MODULE 2: TRANSCRIPTION QUESTIONS WITH CORRECT ANSWERS

Why are E.coli the model bacterium? CORRECT ANSWER -no nucleus or introns -range amount of proteins from high to low -3000 proteins at one time -4300 genes -5mb genome What is the difference between constitutive and inducible genes? CORRECT ANSWER C- always expressed and not high regulation (ribosome) I- induced/expressed and high regulation in response to environment How is transcription and translation coupled in a prokaryote? CORRECT ANSWER begin transcription, RNA pol ribosomes jump on mRNA and start translation degradation 5' mRNA end before synthesis ends transcription and translation at a similar rate RNA pol terminates at 3' end degradation continues and R finish translation -rapid response- rapid off What determines the rate of the coupled transcription and translation? CORRECT ANSWER rate of initiation of transcription e.g. RNA polymerase What is an operon? CORRECT ANSWER set of co-transcribed genes under the control of a single regulated promoter the transcripts are polycistonic- multiple genes + proteins the genes have a related function has a promoter and terminator Broadly describe the CRISPR immunization process CORRECT ANSWER virus insert foreign DNA into cell cash proteins recognize and cleaves becomes a Novel spacer- 30 N long so specific insert DNA into repeat spacer unit to serve as memory Broadly describe the CRISPR immunity process CORRECT ANSWER for a second infection repete-spacer unit transcribed as noon coding RNA combine with cash proteins to guide cleavage of specific DNA of virus cash proteins are nucleases e.g. Cas 9 and double strand cut at specific sites after cleavage the foreign DNA degrades What is the structure of the CRISPR system? CORRECT ANSWER -cascade cash complex- cotranscribed and process/cleave DNA= operon