Final answer:
In a simulated protein synthesis experiment using synthetic RNA of repeated cytosine, a polypeptide chain composed only of the amino acid proline would be produced. This process is reflective of how a single nucleotide change can cause diseases such as sickle cell anemia by altering the amino acid sequence of hemoglobin
Step-by-step explanation:
If you could synthesize one of the polypeptides in hemoglobin from individual amino acids, and you then placed the resulting chain in an aqueous solution, you would be observing a process similar to protein synthesis. Hemoglobin is a critical protein in red blood cells that carries oxygen and it's composed of four polypeptide chains. In conditions such as sickle cell anemia, a single nucleotide mutation in the hemoglobin gene leads to a single amino acid change from glutamic acid to valine.
This seemingly minor change at the genetic level results in a significant alteration of the hemoglobin's structure and function, causing red blood cells to distort into a sickle shape. The abnormal cells can obstruct blood flow and lead to numerous health issues. Understanding how changes in the amino acid sequence of a polypeptide can affect protein structure and function is essential in the study of genetics and diseases.
In the experiment similar to Nirenberg and Matthaei's, if synthetic RNA containing only the base cytosine was added to each tube, it would lead to the production of a polypeptide chain comprised solely of the amino acid proline. This is because the codon CCC (made entirely of cytosine bases) codes for proline in the genetic code. Therefore, the repeated presence of cytosine in the RNA would translate into continuous incorporation of proline into the growing polypeptide chain.