BIOL41 Lecture Exam2 -1

Card Set Information

BIOL41 Lecture Exam2 -1
2012-11-15 06:02:34

BIOL41 Lecture Exam2 (1) Metabolism,Genetics,Biotech
Show Answers:

  1. In general, what's the scheme for the catabolism of any
    organic molecule (whether fat, protein or carbohydrate)?
    all catabolized to end up as Krebs cycle/metabolic precursors
  2. carbohydrate catabolism
     polysaccharides broken down outside of cell by exoenzymes -> mono/disaccharides transported into cell -> glycolytic intermediate
  3. lipid catabolism
    tri/diglycerides broken down outside of cell by secreted lipases -> FFAs, glycerol transported into cells -> B-oxidation -> acetyl-CoA/glycerol to glycolytic pathway
  4. protein catabolism
    protein in environment broken down by enzymes -> amino acids transported into cell -> conversion into metabolic intermediates
  5. most common form of carbohydrates in nature
  6. common source of lipids
  7. chromosome
    organized structure of DNA and protein
  8. genome
    • entirety of an organism's hereditary information
    • includes both the genes and the non-coding sequences of the DNA/RNA
  9. How is prokaryotic DNA organized?
    • circular
    • double stranded
    • typically only 1 chromosome
  10. How is eukaryotic DNA organized?
    • linear
    • double stranded
    • several chromosomes
  11. enzyme responsible for DNA synthesis
    DNA polymerase
  12. unwinds DNA
  13. semiconservative replication
    each new double-helix has 1 older strand from the previous cell division and 1 newly synthesized strand
  14. plasmid
    • small, circular external, double-stranded DNA in prokaryotic cells
    • can give extra advantages to bacteria (ie: antibiotic resistance)
  15. gene
    • 1) unit of info to form protein
    • 2) physical location on chromosome
  16. gene expression
    process by which information from a gene is used in the synthesis of a functional gene product (protein, rRNA, tRNA)
  17. transcription
    yields an RNA product from the DNA
  18. enzyme responsible for transcription
    RNA polymerase
  19. template vs nontemplate strand
    • template is the strand that is actively being transcribed into RNA and will eventually be translated into protein
    • non-template strand is the strand of DNA which is not actively being transcribed/translated into protein
  20. how RNAP knows where to bind/begin transcription
    promoters present 35 or 10 nucleotides upstream of gene to be transcribed (where proteins assemble)
  21. Where does the process of transcription occur in prokaryotes?
  22. Where does the process of transcription occur in eukaryotes?
  23. intron
    any nucleotide sequence within a gene that is removed by RNA splicing while the final mature RNA product of a gene is being generated
  24. translation
    turns mRNA into protein
  25. mRNA
    • carries coding info for amino acids
    • sent out of nucleus to cytoplasm/ER
  26. codon
    section of mRNA with 3 nucleotides that code for specific amino acids
  27. stop codon
    • nonsense codons
    • UAG, UGA, UAA
    • where translation ceases
  28. tRNA
    • transfer RNA
    • stays as RNA, used as is
    • molecule that brings amino acid to ribosome
    • has anticodon complimentary to codon
  29. anticodon
    set of nucleotides complimentary to a codon
  30. ribosome
    • complex that brings codons and tRNA together to form amino acid chain for protein synthesis during translation
    • made of large and small subunits and several polypeptides
  31. kind of bond that joins amino acids
    peptide bonds
  32. polysome (polyribosome)
    many ribosomes read one mRNA simultaneously, progressing along the mRNA to synthesize the same protein
  33. 4 unique features of bacterial genetics
    • 1) single genome per cell (changes seen easier/quicker)
    • 2) fast growth rates
    • 3) enormous numbers of offspring
    • 4) easily sequenced
  34. auxotroph
    • "strange eater"
    • doesn't consume the same as a normal organism of its species
  35. genotype
    • gene (DNA) responsible for phenotype
    • single genotype change in haploid organisms = phenotype change
  36. phenotype
    • observed characteristic representative of genotype
    • need at least 2 mutations to change phe of diploid organisms
  37. missense mutation
    change in DNA -> change in amino acid translated
  38. nonsense mutation
    change in DNA leading to a stop codon 
  39. 3 ways nucleotide substitution can occur
    • 1) spontaneous error
    • 2) base analogs (ex: bromouracil incorporated instead of thymine, but base pairs with guanine)
    • 3) UV radiation (covalently bound thymine dimers caused)
  40. mutagen
    compound that causes mutations in DNA
  41. carcinogen
    compound that causes mutation in DNA that leads to cancer
  42. Mutations in which particular genes are more likely to result in cancer?
    • 1) oncogenes 
    • 2) tumor suppressors
  43. oncogenes
    • control when cell decides to divide
    • normally pushes a cell through DNA synthesis
  44. How do we initially test new products of mutagenicity?
    Ames test (look for mutation that changes phe)
  45. Ames test
    • 1) pour plates with his(-) media
    • 2) spread plate with his(-) Salmonella auxotroph (can't make His), add disk with test chemical in center
    • 3) POSITIVE result: mutated bacteria (only mutated bacteria can grow, bc chemical reversed original mutation) -> SUGGESTS SUSPECTED CHEMICAL IS MUTAGENIC
  46. recombination
    mixing of 2 types of DNA inside 1 cell
  47. homologous sequences
    similar sequences of DNA (often bc of same origin)
  48. horizontal gene transfer
    • sharing of genetic info from 1 cell (donor) to another (recipient)
    • rare
  49. vertical gene transfer
    sharing of genetic information from parent to progeny
  50. transformation
    • "naked" DNA in environment taken up by bacterial cell
    • -recombines or catabolizes for amino acids
  51. transduction
    • 1) bacteriophage injects DNA into bacteria then
    • 2) replicates but accidentally
    • 3) packages bacterial DNA and
    • 4) injects DNA into a similar bacterial cell leading to
    • 5) recombination of homologous DNA

    VIRUS is used to move bacterial DNA
  52. conjugation
    • very closely related cells pass DNA (F plasmid) through a pilus
    • must have 1 cell with ability to make pilus, and 1 cell without ability
  53. biotechnology
    use of living systems and organisms to develop or make useful products
  54. recombinant DNA technology
    use naturally occurring gene transfer features of microbes to study and manipulate genes
  55. 3 major goals for using recombinant DNA technology
    • 1) To eliminate undesirable phenotypic traits in humans, animals, plants, and microbes. 
    • 2) To combine beneficial traits of two or more organisms to create valuable new organisms, such as laboratory animals that mimic human susceptibility to HIV.
    • 3) To create organisms that synthesize products that humans need (vaccines, Ab's)
  56. recombinant plasmid
    • cloned gene
    • plasmid with gene of interest ligated into it
  57. restriction enzyme
    • cut DNA at specific sequences
    • enzymes naturally found in bacteria/fungi as defense mechanism
  58. DNA library
    collection of DNA fragments that is stored and propagated in a population of micro-organisms

    • 1) extract DNA
    • 2) cut DNA of interest and plasmid with RE's
    • 3) ligate digested fragments with digested plasmid
    • 4) transform and grow in bacteria
  59. PCR
    • polymerase chain reaction
    • uses DNA pol from thermophilic bacteria
    • makes many copies of a specified DNA sequence
    • useful for amplifying scarce DNA
  60. Southern blot
    detects gene in DNA

    • 1) DNA separated by agarose gel
    • 2) transferred to porous membrane
    • 3) probed with radioactive probes complimentary to sequence of interest
    • 4) probes expose photographic film if bound to DNA of interest
  61. DNA microarray
    • consists of molecules of single-stranded DNA, either genetic
    • DNA or cDNA, immobilized on glass slides, silicon chips, or nylon membranes
    • single strands of fluorescently labeled DNA in a sample
    • washed over an array adhere only to locations on the array
    • where there are complementary DNA sequences

    can be used to monitor gene expression, diagnose infection, ID organisms in an environmental sample