Bio Exam 2

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Bio Exam 2
2014-03-11 22:48:00
Bio 151

Bio 151
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  1. Operon

    Set of genes transcribed together
  2. Transcription Factor
    Proteins that bind to DNA
  3. Basal Transcription Factors
    Needed for all transcription

    • Bind to promoter
    • (sequence of DNA that RNApolymerase binds to begin transcription)
  4. Activator
    Transcription factors that signal for transcription to begin
  5. Enhancer
    Part of DNA that activator binds to
  6. Repressor
    Protein that stops/inhibits transcription
  7. Chromatin
    DNA wrapped around histones
  8. Heterochromatin
    DNA tightly wrapped around histones

    No transcription
  9. Euchromatin
    DNA loosely wrapped around histones

  10. Histone
    Protein that DNA wraps around

    8 histones = 1 nucleosome
  11. Chromatin Packaging
    Process of wrapping DAN around histones
  12. Acetylation
    Loosens DNA around histones
  13. Barr Body
    • Inactive x chromosome in body
    • Heterochromatin so not transcribed
  14. Ribosome
    • E site
    • -Exit of tRNA

    • P site
    • -Holds the growing peptide

    • A site
    • -tRNA recognizes mRNA and peptide bond is made
  15. Silent Mutation
    Change in single nucleotide but get same AA

    No effect on phenotype
  16. Missense Mutation
    • Change in nucleotide and get different AA 
    • - Change in primary structure of protein

    Can be beneficial, deleterious, or neutral
  17. Nonsense Mutation
    Results in stop codon - shortened polypeptide (primary structure)

    usually deleterious
  18. Frameshift Mutation
    • Addition or deletion of nucleotide that CHANGES THE FRAME
    • -Almost always deleterious
    • -Meaning of all subsequent codons altered
    • -NO FRAMESHIFT if 3 nucleotides added
  19. Insertion/Deletion Mutation
    • Insertion or deletion of nucleotides
    • Doesn't necessarily result in frameshift
  20. Exocytosis
    Secretion of intracellular molecules contained within membrane bound vesicles, to the outside of the cell by fusion of vesicles to the plasma membrane
  21. Endocytosis
    Pinching off of the plasma membrane that results in the uptake of a material from outside of the cell
  22. Protein Trafficking Steps (path of protein through a cell)
    • 1. Proteins are translated in the ER
    • 2. Proteins processed in the ER
    • 3. Go to Golgi in vesicles
    • 4. Further processed in Golgi
    • 5. Packaged in vesicles and go to plasma membrane
  23. Gene expression in eukaryotes
    • Nucleus
    • 1. RNA polymerase binds to DNA and transcribes mRNA
    • 2. mRNA processed in nucleus
    •    - Splicing -Introns cut out of pre-mRNA
    •    - 5' cap added, 3' tail added
    • 3. mRNA leaves nucleus
    • 4. Ribosomes attach and translate protein

  24. Gene expression in prokaryotes
    • 1. Sigma binds to DNA and transcribes mRNA
    • 2. Translation happens simultaneously by ribosomes

    polycystronic mRNA
  25. Transcriptional Control
    • Controls whether transcription happens (DNA to RNA)
    • -Preserves the most resources
    • -e.g. TF's, Pos and neg regulation, etc.
  26. Translational Control
    • Controls whether translation happens (RNA to protein)
    • -Ribosome, mRNA, tRNA, AA's present, etc.
  27. Post-Translational Control
    • Controls protein
    • -Fastest response time
    • -Posphatases, kinases, ubiquitination, etc.
  28. Primary structure of protein
    Polypeptide chain
  29. Secondary Structure of protein
    Alpha helices and beta sheets
  30. Tertiary structure of protein
    Folded secondary structure - functional
  31. Quaternary structure of protein
    Multiple tertiary structures bound together
  32. Peptide bond
    formed by condensation rxn between 2 amino acids
  33. Condensation rxn
    • Water is product
    • Monomers to polymers
  34. Hydrolysis rxn
    • Water is reactant
    • Polymers to monomers
  35. Amphipathic, Hydrophobic, Hydrophillic
    Determined by R group
  36. N-terminus
    • gets translated first, comes out first
    • 5' end
  37. C-terminus
    3' end
  38. Chaperones
    • Help proteins fold
    • Hides hydrophobic patches from cytosol
  39. Monomer
    Amino Acid
  40. Chromatin
    Multiple nucleosomes