neuroscience 3

  1. How do organisms multicellular organism function and look?
    • In multi cellular organism different celltypes look + function very different.
    • -contain same DNA
    • -gene expression differs
    • different celltypes
    • make different sets of proteins
  2. Which steps can be regulated in DNA?
    All steps from DNA
  3. For most genes, which step is most important?
    First step is most important.
  4. What happen to daily Rhythms?
    Most physiological +biochemical processes in body rise+fall in daily rhythms.
  5. Internal body clock in humans runs on how many hours?
  6. SCN
    Supracliasmatic Nucleus
  7. SCN located in ?
    In center of brain, above optic chiasm
  8. Which class of cells in retina detect daylight and for photopigment?
    Ganglion cells and melanopsin
  9. light sensitive depents on?
    light-sensitive themselves, don not depend on rods +cones and axons to SCN
  10. Output is from
    SCN to Pineal Gland
  11. Pineal gland releases?
    • -Pineal gland releases melatonin into blood stream
    • -melatonin inhibited by light
    • -peaks between 2 am and 4 am
  12. Negative feed back controls
    expression of clock genes
  13. SCN neuron
    • -Each single SCN neuron is a small clock
    • -keep their rhythm even in tissue culture
    • -expression of clock genes vary w/ period of 24 hrs
  14. Circadian clock in Drosophila Fruit fly
    • Transcription of Tim/per genes in nucleus
    • -MRNAs to cytosol
    • -translation: MRNA -Protein
    • -Heterodimer formation -Tim prot + perProt.
    • -Tim/per Proteins transported to nucleus
    • -per protein inhibits transcription of Tim/per genes
    • -less MRNA ,less protein made
    • -Inhibition of transcrioption removed
    • and process goes over and take 24 hrs.
  15. Mechanism for reseting clock
    Tim protein degradation in response to light
Card Set
neuroscience 3