which molecules can pass thru the lipid bilayer via simple diffusion (order)
can pass thru (hydrophobic)
-non polar molecules (O2,CO2,steroid, hormones)
only partially (hydrophilic)
-small uncharged polar molecules (water,ethanol)
then
-large uncharged polar molecules (amino acids,glucose)
cannot pass thru (hydrophilic ions)
-charged molecules
which would diffuse across a cell membrane most easily
small, uncharged, non polar molecules
water can form a ____charge around ions
hydration charge
where are the higher levels of Ca+ in the cell
higher outside cell (ECF)
where are the higher levels of H+ in the cell
higher inside cell (ICF)
where are the higher levels of K+ in the cell
higher inside the cell (ICF)
where are the higher levels of Na+ in the cell
higher outside the cell (ECF)
using the sodium potassium pump which way do Na and K move
3 Na+ out
2 K+ in
what are the charges inside vs outside the cell and which way do molecules want to move
(-) inside
(+) outside
- want to move from (+) to (-)
what is passive transport and the two types
- no ATP required
- moves along concentration gradient
2 types:
simple diffusion & facilitated diffusion
what is simple diffusion
- no proteins
- no ATP
- conc gradient
what are the two types of facilitated diffusion
transporters & channel proteins
describe transporter facilitated diffusion
- binds solute one side of the membrane and changes conformation to transport solute to other side of membrane (specific shape to accept)
- slower rate than channel
- specifically glucose transporters
- can move in either direction
describe channel facilitated diffusion
- usually transport of ions
- gated / ungated
what are the types of gated channel facilitated diffusion
- voltage gated (energy/ voltage)
- mechanically gated (pressure/touch)
- ligand gated (neurotransmitters)
what is active transport and the 3 types
ATP is required
-secondary
-primary
-light driven
describe light driven active transport
bacteriorhodopsin-proton pump
describe primary active transport with an example
ex. Na+/K+ pump
- 3 Na out and 2 K into cell
- both are moving AGAINST concentration gradient
- energy is needed for this by direct ATP hydrolysis
in many cells Na/K pump generates the ________
resting membrane potential
describe secondary active transport
- coupled transport of two solutes! (symport & antiport)
- has a driving ion used to drive uphill transport of a second solute
- uses an already established gradient
what is symport vs antiport
symport - both going same ways
antiport - going opposite ways
how specifically in secondary active transport is there transport of two solutes
-ATP powered pump transports one solute to build up the electrochemical gradient
- this gradient drives transport of second solute via a !different! channel or transporter
3 types of transporters involved in transport of glucose
- Na/K pump
- Na driven glucose symport
- passive glucose transporter
ion channels have ___ diversity
lots of
