Cell Bio 1 part 2

  1. How many genes are in human DNA
  2. how many base pairs are in DNA
    3.5 bil
  3. how many chromosomes in the human DNA
    26 chromosomes
  4. width of a DNA strand
    2 nm
  5. space between each base
    0.34 nm
  6. how long is all the DNA in the cell
    1 meter
  7. how many cells in the body
    10-100 trillion
  8. how large is a eukary nucleus
    10-20 microns
  9. how large is a eukary cell
    50-400 microns
  10. how long is a chromosome
    1- microns
  11. Chromatin
    • material that contains DNA
    • mixture of DNA and protein
    • 50:50 mixture
  12. type of chromatin
    • euchromatin
    • heterochromatin
  13. euchromatin
    • lightly packed DNA with lower density of genes
    • light by EM
    • ~10% genes
    • ~1% coding genes
  14. heterochromatin
    • non-coding repetitive elements, structural elements
    • ~50% of genome is repetitive sequences
    • dark by EM
    • heavily packed
  15. projuria
    caused by Lamin-A changes gene expression due to structural problem in the nucleus
  16. types of protein in chromatin
    histones, DNA polymerase, and all regulatory machinery
  17. nucleosome
    the 1st level of organization of a chromatin
  18. how many base pairs in a nucleosome
  19. structure of nucleosome
    8 histones 4 different types of histones
  20. KASH
    integral membrane protein that binds to the cytoskeleton and SUNS
  21. SUN
    integral membrane protein that binds the lamens and KASH
  22. Lamens
    intermediate filament
  23. what happens to lamens during mitosis
    the lamen proteins are phsophorylated and break down
  24. what does histone H1 do
    it makes the DNA with nucleosomes coil and coil until a solenoid is formed but that has not been completely proven
  25. RNA polymerase error rate
    • 1/1000 bp, not that big of a deal
    • mutation would be innocuous
  26. stemloop vs. hairpin
    • hairpin-5-10 bp and loop
    • stem loom - 100-700 bp and then a loop
  27. what direction does RNA polymerase read and what is the strand
    3' to 5' end of the non-coding, template, antisense, transcribed strand
  28. what is the 5' to 3' strand named
    coding strand, sense strand
  29. details about transcription
    • only small fraction of genome is ever transcribed (~5%)
    • happens during most of cell cycle (not M phase)
    • Product is ssRNA
    • no primer required
  30. types of RNA Poly
    • Pol I - make ribosomal RNAs
    • Pol II- make mRNA and microRNAs and some snRNAs
    • Pol III - make tRNAs and snRNAs (regulatory RNAs)
  31. parts of a gene
    promoter, UTR transcribed region UTR
  32. parts of the promoter
    • UTR, transcribed region and another UTR
    • core promotor w/ TATA box (-25 position)
  33. how long is the promotor
    50-200 bp long
  34. percentage of exons and introns in gene
    90% introns, 10% exons
  35. terminator sequence
    polyadenylation sequence that forms a secondary structure which causes the RNA pol to slow/stop
  36. how fast does RNA pol work
    30-50 bp/ second
  37. Transcription Initiation steps
    • TF2 D binds TATA box- creates kink
    • recruits TF2 A, B, F
    • Pol II recruited
    • TFII E, H recruited
    • TFII H helicase activity and kinase
    • phosphorylated pol II starts transcription
  38. Transcription Elongation steps
    • 3' OH of last nucleotide forms phosphodiesterbond
    • as RNA is processed, salts and proteins bind to new RNA
    • RNApolII binds pretty tightly low k-
  39. Transcription termination
    pol II slows/stops, triggers dissociation
  40. general structure of specific TF
    DNA binding domain, +- regulatory domain (switch), and activation domain (bind activator proteins)
  41. activator proteins
    • HATs - adds acetyl to positive lysine residues to weaken interaction of DNA and histone
    • NRCs- remove histones from DNA
  42. HATs
    • histone acteyl transeferases
    • N terminal tail have lysine residues
    • adds acetyl to lysine residue and removes + charge from histone
    • weakens DNA association
  43. NRC
    • nucleosome remodeling complex
    • use ATP to move along DNA and remove histones
    • when combined with HATs its more efficient
  44. corticosteroid
    • lipid hormone
    • excell signal that transfers into cytoplasm and binds to a regulation domain and is activated¬†
    • transported to the nucleus and effects transcription
    • causes increase metabolism and hunger
Card Set
Cell Bio 1 part 2