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A Doody's Core Title for 2015.
Molecular Biology, 5/e by Robert Weaver, is designed for an introductory course in molecular biology. Molecular Biology 5/e focuses on the fundamental concepts of molecular biology emphasizing experimentation. In particular author, Rob Weaver, focuses on the study of genes and their activities at the molecular level. Through the combination of excellent illustrations and clear, succinct writing students are presented fundamental molecular biology concepts.
probe on s serves as the fluorescence donor, and the probe on the DNA serves as the fluorescence acceptor. Sometimes the probe on the DNA was at the 59, or upstream end (trailingedge FRET), which allowed the investigators to observe the drop in FRET as the polymerase moved away from the promoter and the 59-end of the DNA. In other experiments, the probe on the DNA was at the 39-, or downstream end (leading-edge FRET), which allowed the investigators to observe the increase in FRET as the
a DNA contains, the faster it will migrate in an electrophoretic gel. Figure 6.17b is a plot of the change in the superhelicity as a function of the number of active polymerases per genome at 378C. A linear relationship existed between these two variables, and one polymerase caused about 1.6 superhelical turns, which means that each polymerase unwound 1.6 turns of the DNA double helix. If a double helical turn contains 10.5 bp, then each polymerase melted about 17 bp (1.6 3 10.5 5 16.8). A
/Volume/204/MHDQ268/wea25324_disk1of1/0073525324/wea25324_pagefiles 6.3 Transcription Initiation (a) 135 (b) 2.5 Covalently closed, relaxed circle Remove polymerase Change in superhelicity 2.0 1.5 1.0 0.5 Strained circle (underwound) 0 0 0.5 1.0 1.5 Active polymerases per genome Supercoil Several hypotheses have been proposed, including the idea that the energy released by forming a short transcript (up to 10 nt long) is stored in a distorted polymerase or DNA, and the release
abound in nature, but this one differs from most of the others in that it was not created naturally in a cell. Instead, molecular biologists put it together in a test tube. SUMMARY Restriction endonucleases recognize specific sequences in DNA molecules and make cuts in both strands. This allows very specific cutting of DNAs. Also, because the cuts in the two strands are frequently staggered, restriction enzymes can create sticky ends that help link together two DNAs to form a recombinant DNA in
hybridized to the mRNA template. (b) Use RNase H to partially digest the mRNA, yielding a set of RNA primers base-paired to the first-strand cDNA. (c) Use E. coli DNA polymerase I to build second-strand cDNAs on the RNA primers. (d) The second-strand cDNA growing from the leftmost primer (blue) has been extended all the way to the 39-end of the oligo(dA) corresponding to the oligo(dT) primer on the first-strand cDNA. (e) To place sticky ends on the doublestranded cDNA, add oligo(dC) with terminal