Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/10

Click to flip

10 Cards in this Set

  • Front
  • Back
Selective Permeability
In Cell membranes, biological feature that allows some substances to pass through membrane quicker than others.

Yes: small hydrophobic molecules: O2, H2o, CO2.
No: Larger molecules & ions.
Diffusion
Tendency of molecules to spread out into available space.
Any substance will diffuse down concentration gradient spontaneously, reducing free energy.

Results from intrinsic kinetic energy (thermal motion).

http://www.indiana.edu/~phys215/lecture/lecnotes/lecgraphics/diffusion.gif
Osmosis
Diffusion of water across selectively permeable membrane (a special case of passive transport).
Depends on total solute concentration

Not to be confused with “Ozzmosis”, the Ozzy Osbourne album…
Hypertonic
Solution with higher concentration of solutes
Hypotonic
Solution with lower concentration of solutes.
More unbound water molecules letting them move across membrane.
Osmoregulation & Paramecium
Paramecium doesn’t explode because it lives in hypotonic pond water that constantly enters cell, but is offset by osmoregulation.
Osmoregulation
Cell membrane is less permeable to water.
Contractile vacuole works to ‘bail out’ cell.
Exocytosis
Removal of waste or secretory proteins from cells.
Endocytosis
Cells take in macromolecules & particulates by forming new vesicles.
Cell cycle
Mitosis & Cytokinesis.