Answer to Question #134806 in Organic Chemistry for Brayen

Question

Consider the tetrapeptide Val-Ile-Leu-Met. What is the net charge on this peptide at pH 6.56.56.56.56.56.5? (Examples: +1, 0, OR -1)

What is the charge on leucine at pH 7? [Examples: -1, 0, OR +1]

What is the charge on tyrosine at pH 1.5? [Examples: -1, 0, OR +1]

Glycine, aspartic acid, isoleucine, leucine and valine all have pKa2's very close to 9.60.

Which would be best to prepare a 1.0 M, pH 9.60 buffer?

What is the pI of the pentapeptide Cys-Leu-Glu-Ala-Lys?

Answer 1

tetrapeptide Val-Ile-Leu-Met. HAVE net charge on this peptide at pH 6.56 IS " + 1 "

charge on leucine at pH 7 IS " ZERO " .

charge on tyrosine at pH 1.5 IS " + 1 "