Cellular Transport Flashcards
intracellular
materials inside the cell
extracellular
outside the cell
bilayer cell membrane
contains two layers of phospholipids
fluid mosaic model
membrane contains phospholipids, cholesterol, proteins, and carbs
selective permeability
only certain substances can pass in or out of the cell
the route of transport depends on the size, shape, and charge of substance
Passive Membrane Transport
does not require the cell to expend energy
diffusion, osmosis, and facilitated diffusion
Active Membrane Transport
requires the cell to expend energy in the form of ATP
active transport, secondary active transport, endocytosis, exocytosis
moving against the concentration gradient
Diffusion
substances move down a concentration gradient (from high to low)
lipid soluble substances (ex. oxygen, CO2, and steroids) diffuse directly through phospholipid bilayer
Osmosis
the diffusion of water
osmotic pressure is the force required to prevent the movement of water across the membrane
Hypotonic
less solute than in the cell
Water moves into the cell
lysis
Isotonic
equal solute in solution and cell
no change
Hypertonic
more solute than inside the cell
water exits the cell
crenation
Facilitated diffusion
carrier mediated transport process
higher concentration to lower concentration (no ATP required)
leak channels
constantly allow ions to pass
gated channels
limit the movement of ions by opening and closing
