Question

10 please and 7

You isolate plasmid DNA from bacteria (Questions 7-10) 7) A plasmid is an extrachromosomal circular DNA frequently found in prokaryotes. Aside from being smaller, how is it different from the prokaryotic genome? You place equal amounts of plasmid DNA in 4 different tubes and incubate the DNA with increasing amounts of the enzyme topoisomerase I for 1 hour (0 enzyme units 0.25 enzyme units, 0.5 enzyme units and 1 enzyme unit). You then analyze the plasmid DNA in each tube by agarose gel electrophoresis and obtain the figure shown below (the DNA was loaded at the top of the gel), the lane number is indicated at the bottom of the gel. Topoisomerase l Ou 0.25u 0.5u 1u 8) In the absence of any topoisomerase (see lane 1), the plasmid DNA adopts two forms that migrate at different speed even though they contain the same number of base pairs: one is the highly supercoiled plasmid form and the other is a closed circular plasmid form that arises when plasmid DNA gets nicked during the plasmid purification procedure. Which band would you expect to represent the highly supercoiled form ? a) the thin, fast-migrating band at the top the thick, fast-migrating band at the bottom c) the thin, slow-migrating band at the top d) the thick, slow-migrating band at the bottom to the highly supercoiled plasmid DNA after you added a large amount of topoisomerase 9) What happened I (lane 4) coils DJA will pecome line grate viower 10) What do the minor bands in lane 2 or 3 represent? nhncterial oene that produces a small peptide. The DNA sequence is predicted to

Answer 1

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