Question

What mRNA codon is changed in sickle cell anemia?

Answer 1

In sickle cell anemia, there is a change in the mRNA codon for the amino acid called "glutamic acid." Specifically, a single nucleotide substitution occurs in the gene that codes for the beta-globin protein, which is a component of hemoglobin. This substitution replaces the codon GAG, which codes for glutamic acid, with the codon GTG, which codes for the amino acid valine. This small change in the genetic code leads to the production of abnormal hemoglobin molecules, causing the red blood cells to become sickle-shaped.

Answer 2

In sickle cell anemia, the mRNA codon GAG is changed to GTG, resulting in the substitution of the amino acid valine for glutamic acid at the sixth position of the beta globin chain. This single change among the approximately 600 amino acids in the hemoglobin molecule significantly affects an individual's health.

Step-by-step explanation:

The mRNA codon changed in sickle cell anemia is a result of a single nucleotide substitution leading to a missense mutation in the hemoglobin gene. This point mutation occurs at the 17th nucleotide of the gene where adenine (A) is replaced by thymine (T). Consequently, it changes the mRNA codon from GAG to GTG, which in turn changes the amino acid from glutamic acid to valine at the sixth position of the beta globin chain.

In sickle cell anemia, only one out of the approximately 600 amino acids in the hemoglobin molecule is affected. However, this single amino acid substitution can have severe effects on the individual's health, dramatically decreasing life expectancy. This substitution leads to the characteristic sickle shape of the red blood cells, which impacts their ability to transport oxygen efficiently.