Human Physiology Introduction

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Human Physiology Introduction
2011-02-18 14:26:25
water amphipathic micelles lipid bilayer polar dipole homeostasis

Human Phys flashcards for exam 1
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  1. What are the 3 necessities for homeostatic control?
    1) some way to measure the regulated variable

    2) some way to alter (effect) the regulated variable

    3) a way of linking measurement and regulation
  2. Why are there few examples of "natural" positive feedback ?
    Positive feedback is difficult to regulate until some massive event occurs

    (i.e. - oxytocin in childbirth or luetinizing hormone during ovulation)
  3. Special property of water:

    #1 - Water is a __________
    Water is a DIPOLE

    Polarity makes water a good solvent for ions
  4. Special property of water:

    #2 - Bonds btw adjacent water molecules are _______ and _________ .
    Bonds btw adjacent water molecules are LABILE and TRANSIENT.

    Bonds are made and broken in a fraction of a second and these loose bonds give water unusually high surface tension and cohesiveness.
  5. Special property of water:

    #3 - Water is a great solvent for _____.
    • Water is a great solvent for IONS.
    • (i.e. - NaCl)

    *remember "like dissolves like"
  6. Special property of water:

    #4 - _________ dissolving
    SELECTIVE dissolving

    • Water dissolves certain organomolecules that do not dissociate into ions but do have polar properties.
    • (i.e. - alcohols, sugars, hormones)
  7. Special property of water:

    #5 - High ____ capacity.
    High HEAT capacity

    This means water is difficult to heat and, since the body is mostly water, body temp remains relatively constant.
  8. Special property of water:

    #6 - High latent heat of _________.
    High latent heat of EVAPORATION

    It takes a lot of energy to heat liquid water into vapor. This is why we sweat to lose heat and cool down.
  9. Special property of water:

    #7 - Relatively __________ .

    When a force is applied to it, it exerts nearly the same force.

    This makes blood pressure possible.
  10. What are amphipathic compounds?
    Compounds containing both polar and non-polar groups or regions.
  11. Name two compounds that do not usually dissolve in water
    Lipids and steroids
  12. The cell membrane has low permeability to ______ substances like ________ and greater permeability to_______ substances like _________.
    The cell membrane has low permeability to POLAR substances like IONS, SUGARS, INSULIN and greater permeability to NON-POLAR substances like STEROID HORMONES, CO2 , O2
  13. Give an example of an amphipathic molecule
    Phospholipids have a charged head and two uncharged tails making them amphipathic.

    • O <--charged head
    • l l
    • l l <--uncharged tails
  14. What are sphingolipids?
    A type of lipid found in cellular menbranes and mostly in the brain
  15. List the three primary types of lipids in cellular membranes
    1) Phosphoglycerides - have glycerol backbone

    2) Sphingolipids - have sphingosine backbone

    3) Sterols - nonpolar, slightly water soluble (i.e. cholesterol)
  16. Cell membranes contain both _____ and __________.
    Cell membranes contain both LIPIDS and PROTEINS
  17. What are the two types of proteins found in the cell membrane?
    Peripheral - associated with the surface of the membrane (i.e. G-protein)

    Integral - span the membrane
  18. Integral proteins serve as

    1) Passive transport pore and channels

    2) Active transport pumps (Na/K pump)

    3) Membrane lined enzymes

    4) Receptors
  19. Describe homeostatis...
    Maintenance of relatively constant conditions within the internal environment of the body
    The response of a system goes in the opposite direction of the changes that it set in motion.

    The response of a system goes in the same direction of the changes that it set in motion.
  22. Describe the cell membrane
    A barrier separating a cell from ECF consisting of phospholipids, proteins, and cholesterols.
  23. Define micelle
    A sphere formed by a single layer of phospholipids with the polar region facing the aqueous environment and the nonpolar regions facing inward.
  24. The 4 types of integral proteins are
    • 1) Passive transport pores and channels
    • 2) Active transport pumps
    • 3) Membrane lined enzymes
    • 4)Receptors
  25. Define phospholipid/phosphoglyceride
    Fats with a glycerol backbone containing a phosphorous group
  26. Explain how and why the cell membrane is fluid
    Molecules within the membrane exchange places with adjacent molecules 107 times per second, but rarely change with molecules from the other side of the bilayer. Fluidity is important for receptor function and placement.