QUESTION 15 The researchers Hershey and Chase conducted an experiment where they radioactively labeled the proteins of a T2 phage with 35S. In a separate treatment, they labeled the DNA of a T2 phage with 32p. They allowed the labeled T2 phage to infect E. coli and then agitated the cells so that the phage would fall off of the cells. The cells were then spun down to the bottom of the tubes. When the proteins were labeled, did the researchers see radioactivity in the pelleted cells or the supernatant (liquid on top of pellet)? When the DNA was labeled, did the researchers see radioactivity in the pelleted cells or the supernatant? What conclusion did Hershey and Chase draw from this experiment?

QUESTION 15 The researchers Hershey and Chase conducted an experiment where they radioactively labeled the proteins of a T2 phage with 35S. In a separate treatment, they labeled the DNA of a T2 phage with 32p. They allowed the labeled T2 phage to infect E. coli and then agitated the cells so that the phage would fall off of the cells. The cells were then spun down to the bottom of the tubes. When the proteins were labeled, did the researchers see radioactivity in the pelleted cells or the supernatant (liquid on top of pellet)? When the DNA was labeled, did the researchers see radioactivity in the pelleted cells or the supernatant? What conclusion did Hershey and Chase draw from this experiment?

Biology: The Unity and Diversity of Life (MindTap Course List)

14th Edition

ISBN:9781305073951

Author:Cecie Starr, Ralph Taggart, Christine Evers, Lisa Starr

Publisher:Cecie Starr, Ralph Taggart, Christine Evers, Lisa Starr

Chapter8: Dna Structure And Function

Section: Chapter Questions

Problem 3DAA: HersheyChase Experiments The graph shown in FIGURE 8.5 is reproduced from an original 1952...

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A amp PBR322 4301 fot B Clear Zones Figure 2 The postgraduate student, Demika, inserted her gene of interest into the plasmid, pBR322, before transformation into the competent host cell using heat shock method. After that she cultured the cells on the Ampicillin agar plate before replica plating the colonies onto another Ampicillin (A) and Tetracycline (B) agar plates shown in Figure 2. (1) Referring to the vector pBR322 in Figure 2, which recognition site was cleaved to insert the gene of interest? Based on the observation above, can you identify which colonies are carrying positive mcombinants of BR322? Explain your selection.
HersheyChase Experiments The graph shown in FIGURE 8.5 is reproduced from an original 1952 publication by Hershey and Chase. Bacteriophage were labeled with radioactive tracers and allowed 10 infect bacteria. The virusbacteria mixtures were then whirled in a blender to dislodge any viral components attached to the exterior of the bacteria. Afterward, radioactivity from the tracers was measured. FIGURE 8.5 Detail of Alfred Hershey and Martha Chases 1952 publication describing their experiments with bacteriophage. Infected bacteria refers to the percentage of bacteria that survived the blender. How did the researchers know that the radioisotopes in the fluid came from outside of the bacterial cells and not from bacteria that had been broken apart by whirling in the blender?
HersheyChase Experiments The graph shown in FIGURE 8.5 is reproduced from an original 1952 publication by Hershey and Chase. Bacteriophage were labeled with radioactive tracers and allowed 10 infect bacteria. The virusbacteria mixtures were then whirled in a blender to dislodge any viral components attached to the exterior of the bacteria. Afterward, radioactivity from the tracers was measured. FIGURE 8.5 Detail of Alfred Hershey and Martha Chases 1952 publication describing their experiments with bacteriophage. Infected bacteria refers to the percentage of bacteria that survived the blender. After 4 minutes in the blender, what percentage of each isotope was extracellular?
HersheyChase Experiments The graph shown in FIGURE 8.5 is reproduced from an original 1952 publication by Hershey and Chase. Bacteriophage were labeled with radioactive tracers and allowed 10 infect bacteria. The virusbacteria mixtures were then whirled in a blender to dislodge any viral components attached to the exterior of the bacteria. Afterward, radioactivity from the tracers was measured. FIGURE 8.5 Detail of Alfred Hershey and Martha Chases 1952 publication describing their experiments with bacteriophage. Infected bacteria refers to the percentage of bacteria that survived the blender. The extracellular concentration of which isotope increased the most with blending?
HersheyChase Experiments The graph shown in FIGURE 8.5 is reproduced from an original 1952 publication by Hershey and Chase. Bacteriophage were labeled with radioactive tracers and allowed 10 infect bacteria. The virusbacteria mixtures were then whirled in a blender to dislodge any viral components attached to the exterior of the bacteria. Afterward, radioactivity from the tracers was measured. FIGURE 8.5 Detail of Alfred Hershey and Martha Chases 1952 publication describing their experiments with bacteriophage. Infected bacteria refers to the percentage of bacteria that survived the blender. Before blending what percentage of each isotope. 35S and 32P, was extracellular (outside the bacteria)?
HersheyChase Experiments The graph shown in FIGURE 8.5 is reproduced from an original 1952 publication by Hershey and Chase. Bacteriophage were labeled with radioactive tracers and allowed 10 infect bacteria. The virusbacteria mixtures were then whirled in a blender to dislodge any viral components attached to the exterior of the bacteria. Afterward, radioactivity from the tracers was measured. FIGURE 8.5 Detail of Alfred Hershey and Martha Chases 1952 publication describing their experiments with bacteriophage. Infected bacteria refers to the percentage of bacteria that survived the blender. Do these results imply that viruses inject DNA or protein into bacteria? Why or why not?
Question:- There is some recent research on the use of bacteriophages to inhibit pathogenic bacteria as alternative to antibiotics, for example, in poultry. Speculate what are the potential advantages and weaknesses of such phage therapy vs standard antibiotic treatment.
A plaque assay is performed beginning with 1 mL of a solution containing bacteriophages. This solution is serially diluted 4 times by combining 0.1 mL of each sequential dilution with 9.9 mL of liquid medium. Then 0.1 mL of the final dilution is plated in the plaque assay and yields 21 plaques. What is the initial density of bacteriophages in the original 1 mL? Recall that initial phage density = (plaque number/mL) ×× (dilution factor).
In Hershey-Chase experiment, bacteriophages protein coats were tagged with radioactive isotope S-32. These phages were used to infect E. coli cells and the cells were further centrifuged to form pellets. Why was the radioactivity level of S-32 found greater outside the cells compared to the E. coli cell pellets? Explain briefly. If the experiment is repeated in the same manner but this time the phage protein coats are labelled with isotope X and the phage DNA with isotope Y, which isotope’s radioactivity will be found in greater amounts in the E. coli cell pellets after centrifugation? Explain briefly.
About the technique of phage display: MOLECULAR BIOLOGY_advanced The Escherichia coli cell infected by the phage codifies for the optimized ligand when the phage DNA integrates in the DNA of the bacteria. Phages are selected if they express on their surface the optimized ligand. One selects Escherichia coli cells that are resistant to the phage infection. More than one optimized ligand can be selected during the panning procedure. The ligand to be selected on the surface of the phage is non-covalently linked to one of the surface proteins.
question: Can you summarize and explain for me what you want to tell in the article below? When I read it myself, I do not understand exactly what is meant by the article. It would be nice if you could highlight the important points. You can use them in a figure or diagram to explain. thank you and hava a nice day :) Article: Interference with Cellular Uptake, Immobilization, and Inactivation of the Virus Outside of the Host Cell Nanomaterials can be synthesized with a high specific surface area of a few hundred square meters per gram. Therefore, dependent on the surface properties, nanomaterials efficiently adsorb biomolecules and form a so-called biomolecular corona. This passive, nontargeted adsorption might be utilized to bind viruses, provided that the selected nanomaterial is relatively biocompatible. Viral surface proteins are often modified by sugar moieties or encompass positively charged amino acid patches that bind to lectins or glycosaminoglycans (GAGs) of heparan sulfate…
Considering counting rules, calculate the initial titre of the sample viral stock if the following plaques were counted in a plaque assay. Show clear sample calculations. Table 1: Plaque assay counts for lambda phage stock titre enumeration of average concentration (PFU/mL) Total dilution of viral stock 1/13500000 1/135000000 1/135000000 plated Volume diluted viral stock 0.1 0.1 0.1 plated (mL) PFU replicate 1 TNTC 275 25 Calculated concentration (PFU/mL) replicate 1 PFU replicate 2 TNTC 239 23 Calculated concentration (PFU/mL) replicate 2 Average concentration (PFU/mL)