Question

At pH3, how many charged groups are present in the pentapeptide Ala-Asp-His-Ser-Lys?

Answer 1

At pH 3, the pentapeptide Ala-Asp-His-Ser-Lys has three charged groups.

Step-by-step explanation:

The pentapeptide Ala-Asp-His-Ser-Lys has five amino acids: Alanine (Ala), Aspartic acid (Asp), Histidine (His), Serine (Ser), and Lysine (Lys).

At pH 3, the acidic amino acids (Asp and Glu) will be negatively charged, while the basic amino acids (His, Lys, and Arg) will be positively charged.

In this case, the pentapeptide has one acidic amino acid (Asp) and two basic amino acids (His and Lys), so there are three charged groups present at pH 3.