Question

suppose that an error in transcription occurred that changed the mrna sequence transcribed from a gene. imagine that now, the mrna is missing a specific base, like the one indicated in red below: ccc uac aug ggc aaa ccg ggu all the bases to the right of the red a would then be shifted over one position to the left. would this change the reading frame? no, the trnas and ribosome would adjust so that the normal amino acid sequence would be translated, despite the missing a. yes, the reading frame would now be aug ggc aac (instead of aaa) cgg (instead of ccg)... yes, but only one codon would be affected. the reading frame would now be aug ggc aa ccg ggu... key point 3: translation is a complex system with many interacting parts. its important to recognize, though, that although these readings have introduced a large number of molecules, machines, and events, the overview presented here was a highly simplified version of what researchers actually know about how proteins get made. for example, the readings have left out details about the many proteins that interact with mrna and the ribosome and that are essential for initiation, elongation, and termination. even studying simplified versions of complex systems like translation can be overwhelming at first. so as you work out how all of the parts interact with each other, you may find it enormously helpful to draw the process and make diagrams of how the different molecules and machines relate to each other, especially while working in a group. it can be particularly important to make drawings that help you compare transcription with translation, to help keep the two processes separate. did you fully understand the concept covered in this

Explanation:

The reading frame is determined by the 3 - base codon sequence. When a base is missing, the codons after the missing base are shifted. In the original sequence, the codons are \(CCC\), \(UAC\), \(AUG\), \(GGC\), \(AAA\), \(CCG\), \(GGU\). After the \(A\) (in red) is missing, the new codons (for the part after the missing base) are \(GGC\) (now part of a different codon group), \(AAC\) (instead of \(AAA\)) as the first new codon after the shift, \(CGG\) (instead of \(CCG\)) etc. This is a frameshift mutation. The tRNAs and ribosome do not "adjust" in the way described in the first option. Also, more than one codon is affected (so the third option is wrong).

Answer:

Yes, the reading frame would now be \(AUG\ GGC\ AAC\) (instead of \(AAA\)) \(CGG\) (instead of \(CCG\))...