Ap Biology Chap 16-19 Terms

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  • Topic: DNA, Gene, RNA
  • Pages : 5 (1676 words )
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  • Published : May 5, 2013
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Frederick Griffith| This person made an experiment that involved injecting mice with pneumonia: smooth S cells, rough R cells, heat-killed S cells, and heat-killed S cells with living R cells.| Avery, McCarty, and MacLeod| First to show that DNA was the genetic material, but not believed. Repeated Griffith's experiment, but subjected the strains to different enzymes, isolating RNA, DNA, lipids, carbohydrates, and proteins. Only the DNA killed the mice; the others had the mice survive.| Hershey and Chase| Used T4 bacteriophages in radioactive phosphorus to track DNA and radioactive sulfur to track proteins to determine what is the transformational material in genes. Radioactive phosphorus found in host bacteria, but no sulfur, proving once and for all DNA was the genetic material.| Erwin Chagraff| Analyzed the base composition of DNA and saw that it varied from species to species (shows the diversity of species). He also found that the amount of A nucleotides equaled the number of T nucleotides, and the number of C nucleotides equaled the number of G nucleotides.| Wilkins and Franklin| Used a technique called x-ray crystallography to produce a picture of the DNA molecule| Watson and Crick| Figured out structure of DNA was a double helix, and used Chagraff's observations to determine that purines pair with pyrimidines to maintain equidistance in the helix. (A with T and C with G)| Conservative Model| The parental double helix is copied as a full double helix; proved false| Semi-Conservative Model| The parental double helix is unzipped, and copied as individual template strands; Watson and Crick assumed this was correct, and it is| Dispersive Model| The parental double helix is copied in fragments; proved false| Meselson and Stahl| Proved that DNA replicates in a semiconservative fashion, confirming Watson and Crick's hypothesis. Cultured bacteria in a medium containing heavy nitrogen (15N) and then a medium containing light nitrogen (14N); after extracting the DNA, they demonstrated that the replicated DNA consisted of one heavy strand and one light strand| Origin of Replication| Site where the replication of a DNA molecule begins, consisting of a specific sequence of nucleotides.| Replication Bubble| A region of DNA, in front of the replication fork, where helicase has unwound the double helix| Replication Fork| A Y-shaped point that results when the two strands of a DNA double helix separate so that the DNA molecule can be replicated| DNA Helicase| An enzyme that unwinds the DNA double helix during DNA replication| Single-Strand Binding Proteins| Small proteins that bind to either of the template strands in replication to prevent them from coming together again| Topoisomerase| A protein that functions in DNA replication, helping to relieve strain in the double helix ahead of the replication fork.| RNA Primer| A small RNA sequence that is complementary to a DNA sequence, and allows a new DNA strand to begin being formed| Primase| An enzyme that joins RNA nucleotides to make the primer using the parental DNA strand as a template.| DNA Polymerase| Enzyme involved in DNA replication that brings individual nucleotides to produce a new DNA molecule| Antiparallel| How new DNA strands must be built. If the parental strand was from 3- to 5-, the new strand must be built 5- to 3-, and vice versa| Leading Strand| The parental 3- to 5- strand which builds from 5- to 3-, the mandatory direction, allowing for continuous growth| Lagging Strand| The parental 5- to 3- strand, which builds from 3- to 5-, which is impossible, so it must be built in Okazaki Fragments| DNA Ligase| An enzyme that joins together the Okazaki Fragments of the Lagging Strand| Mismatch Repair| The cellular process that uses specific enzymes to remove and replace incorrectly paired nucleotides.| Nulcease| An enzyme that cuts out a damaged portion of DNA, which is then cleaved together using DNA...
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