MBG 1000 Chapter Notes - Chapter 9: Dna Extraction, Dna Replication, Deoxyribose

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limecicada923

17 Apr 2016

School

University of Guelph

Department

Molecular Biology and Genetics

Course

MBG 1000

Professor

Christine Schisler

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Document Summary

Dna replicates and contains information for protein synthesis. Miescher isolated dna in white blood cell nuclei in 1869. In the 1940s, griffith identified something that could be passed from one bacterium to another, which avery, macleod and mccarty showed was dna. Hershey and chase confirmed that dna, and not protein, is the genetic material. Dna encodes information that the cell uses to synthesize protein. Dna can also replicate, passing on it"s information. The dna double helix"s backbone is alternating deoxyribose and phosphate held together by complementary pairs of a-t and g-c bases. A and g are purines; t and c are pyrimidines. The dna double helix is antiparallel, it"s strands running in an opposite head-to-toe manner. Dna winds tightly about histone proteins, forming nucleosomes, which wind tighter, forming chromatids. It consists of a deoxyribose, a phosphate and a nitrogenous base. Experiments that followed the distribution of labeled dna showed that dna replication is semiconservative, not conservative or dispersive.

Related Questions

Please answer all the questions

Define

1. Chargaffâs rule â

2. Semiconservative replication â

Fill in the Blank

3. Adjacent nucleotides are held together by a covalent bond called a _____________________ bond.

4. ________________________________ is the enzyme the adds nucleotides to the free 3â hydroxyl group on a growing stand of DNA.

True or False

5. Hershey and Chase determined that DNA was the material of heredity when radiolabeled sulfur from a virus was injected in to an E. coli cell.

6. After coinfecting E. coli with âheavyâ and âlightâ viral DNA, Meselson and Weigle observed a range of densities in the CsCl gradient which was evidence for recombination between the two stands of DNA.

Short Answer

7. Describe what happens when DNA replicates making sure to include the enzymes involved in the process.

8. Describe the experiments by Griffith, Avery, MacLeod, and McCarty that provided evidence for transformation and identified the transforming principle?

magine that the year is 1928 and the scientific world is in an uproar trying to determine what component of the cell isresponsible for genetic inheritance. Is it DNA, protein, perhaps even RNA? You are busy in your lab, trying to help solve this crucial mystery that still plagues (then) modern day biology. Your work focuses on a microorganism, a bacterium named Streptococcus pneumoniae, and its effects on mice. There are two strains of S. pneumoniae (which is responsible for pneumonia), the âRoughâ strain (R) and âSmoothâ strain (S). The strains are very similar except the S strain has a smooth polysaccharide coat that enables the microorganism to avoid the organismâs immune system and cause illness (and death in mice). The R strain has a rough coat which is detected and dealt with by the immune system (and as a result causes no death in mice). You decide to perform a series of experiments using the R and S strain of S. pneumoniae involving injections of these strains in mice. Your results are documented in the figure below: living S strain of S. pneumoniae mouse dies of infection living R strain of S. pneumoniae mouse lives mouse lives S strain heat-killed living R strain mouse dies of infection living, pathogenic S strain recovered S strain heat-killed From these results, you figure out that something from the heat killed S strain is transforming the R strain into the virulent strain. What is this âTransforming principleâ? Is it related to the cellular component that was passed from one generation to the next? As you know, this was the initial experiment performed by Dr. Frederick Griffith that eventually led to the discovery of the true cellular component that is the genetic inheritance molecule as well as the âtransforming principleâ (Hint: Itâs DNA!).

1. Several experiments were required to demonstrate how traits are inherited. Which scientist or team of scientists first demonstrated that cells contain some component that can be transferred to a new population of cells and permanently cause changes in the new cells?

a. Griffith b. Watson and Crick c. Avery, MacLeod, and McCarty d. Hershey and Chase

2. From your results, which one of the cellular components can be determined NOT to be the component responsible for genetic inheritance? Why?

a. Proteins because these macromolecules become denatured with heat. b. DNA because these macromolecules form a single helix in solution. c. RNA because it's double stranded 100% of the time d. Sugars because glycolysis happens.

3. Which one of the following experimental trials below are considered to be controls for this experiment? a. S Strain grown in 10% ethanol medium. b. Living S strain; Living R strain; Heat Killed S Strain c. Living R Strain with heat killed S strain; Living S Strain d. Heat Killed S strain; Living R strain; R strain grown in 10% ethanol medium

4. Which scientist or team of scientists obtained definitive results demonstrating that DNA is the genetic molecule? a. Griffith b. Watson c. Crick d. Hershey and Chase

5. Hershey and Chase used radiolabeled macromolecules to identify the material that contains heritable information. What radioactive material was used to track DNA during this experiment?

a. 3H b. 14C c. 35S d. 32P

6. DNA molecules, like proteins, consist of a single, long polymeric chain that is assembled from small monomeric subunits.

a. True b. False

7. The polarity of a DNA strand results from the polarity of the nucleotide subunits.

a. True b. False

8. There are five different nucleotides that become incorporates into a DNA strand.

a. True b. False

9. Hydrogen bonds between each nucleotide hold individual DNA strands together.

a. True b. False

brownpanda894

Chapter 10

1.Outline the history of our knowledge on DNA up to Watson and Crick. What were the main contributions made by each researcherâs key experiment?

2.Explain the setup of the Hershey and Chase experiment, what would the results have been if protein was the genetic material?

3.Draw the structure of a DNA nucleotide, labeling each main component correctly. How does an RNA nucleotide differ?

4.If a section of double stranded DNA contains 19% Adenine, how much Thymine is present?

5.You are a researcher studying the genetic basis of heart attacks and have been working to determine the expression levels of different genes that might contribute to cancer formation. You obtain the DNA methylation status of five genes of interest (the data are shown in the table below). The plus (+) sign indicates the level of DNA methylation; more plus signs correlates with increased methylation levels.Based on this information which genes would you predict to have the highest rate of transcription?

Gene	Methylation levels
1	++
2	+++++
3	+++
4	++
5	+

What are the characteristics of the 3 main DNA forms?

Chapter 11

What are the different types of chromatin?

What are the structures and important roles for telomeres and centromeres?

What are the differences found between eukaryotic chromosomes and mitochondrial?

Chapter 12

Explain each of the different models of replication.

If you grow a culture of bacteria in media with radioactive nucleotides so that all DNA in the cells include radioactive nucleotides and then place the bacteria in new non radioactive media. After two rounds of replication what proportion of the DNA molecules will contain radioactivity?

Summarize the similarities and differences between rolling-circle replication, theta replication and linear eukaryotic replication.

What are the functions of the different DNA polymerases found in eukaryotic cells?

Draw a replication fork and include all key components and orientations. (Leading/lagging strands, DNA helicase, RNA primer and DNA gyrase)

What is the Holliday model of recombination and what are the necessary steps?

Chapter 13

What are the different types of RNA and what roles do they play?

Describe the properties and functions of each of the RNA polymerases and how they differ depending on the organism.

Describe in detail the process and mechanisms of transcription in both prokaryotes and eukaryotes.

Chapter 14

What are the primary purposes of each of the three post transcriptional modifications that occur in eukaryotic cells.

What is alternative splicing and what role does it play in the cell?

How is ribosomal RNA processed after transcription?

How do siRNA and miRNA work, describe/draw out the process in detail.

MBG 1000 Chapter Notes - Chapter 9: Dna Extraction, Dna Replication, Deoxyribose

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