Understand how transcription occurs in prokaryotes and the significance of the sigma factor-promoter interactions. Understand how translation occurs and the cellular components required for translation. Three base-pair additions or deletions may affect the function of the protein, but will allow the reading frame to remain proper. The addition or deletion of one base pair will change the reading frame and destroy protein function. Prokaryotic genes have different promoter sequences than eukaryotic genes.
Eukaryotes also have enhancer regions to control gene expression.
Because one gene makes one polypeptide. Many enzymes are multimeric, having several polypeptides. A frameshift mutation has occurred in the gene shifting the reading frame. In this example, the shift in reading frame produces a new protein sequence, but in the new reading frame a termination codon is encountered causing termination of translation. The function of this protein will be completely abolished due to the loss and change of amino acid sequence.