1.2 Cell physiology Flashcards
What molecules can easily go through membrane (passive diffusion?
Small, non polar molecules
O2, CO2
What is channel-mediated diffusion considered and what molecules would need this?
Facilitated diffusion and charged atoms
Na+, Ca2+, Cl-
Carrier mediated diffusion
Facilitated diffusion
Specific molecule induces a structural change
Typically used for larger molecules (like glucose and amino acids)
Put these in order from highest membrane permeability to lowest membrane permeability
(Large, uncharged polar molecules; small, non polar molecule; small, uncharged polar molecules; and ions)
Small non polar molecules; small uncharged polar molecules; large, uncharged polar molecules; ions
Anything that needs the help of a protein is…
Facilitated diffusion
What molecules can cause a gradient for osmosis to occur?
Any soluble molecule (ions, glucose, proteins)
How does water move across membranes in osmosis?
Both simple diffusion and facilitated diffusion (through aquaporins)
Hyper-osmotic means…
Solution with a greater concentration of water
Osmolarity
The # of particles contributed by a compound when it solubilizes
What two things does active transport require?
Membrane protein (facilitated) and energy!
Primary active transport
The pump itself is fueled by ATP (ex: sodium potassium pump)
Secondary active transport
Energy derived from one solute (Na+ ion) moving down its concentration gradient drives transport of another solute (glucose) across the membrane.
Symport
Secondary active transport, going in same direction
Antiport
Secondary active transport, going in opposite directions
Saturation of facilitated transporters can occur in..
Any mode of facilitated transport (passive and active) that involves a specialized (specific) carrier or channel protein
