Name: Student #: MICB 211 TUTORIAL #3 WORKSHEET Complete the following questions and hand-in to Canvas by the end of your tutorial day. BACKGROUND Write notes about the background information your TA has presented Ara series of genes that encodes for proteins involved in metabolising sugars 4 binding sites that regulates 6 genes Works like a lac operon, AraR is a repressor Based on the arabinose operon, which promoter is controlling an "operon"? Which are controlling single genes? Pb is a promotor controlling an operon that controls one single gene. The rest of the promotors are If we assume that these promoters are controlled the same way the lac operon is, fill in the following table: Condition: Bound to the promoter/operator region? Yes or No AraR (repressor) CAP (activator) Glucose only yes no N Arabinose only no Both Glucose and Arabinose no No Glucose nor Arabinose yes yes Y yes yes OBJECTIVE What are the researchers trying to achieve? Wanted to look at gene expression of the arabinose operon is regulated by arabinose and glucose through AraR What is the hypothesis presented by the authors? The Ara operon is only activated when arabinose is present and Expression of arabinose metabolism genes? Y/N N Y Do they achieve it? Yes Accept or Refute? Accept
Name: Student #: glucose is absent; and AraR is a repressor FIGURE 1 What is being measured? Why do you think they measured gene expression this way? Could they have measured it a different way? Measuring transcription. The amount of mRNA being produced relative to the amount of activation. No, because measuring operon activation is harder to do. This is also the most accurate method since measuring the amount of protein is harder to do and less accurate. Identify the controls and treatments Control group(s): 0 mins groups Treatment group(s): ff0 and 60 mins How do the treatments affect expression of the following genes? Effect on expression levels (increase, decrease, stay the same) Gene Glucose Arabinose 30 min 60 min 30 min 60 min araA araE Decrease Decrease Decrease Increase Increase Increase Same Increase Both 30 min 60 min Increase Increase Same Increase If our assumption that these genes are regulated the same way that the lac operon is, are all the results expected? Are there any unexpected results? Explain. These results are expected. Are the promoters for araA and araE controlled in the same way in response to glucose and/or arabinose? They are controlled in the same way in response to the sugars in its environment ADDITIONAL NOTES OF INTEREST Note down at least one new thing that you might have learned from this session. Differentiating between
Name: Shanaya Virk Student #: 15891294