Diffusion, Osmosis, Tonicity Flashcards
What is diffusion?
the movement of molecules from a high concentration to low concentration
Criteria for diffusion to occur
- a concentration gradient exists between the intracellular and extracellular compartments
- the plasma membrane is permeable to the solute
What is the difference between passive and active transport?
Active transport requires energy while passive transport does not
What is a solute?
Any substance dissolved in a solvent
What is a solvent?
dissolving agent (water)
What is osmosis?
the movement of water from a an area of high concentration of water to low concentration of water
What is facilitated diffusion?
movement of molecules from a high to love concentration that involves helpers such as carriers or channel proteins
What does it mean for a membrane to be permeable?
it refers to the ease of transport across a membrane
What is osmotic pressure and how is it generated?
the ability to pull water from the other side of the membrane
concentration X particles
What is an osmotically active solute?
non-penetrating solutes are osmotically active
What is a hypertonic, hypotonic and isotonic solutions?
Hypertonic: higher solute concentration
Hypotonic: lower solute concentration
Isotonic: equal solutes
What happens to cells when they are place in hypertonic, hypotonic and isotonic solutions?
Hypertonic: water moves out of the cell (cell shriveling)
Hypotonic: water moves into the cell (cell swelling or lysis)
Isotonic: no change
