CELL MEMBRANES

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CELL MEMBRANES

• Review for Lecture P051

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most important concept All cells have

• chromosomes,
• ribosomes,
• some type of energy-conversion system,
• and phospholipid membranes with protein channels
  and enzymes.

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Cnxns to chem
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most important concept about
membranesPHOSPHOLIPIDS

• What is the main function of the cell membrane?
• How does the structure of phospholipids help
  explain how cell membranes do their job?

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• Which part is hydrophobic?

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Amphipathic phospholipid
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Cholesterol is also amphipathic but smaller.
Why? later
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Test 1 Explain why phospholipids form a
bilayer.
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Test 1 Draw a bilayer .
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Permeability be able to explain
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test 1 Explain why cell membranes need
unsaturated fats and cholesterol
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More pictures

• http//info.bio.cmu.edu/Courses/BiochemMols/BuildB
  locks/BBlocks.html
• http//www.bio.cmu.edu/Courses/BiochemMols/BuildBl
  ocks/Membrane.html
• http//www.queens.edu/faculty/jannr/molecular/inde
  x.htm
• http//www.queens.edu/faculty/jannr/cells/index.ht
  m

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Fluid mosaic hypothesis

• Fluid lipid bilayer.
• Mosaic protein floating in the bilayer
• vs older sandwich models outer layers of
  protein (rejected)
• you cant see a membrane (its too small you
  only see a border with a light microscope)
• circumstantial evidence from electron microscopes

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• Which hypothesis do these data support?
• Fluid mosaic
• OR
• Sandwich

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http//campus.queens.edu/faculty/jannr/cells/cellt
ables.doc
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THE MAIN CELL TOOLS
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most important concept All cells have

• chromosomes,
• ribosomes,
• some type of energy-conversion system,
• and phospholipid membranes with protein channels
  and enzymes.

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LAB this week

• Easy, learning skills for next experiment
• Turn in special chart (download LAB 3)
• Use lab resources to prepare for Test 1
• flash cards
• ask assistants and professor questions
• use lab computers to review

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BASIC BIOCHEMISTRY

• Quiz 4. You MUST know these categories
• for Test 1.
• For understanding membranes and other cell parts
• for understanding genetics coming after test 1
• For reading newspapers
• for making personal decisions for health wealth

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Experiment summaries

• Logical consistency
• hypothesis cause
• experiment measure
• results of measurements
• conclusion logical consistency

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Cnxns to chem
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Cell types
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most important concept All cells have

• chromosomes,
• ribosomes,
• some type of energy-conversion system,
• and phospholipid membranes with protein channels
  and enzymes.

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Prokaryotes

• http//campus.queens.edu/faculty/jannr/cells/cellt
  ables.doc

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PROKARYOTES

• Oldest
• smallest
• membraneoutside
• wall alsousually
• but no...

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