Question

1. what is the difference in the amino acid sequence of the hemoglobin molecules synthesized by translating the sickle cell vs. normal hemoglobin mrna molecules?

Explanation:

Sickle cell anemia is caused by a point mutation in the DNA that leads to a change in the mRNA codon. The normal hemoglobin mRNA has a codon \( GAG \) which codes for glutamic acid. In sickle cell hemoglobin mRNA, due to a mutation, the codon becomes \( GUG \) (or \( GTG \) in DNA, which transcribes to \( GUG \) in mRNA depending on strand - reading; sometimes written as \( GAG \to GAA \) in some notations but the key is the amino - acid change). This change results in the substitution of glutamic acid (a polar amino acid) with valine (a non - polar amino acid) at the sixth position of the beta - globin chain.

Answer:

In the amino - acid sequence of hemoglobin, the sixth amino - acid in the beta - globin chain is changed. In normal hemoglobin, it is glutamic acid, while in sickle - cell hemoglobin, it is valine.