Plasmid donor Gene donor 1→. Isolation of bacterial plasmid A plasmid is a genetic structure that is circular Isolated gene Plasmid opened with restriction enzyme 2 > DNA ligase binds ends together Recombinant DNA molecule Transformation of fresh bacterium Chromosome So Donor gene Transcription MANA Transtation Protein product

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?

Bacteriophage-Inspired Antibiotics Although bacteriophages have been infecting bacteria for billions of years, no mechanism, has evolved in bacteria to prevent the viruses from lysing the cell walls of their hosts. Now, scientists are targeting the same bacterial wall components that bacteriophages do. The goal is to develop antibiotics that bacteria will be less likely to develop resistance to. FIGURE 20.22 shows the results of a study to test Epimerox, a new bacteriophage-inspired antibiotic, against Bacillus anthracis, the bacterial species that causes the disease anthrax. FIGURE 20.22 Effect of Epimerox on the survival of mice with anthrax. Mice were infected with the bacteria B. anthracis. One group of 15 then began receiving a drug-free buffer solution 3 hours later. Another 15 were treated with Epimerox beginning 3 hours after infection. A third group of 15was treated with Epimerox beginning 24 hours after infection. In studies with Bacillus anthracis cells grown in culture, no Epimerox-resistant cells were observed. Explain why this result is consistent with the scientists' goal for developing this drug.

Bacteriophage-Inspired Antibiotics Although bacteriophages have been infecting bacteria for billions of years, no mechanism, has evolved in bacteria to prevent the viruses from lysing the cell walls of their hosts. Now, scientists are targeting the same bacterial wall components that bacteriophages do. The goal is to develop antibiotics that bacteria will be less likely to develop resistance to. FIGURE 20.22 shows the results of a study to test Epimerox, a new bacteriophage-inspired antibiotic, against Bacillus anthracis, the bacterial species that causes the disease anthrax. FIGURE 20.22 Effect of Epimerox on the survival of mice with anthrax. Mice were infected with the bacteria B. anthracis. One group of 15 then began receiving a drug-free buffer solution 3 hours later. Another 15 were treated with Epimerox beginning 3 hours after infection. A third group of 15was treated with Epimerox beginning 24 hours after infection. What do these data indicate regarding the optimal time to begin Epimerox treatment?

Bacteriophage-Inspired Antibiotics Although bacteriophages have been infecting bacteria for billions of years, no mechanism, has evolved in bacteria to prevent the viruses from lysing the cell walls of their hosts. Now, scientists are targeting the same bacterial wall components that bacteriophages do. The goal is to develop antibiotics that bacteria will be less likely to develop resistance to. FIGURE 20.22 shows the results of a study to test Epimerox, a new bacteriophage-inspired antibiotic, against Bacillus anthracis, the bacterial species that causes the disease anthrax. FIGURE 20.22 Effect of Epimerox on the survival of mice with anthrax. Mice were infected with the bacteria B. anthracis. One group of 15 then began receiving a drug-free buffer solution 3 hours later. Another 15 were treated with Epimerox beginning 3 hours after infection. A third group of 15was treated with Epimerox beginning 24 hours after infection. How long did it take for all the mice that received the drug-free buffer alone to die? What function did this group play in the experiment?

Reverse transcriptase assembles an ________ on an _______ template. a. mRNA; DNA c. DNA; ribosome b. cDNA; mRNA d. protein; mRNA

There have been recurring cases of mad-cow disease in the United Kingdom since the mid-1990s. Mad-cow disease is caused by a prion, an infectious particle that consists only of protein. In 1986, the media began reporting that cows all over England were dying from a mysterious disease. Initially, there was little interest in determining whether humans could be affected. For 10 years, the British government maintained that this unusual disease could not be transmitted to humans. However, in March 1996, the government did an about-face and announced that bovine spongiform encephalopathy (BSE), commonly known as mad-cow disease, can be transmitted to humans, where it is known as variant Creutzfeldt-Jakob disease (VCJD). As in cows, this disease eats away at the nervous system, destroying the brain and essentially turning it into a spongelike structure filled with holes. Victims experience dementia; confusion; loss of speech, sight, and hearing; convulsions; coma; and finally death. Prion diseases are always fatal, and there is no treatment. Precautionary measures taken in Britain to prevent this disease in humans may have begun too late. Many of the victims contracted it over a decade earlier, when the BSE epidemic began, and the incubation period is long (VCJD has an incubation period of 10 to 40 years). A recent study concluded that 1 in 2,000 people in Great Britain carry the abnormally folded protein that causes VCJD. In spite of these numbers, the death rate from VCJD remains low. It is not clear whether this means that the incubation period for the disease is much longer than previously thought, or whether they may never develop the disease. How can a prion replicate itself without genetic material?

What Art the Features of the Series of -omes? Define the following terms: a. Genome b. Transcriptome c. Proteome d. Metabolome e. Fluxome

Which of the following sequences on a DNA molecule would be complementary to GCTTATAT? TAGGCGCG ATCCGCGC CGAATATA TGCCTCTC

Match the terms with the best description. __ genetic message a. protein-coding segment __ promoter b. KN A polymerase binding site __ polysome c. read as base triplets __ exon d. removed before translation __ genetic code e. occurs only in groups __ intron f. complete set of 64 codons