Which one of the following amino acids is present in vasopressin at position 3?

Correct option is B

The correct answer is: (2) Phenylalanine.

Explanation:
In vasopressin, the amino acid present at position 3 is phenylalanine. Vasopressin is a nonapeptide hormone consisting of 9 amino acids. The sequence of vasopressin is:

Cys-Tyr-Phe-Gln-Asn-Cys-Pro-Arg-Gly,
where Phenylalanine (Phe) is at position 3.

Information Booster:

1. Vasopressin (ADH) is a peptide hormone synthesized in the hypothalamus and stored in the posterior pituitary.

2. It plays a significant role in regulating water balance by acting on the kidneys, promoting water reabsorption.

3. The amino acid sequence of vasopressin is Cys-Tyr-Phe-Gln-Asn-Cys-Pro-Arg-Gly, and the third position contains phenylalanine (Phe).

Additional Knowledge:

• Tyrosine (Tyr) is at position 2 in the vasopressin sequence, not at position 3.

• Glutamine (Gln) is present at position 4 in vasopressin.

• Asparagine (Asn) is found at position 5 in the sequence.