Question

5.humans have a gene that codes for hemoglobin, the protein that red blood cells use to attach to oxygen molecules and carry the oxygen through the circulatory system. radiation exposure can cause a point mutation to occur in one of the codons in the gene. how would a point mutation affect the resulting hemoglobin protein? predict two possible outcomes.

Explanation:

1. Some point mutations are silent mutations: the changed codon still codes for the same amino acid (due to the redundancy of the genetic code). This leaves the hemoglobin's amino acid sequence, 3D structure, and oxygen-binding properties unchanged.
2. A missense point mutation can change the codon to code for a different amino acid. For example, the mutation causing sickle cell anemia replaces glutamic acid with valine in hemoglobin. This alters the protein's shape, making red blood cells sickle-shaped and reducing their ability to bind and carry oxygen effectively.

Answer:

1. The point mutation has no effect on the hemoglobin protein's structure or function.
2. The point mutation alters the hemoglobin protein's structure, impairing its oxygen-carrying ability.