Question

1. What transcript is produced from this gene?

5’ ATTGTGAGCAGGAAGAGAGT 3’

3’ TAACACTCGTCCTTCTCTCA 5’

A) 5’AUUGUGAGCAGGAAGAGAGU3’

B) 5’ACUCUCUUCCUGCUCACAAU3’

C) 5’UAACACUCGUCCUUCUCUCA3’

D) 5’UGAGAGAAGGACGAGUGUUA3’

2.If the anticodon is 5’CAU 3’, what codon on the mRNA will it bind?

3.The lac operon is ON in which situation:

A) Low glucose low lactose

B) Low glucose high lactose

C) High glucose high lactose

D) High glucose low lactose

4.You have isolated an E. coli mutant that has a deletion of the gene encoding the cAMP receptor protein CRP. Under which conditions would lacZ, lacY and lacA be expressed in this mutant strain?

A) Low glucose low lactose

B) Low glucose high lactose

C) High glucose high lactose

D) High glucose low lactose

E) None of the above

5.Select the DNA sequence closest to the trp leader region that encodes an enzyme involved in tryptophan biosynthesis

A) trp p B) trp o C) trp C D) trp E E) trp A

trp leader region (not drawn to scale) Number of base pairs in indicated region 162 1560 1593 1350 1196 804 300 DNA trpD trpc trpB trpA Spacer trp p trp o t rpE Attenuator Spacer sequence (trp a) Regulation Enzyme production

Answer 1

1. A) 5’AUUGUGAGCAGGAAGAGAGU3’

2.ANTICODON     3' UAC 5'
mRNA               5' AUG 3'

3. B) Low glucose high lactose
Lac operon is ON when there is no glucose present in the media and lactose converts into allolactose and enter into cell and activates the LAc operon.

4. E) None of the above
Without CRP, cAMP not bind to the CAP region so RNA polymerase not able to bind Promoter region.

5. D) trp E