0. Determine the behavior of isoleucine at pH 6.0: Since the pH matches the pI, the zwitterion form of isoleucine will predominate. This means the molecule will have no net charge, as the positive charge on the amino group and the negative charge on the carboxyl group cancel each other out. Draw the structure of isoleucine at pH 6.0: Represent the zwitterion form with the amino group protonated (-NH3+) and the carboxyl group deprotonated (-COO−). Ensure the side chain is correctly depicted based on isoleucine's structure. Summarize the net charge: At pH 6.0, isoleucine exists predominantly in its zwitterion form, and the net charge of the molecule is 0.

Isoleucine has the zwitterion structure shown. Draw the structure and give the net charge of isoleucine that will predominate at the indicated pH values (pI = 6.0).
b. pH 6.0

비슷한 문제에 대한 검증된 영상 답변:

주요 개념

Zwitterion Structure

Isoelectric Point (pI)

pH and Charge Relationship