L312/Spring 2007Lecture 2Drummond

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L312/Spring 2007 Lecture 2 Drummond

• Please bring one 4x6 card to class each day.
  Ill have extras in case you forget.
• 2. Ill post the drawing exercise, due Tuesday,
  on the website today.
• Ill update the website to include an office hour
  for Andrian and Eric
• Todays learning objectives
• a. Cells as an independent unit
• b. Microscopes as a tool for studying
  intracellular structures
• c. Membranes and filaments as organizing
  structures
• Think about scale!!!
• To read Ch. 1, (Ch. 4 pp. 160-166 may get to
  next time)
• Other notes please read Chapter 1 (focus on
  elements covered in lecture)
• Todays web resources SEM http//www.mos.org/sl
  n/sem/intro.html
• TEM http//nobelprize.org/physics/educational/mic
  roscopes/tem/
• CON http//www.physics.emory.edu/weeks/confocal/
• http//courses.bio.indiana.edu/L312-Drummond/home.
  html

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For these features, note subject, scale and
context where do shapes come from? How do
materials move?
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A eukaryotic cell--what are elements to focus on?
What organizes these structural features of the
cell?
Always ask What is the size scale? What kind of
microscope was used What was done to let you
see The image?
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Intracellular membranes are essential--where are
they found?
How could you Get this 3D view?
What is the value of enclosed Intracellular
spaces? How are these connected to the rest of
the cell?
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What does the nuclear envelope enclose?
Single viewing plane?
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What is the purpose of the nuclear envelope?
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What does the endoplasmic reticulum (ER) do?
What are the blobs? Why is there a
membrane-enclosed space? What is the relationship
between the ER and the nuclear envelope?
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What does the Golgi apparatus do?
What are the blobs? What is the relationship with
the ER?
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A summary of membrane-enclosed spaces
Try to build a model that explains how molecules
move Throughout the cell via the
membrane-enclosed spaces. Track information
from the DNA to the final target site.
Haunting question What holds membranes in
place?
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What are key roles for filamentous elements in
the cell?
Actin microtubules intermediate
filaments
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Microtubules as catalysts for intracellular
movement
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Features of light and fluorescence microscopy
LIVING specimens OK here--why?
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Visible images Fluorescent images
But how do you get clear, in-focus planes and not
blobs?
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Confocal image of a drosophila embryo
conventional
confocal
Fluorescence microscope stained for actin
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Note Conditions!!!
Note Conditions!!!
Be able to distinguish TEM from SEM, and know
when to use each.
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What determines the resolution of each technique?