Question

3. Describe RNA processing in eukaryotes. That is, how does a ‘primary transcript’ become a mature mRNA?

4. Imagine a bacterial gene that is necessary for the synthesis of a vitamin needed by the cell. This vitamin is a ‘small molecule’ that can bind to the repressor of this gene. Do you think this binding will increase or decrease the ability of the repressor to bind to the operator of this gene? Why?

Answer 1

Question 3

RNA processing is the process of the removal of introns sequence from the RNA and joining of exon sequence that code for proteins. The RNA processing involve the spliceosome that is a protein complex and small RNA moleculrs which is required to remove the introns sequence. RNA processing is the one of the process involved in the post-transcriptional modification. The RNA formed from transcription is known as primary transcript which is not functional and required specific steps to be functional. Splicing is one of them.

Figure: RNA splicing in eukaryotes. Here, E is representing exon and i is reprenting introns.

Question 4

This binding will do not  affect much the binding of repressor protein to the operator .  This is because vitamin is mainly a allosteric effector that do not bring any change in the structure and function of the protein. Therefore, repressor will able to bind with operator in the lac operon.