How would you expect your results to change if the enzyme did not have time to cut all of the sites? (Hint, remember that there are many pieces of the lambda DNA in the tube – draw yourself a simplified model where there are four restriction sites, and imagine what would happen if the enzyme only cut at one, two, three or all four, randomly, each time). How would you expect your results to change if you treated them with both EcoRI and HindIII in the same tube? Why might it be safer for the virus to have its DNA become circular when it enters the host, rather than remain linear?

How would you expect your results to change if the enzyme did not have time to cut all of the sites? (Hint, remember that there are many pieces of the lambda DNA in the tube – draw yourself a simplified model where there are four restriction sites, and imagine what would happen if the enzyme only cut at one, two, three or all four, randomly, each time). How would you expect your results to change if you treated them with both EcoRI and HindIII in the same tube? Why might it be safer for the virus to have its DNA become circular when it enters the host, rather than remain linear?

Biology Today and Tomorrow without Physiology (MindTap Course List)

5th Edition

ISBN:9781305117396

Author:Cecie Starr, Christine Evers, Lisa Starr

Publisher:Cecie Starr, Christine Evers, Lisa Starr

Chapter10: Biotechnology

Section: Chapter Questions

Problem 1CT

See similar textbooks

Similar questions

The restriction endonuclease NciI recognizes and cuts the five-base-pair sequence 5’- CC(G/C)GG-3’ [where (G/C) means either G or C will work at that position]. (1) How often, on average, would this sequence occur in random DNA? Assume the DNA contains 25% each of A, G, T & C. (2) After digestion, Nci1 leaves a one-base 5’ overhang. Write/draw the cut site/digested products.
What, if any, are potential restriction enzyme recognition sequences in this DNA? (Only consider sequences of 6 bp or longer.) Using any of the sites which you identified in above, illustrate cleavage positions for that site which will result in a 5’ overhang or a 3’ overhang respectively.
If the sequence of base pairs along a DNA molecule occurs strictly at random, what is the expected frequency of a specific restriction enzyme recognition sequence of length (a) four and (b) six base pairs?
A linear piece of DNA that is 14 kb long is cut first by EcoRI alone, then by SmaI alone, and finally, by both EcoRI and SmaI together. The following results are obtained: Draw a map of the EcoRI and SmaI restriction sites on this 14-kb piece of DNA, indicating the relative positions of the restriction sites and the distances between them.
How often, on average, would you expect a type II restriction endonuclease to cut a DNA molecule if the recognition sequence for the enzyme had 5 bp? (Assume that the four types of bases are equally likely to be found in the DNA and that the bases in a recognition sequence are independent.) How often would the endonuclease cut the DNA if the recognition sequence had 8 bp?
Knowing that you are using HindIII and EcoRI to cut your plasmids, and that those two enzymes cut within the MCS, use the map of pUC19 provided below to compute: What will be the sizes of the 2 restriction fragments if NO insert is present in pUC19? What will be the sizes of the 2 restriction fragments if the approximately 317 bp RT-PCR product (insert from WT satC dimer) was ligated successfully into the SmaI site? What will be the sizes of the 2 restriction fragments if TWO approximately 317 bp RT-PCR products (2 ligated inserts from WT satC dimer) were ligated into the SmaI site?
Table 21.3 describes the cleavage sites of five different restrictionenzymes. After these restriction enzymes have cleaved the DNA, four of them produce sticky ends that can hydrogen bond with complementary sticky ends, as shown in Figure 21.1. The efficiency of sticky ends binding together depends on the number of hydrogen bonds; more hydrogen bonds makes the ends “stickier” and more likely to stay attached. Rank these four restriction enzymes from Table 21.3 (from best to worst)with regard to the efficiency of their sticky ends binding to each other.
A linear DNA molecule is subjected to complete restriction digestion by (1) EcoRI alone, (2) HindIII alone, and (3) both enzymes together. The DNA fragments are then separated using gel electrophoresis. Results are shown below: (i) (ii) (iii) EcoRI Hindill Both | | — | | 10 kb 9 kb 8 kb 5 kb 2 kb 1 kb How long is the original DNA molecule? How many EcoRI recognition sites does it have? Does the longest EcoRI fragment contain a HindIII restriction site? Explain your answer.
All are correct about DNA gyrase in E. coli EXCEPT: It works to remove positive supercoiling introduced by the DnaB protein (helicase). It is a topoisomerase that hydrolyzes ATP during its reaction mechanism. Its mechanism involves the breaking of a single phosphoester bond in one strand of dsDNA. It works to relieve supercoiling in DNA to overcome the torsion stress imposed upon unwinding.
Consider the following plasmid (size 8000 bp), with restriction sites at the positions indicated: (see image) a) This plasmid is digested with the enzymes listed below. Indicate how many fragments will begenerated in each case, and give the sizes of the fragments.PstIXhoICombination of PstI + XhoI + EcoRI (triple digest) b) Draw the banding pattern you would expect to observe if each of these digestions is loaded into a separate well of an agarose gel, and the fragments separated by electrophoresis. In the first well you load a DNA marker (M) containing fragments with sizes of 1000 bp, 2000 bp, 4000 bp and 8000 bp. c) This gel is transferred to a membrane in a Southern blot experiment, and hybridised to a radioactively labelled 200 bp probe, which anneals to the plasmid DNA at the position indicated on the diagram above. Draw the autoradiographic profile you would expect to observe for the membrane.
A group of overlapping clones, designated A through F, is isolated from one region of a chromosome. Each of the clones is separately cleaved by a restriction enzyme, and the pieces are resolved by agarose gel lectrophoresis,with the results shown below. There are nine different restriction fragments in this chromosomal region, with a subset appearing in each clone. Using this information, deduce the order of the restriction fragments in the chromosome.
A virus with a circular double-stranded DNA chromosome contains approximately 10,000 bp. You want to begin characterizing this chromosome by making a map of the cleavage sites of three restriction endonucleases: EcoRI, Hind III, and BamHI. You digest the viral DNA under conditions that allow the endonuclease reactions to go to completion and then subject the digested DNA to electrophoresis on agarose to determine the lengths of the restriction fragments produced in each reaction. Based on the resulting data, draw a map of the viral chromosome indicating the relative positions of the cleavage sites for these restriction endonucleases: Endonuclease EcoRI HindIII BamHI EcoRI + HindIII EcoRI + BamHI HindIII+ BamHI EcoRI + HindIII + BamHI Length of fragments (kb) 6.9, 3.1 5.1, 4.4, 0.5 10.0 3.6, 3.3, 1.5, 1.1, 0.5 5.1, 3.1, 1.8 4.4, 3.3, 1.8, 0.5 3.3, 1.8, 1.5, 1.1, 0.5