Cell labb flashcards.txt

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Cell labb flashcards.txt
2011-12-13 17:44:27
Cell biology practice

Cell biology practice - Questions
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  1. • Which cells can be a source of DNA of certain gene?
    All cells with a nucleus.
  2. • Which cell can be a source of mRNA of certain gene?
    Any cell which expresses that gene (synthesizes proteins from that gene.)
  3. • What kinds of steps are in DNA isolation?
    Cell lysis | Deproteination (removal of proteins) | (protease, absorption or extraction) | DNA precipitation by ethanol | DNA dilution in water or buffer
  4. • Which methods are used for DNA isolation?
    Phenol-chloroform extraction (different solubility conditions in solvents) | Salting out method (protein precipitation by NaCl) | Absorption method (silica-gel membrane)
  5. • Which method is RNA detected by?
    Northern blot. (side note; DNA detected by Southern blot.)
  6. • How is measured a concentration of nucleic acids?
    Spectrophotometry (absorbance maximum for nucleic acids 260 nm for proteins 280 nm)
  7. • To which charge does DNA move towards in electrophoresis?
    Positive, since DNA is negative itself.
  8. • For which purpose is used gel electrophoresis?
    To distinguish fragments of different sizes.
  9. • Why is DNA seen in agarose gel?
    Ethidium bromide is used as a dye for DNA (and RNA) and fluoresces under UV light.
  10. • According to which constant does DNA migrate in gel electrophoresis?
    Size of the DNA molecule or negative-to-positive migration???
  11. • To which charge does DNA migrate in gel electrophoresis?
    From negative to positive.
  12. • What is it PCR?
    Polymerase chain reation is a method to amplify DNA exponentially. Amplifies selected DNA sequences. DNA polymerase is used to replicate DNA by in vitro enzymatic replication.
  13. • What is a mechanism of PCR machine?
    A thermal cycler raises and lowers the temperature of the PCR samples in pre- programmed steps.
  14. • Which 3 basic steps does one PCR cycle contain?
    Denaturation, annealing, elongation (extension is the word used by Prof.Cerna)
  15. • Which 3 basic components are added to PCR reaction?
    DNA polymerase (Taq polymerase,) primers (forward & reverse,) and nucleotides. Also dNTPs???
  16. • Which basic 4 components do you add to PCR reaction?
    DNA strand, Primers, DNA Taq polymerase, dNTPs (Buffer + Cations(mg+))
  17. • What is a mathematical formula of amplification run?
    2 to the "n"th power = number of copies of wanted DNA region [where "n"=number of cycles]
  18. • What is it hybridization?
    It is the method used to detect the sequence of nucleotides of a DNA strand. It involves the denaturation of a DNA molecule, and the complementary binding of a "nucleic acid probe" to the original DNA strand (annealing.)
  19. • What is it RFLP?
    Restriction fragment length polymorphisms, or "riflips," are the differences in DNA sequence on homologous chromosomes that result in different patterns of restriction fragment lengths (restriction fragments=DNA segments resulting from treatment with restriction enzymes) useful as genetic markers. The restriction fragments are then seperated according to length by agarose gel electrophoresis.
  20. • What is RFLP based upon?
    Cut DNA into restriction fragments using suitable endonucleases.
  21. • Which basic component is added to PCR product during RFLP?
    Endonucleases (restriction enzyme)
  22. • What do enzymes DNA polymerases produce and where are they used?
    • cDNA
    • DNA polymerases add nucleotides to an existing chain. The result is a complementary strand. Heat stable DNA polymerases such as Taq polymerase are used in PCR.
  23. • What do restriction enzymes produce and where are they used?
    Restriction enzymes (restriction endonuclease) produce restriction fragments. They are used in RFLP. They cut dsDNA at the sugar-phosphate backbone, leaving the nitrogenous base pairs (mostly) intact. They may however leave "sticky ends" consisting of a few bases without their complementary bases.
  24. • What is a source of enzymes used in molecular biology?
    Enzyme bank????
  25. • By which method is a complete gene analysis performed and its mechanism?
  26. • What is the method of finding unknown mutation in a gene?
  27. • Which 3 methods are used for detecting on KNOWN mutation in a gene?
    • PCR with allele specific primers (CFTR delta F508)
    • PCR and RFLP (HFE C282Y)
    • DNA hybridization with DNA probes
  28. • What type of herebility is in disease cystic fibrose and hemachromostosis?
    Autosomal recessive
  29. • What is the frequent mutation in cystic fibrose?
    CFTR delta F508
  30. • What is the frequent mutation in hemachromostasis?
  31. • Which organs are impaired in c.f?
    Lungs and digestive system.
  32. • Which organs are impaired im hemachromostasis?
    Liver, heart and pancreas
  33. • What is it genomics and on what kind of method is it based?
    Genomics is the study of an organism's entire genome.