Describe and explain the effect that an extra uracil base added to the mRNA strand, would have on the polypeptide chain produced?
Please can you answer this question in stages in a simple way but ofcourse use the correct terminology.
If the mRNA strand reads, for example, AUGCGAAGA, this stands for the following amino acids: the first triplet or AUG stands for Methionine or start. The second triplet CGA is the amino acid Arginine and the third triplet AGA stands for arginine as well.
Consider if an extra uracil was added in the chain below. Note the extra uracil which is in bold print.
By adding an extra uracil as seen in the second sequence the code reads, AUG or start, CGA or arginine, UAG which signals stop and then the base A at the end is not part of a triplet. This stop signals the end of the transcription and results in a shorter protein chain. This would cause a mutation. This illustrates a frameshift mutation as everything after the inserted base is shifted and the triplets after the inserted base will be incorrect.