Exam 1

• Membrane transport


  How molecules move in and out of the cell
• Membrane transport


  Cells move in and out of the cell through simple diffusion, facilitated diffusion, osmosis, and active transport
• Fick's law


  Explains diffusion across a concentration gradient
• Passive transport


  • Doesn't require ATP energy
  • Uses concentration gradient as energy source
  • Moves from [high] → [low]
• Simple diffusion


  Molecule goes through lipid bilayer

  
• Facilitated diffusion


  Mediated transport requires a membrane protein
• Higher temperature

  Increases rate of diffusion
• Bigger surface area


  Increases rate of diffusion
• Bigger molecular size and weight


  Decreases diffusion
• Thicker membrane


  Decreases rate of diffusion
• Diffusion stops when there's an equilibrium of material
• Channels


  • Create a water filled pore
  • No binding sites
  • No saturation
  • Transmembrane proteins
  • Majority are ion channels
  • Gated (voltage, mechanically, ligand gated)
• Carriers


  • Never form an open channel between the two sides of the membrane
  • Also transmembrane proteins
  • No direct connections with EFC and ICF
  • Slower than channels
  • Facilitated diffusion carriers are not pumps
  • Have specificity
  • Affected by temp, pH
• Active transport


  • Requires energy
  • ATP
  • [low] → [high]
  • Active transporter
  • ATPases
  • Pumps
  • Works against concentration gradient
• 1st active transport


  1. Directly uses energy

  2. Na/K pump moves 3Na+ out and 2K+ in

  3. Mediated transport

  4. Specificity

  5. Competition

  6. Saturation
• 2nd active transport


  1. Uses electrochemical gradient

  2. Na/Glu symporter moves Na+ and glucose into cells

  3. Glucose is transported up its concentration gradient

  4. Na+ diffuses down its concentration gradient

  5. Symport = cotransport

  6. Antiport = countertransport
• Vesicular transport


  Assisted transport of larger molecules
• Osmolarity


  Total concentration of solute particles
• Body fluid compartments


  • ECF = 1/3
  • Plasma = 1/4 of ECF
  • ICF = 2/3
• Molarity


  Mol x dissociation factor / L
• Water goes from low solute to high solute
• Normal osmolarity of body fluids

  300 mOsm
• Range of osmolarity


  250-350 mOsm
• Types of particles


  • Non-penetrating
  • Penetrating
• Non-penetrating


  • Completely no penetration
  • Functionally non-penetrating
• Non-penetrating

  • Protein is too big
  • NaCl
• Penetrating


  Freely penetrating
• Penetrating

  • Urea, cholesterol, glucose
• Inulin


  A complex carbohydrate = ECF
• Tonicity


  How a solution affects cell volume
• Tonicity effects


  • Cells in isotonic solution stay the same
  • Cells in hypertonic solution shrink
  • Cells in hypotonic solution swell
• Standard IV solutions


  • Normal saline (0.9% NaCl)
  • D-5-W (5% dextrose in water)
  • 1/2 normal saline (0.45% NaCl)
  • D-5-Normal Saline (5% dextrose in normal saline)
  • D-5-1/2 NS
• Normal saline


  Isosmotic, Isotonic
• 1. 5-W


  Isosmotic, Hypotonic
• 1/2 normal saline


  Hyposmotic, Hypotonic
• 1. 5-Normal Saline

  Hyperosmotic, Isotonic
• 1. 5-1/2 NS

  Hyperosmotic, Hypotonic
• Homeostasis


  Maintains stable internal conditions
• Cannon's postulates


  • Describe regulation of homeostasis
• Cannon's postulates


  • Role of autonomic nervous system in homeostasis
  • Tonic activity
  • Antagonistic control
  • Effects of chemical signals based on receptors