Biology; Osmosis

Midterm Study set

Osmosis

diffusion of water across a membrane

Solvent

usually water, dissolves solute

Solute

dissolves in solvent

Effects of solute on osmosis

-water binds to solute: solutes lower concentration of water
-solute cannot always cross the membrane: water will move instead

Hypertonic

environment is more concentrated

Hypotonic

cell is more concentrated

Isotonic

equal concentration

Hypotonic

-animal cell: lyse (rupture)
-plant cell: turgid (healthy, full of water)

Isotonic

-animal cell: functions normally
-plant cell: flaccid (water depleted)

Hypertonic

-animal cell: shrivel
-plant cell: plasmolyzed

Active transport

maintains homeostasis

Passive transport

-maintains equilibrium NOT homeostasis
-requires energy to be maintained

Sodium potassium pump

-3 Na+ outside
-2 K inside
-keeps inside of cell negative or at least less positive

Membrane potential

difference in charge between a cell and its environment (keep different)

Da Cell

-Sodium "Na"
-Potassium "K"