Chapter 10

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Chapter 10
2011-03-15 21:24:17

chapter 10
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  1. Without using helicase, how can DNA be unwound in the lab?
    Heating the DNA just below boiling causes the two strands to seperate
  2. What is the origin/function of restriction enzymes
    • Recognize forigen DNA and can break phosphodiester bonds between adjacent nucleotides on both strands of DNA. This breaks the strand
    • In bacteria cell, this ability protects against incompatiable DNA of bacteriophages or plasmids.
  3. What is the function of RE in lab?
    Enzymes can be used to cleave DNA at desired sites and are important for techniques of recombinant DNA technology.

    They can combine two different strands of DNA and are a huge important part of genetic engineering.
  4. Defin palindromes
    • Sequences of DNA that are identical when read from the 5'-3' direction on one strand, and the 5'3' direction on the other.
    • The RE's can recognize and clip at base sequences called palindromes.
  5. Why are stickey ends important in the functioning of RE?
    • They will base pair with complimentary tails on other DNA fragments/plasmids
    • This makes it possible to splice genes into specific sites.
  6. Define polymerase chain reaction
    • Rapidly increases the amount of DNA in a sample without the need for making cultures or carrying out complex purification techniques.
    • It holds the potential to detect cancer from a single cell or to diagnose an infection from a single gene copy.
    • Makes it possible to replicate a target DNA from a few copies to billions in hours.
  7. Thermocycler!
    Significance of thermophilic bacteria and thermocycler in PCR process
    • Used to raise and lower temperature of DNA to perform PCR
    • Enzymes isolated from the thermophilic bacteria remain active at the evevated temperatures used in PCR.
  8. Name/describe three basic steps of PCR technique
    • 1. Denaturation: heat targets DNA and it seperates into two strands. Then it is cooled.
    • 2. Priming: Primers are added that favors binding to complementary strand of test DNA. This prepares two DNA strands called amplicons for synthesis.
    • 3. Extension: DNA polymerase and raw materials in form of nucleotides are added and two complete strands are produced.
  9. What is the purpose of recombinant DNA technology?
    • Deliberately remove genetic material from one organism and combine it with that of a different organism.
    • To form genetic clones.
  10. What are THREE qualities every cloning vector must have?
    • 1. An origin of replication (ORI) this is needed somewhere on the vector so that it will be replicated by the DNA polymerase of the cloning host.
    • 2. Vector must accept DNA of desired size.
    • 3. Vectores typically contain a gene that confers druge resistance to their cloning host.
  11. What are the desireable quailites a cloning host must have?
    • Fast growth rate
    • Grown in large quantities using ordinary culture methods
    • Genome that is well mapped
    • Nonpathogenic
    • Capable of accepting plasmid or bacteriophage vectors
    • Maintains foreign genes through multiple generations