Physio-B1 Mem. Transporters

Front 1

carrier type mechanism transport

Back 1

- bind a specific substrate
- release by conformational change
- slower than channel type b/c time need to release
- "alternating access" model/binding site

Front 2

selective channel type mechanism transport

Back 2

-exist only for ions and water
b/c they are small

-ion selecting channels

Front 3

non-selective transporter type mechanism transport

Back 3

-contain large pores that allow passage of large substrate
-gap junction/connexins (form intercellular pores in heart liver for particles MW=80

Front 4

rates of transport

Back 4

-carrier type limited by binding and dissociation rates
-channel and transporters limited by concentrations and saturate at maximum rate

Front 5

uniporters

Back 5

-specific solute
-transporter conformational change
-unbind solute on other mem side
-empty side re-arranges
all rxn are reversible driven by solute gradient

Front 6

glu transporters and glu-glu exchange

Back 6

rxns that open to release glu on other side occur rarely
-the 3 rxns that bind glu occur rapidly
-if the concentration of glu is higher outside glu will be brought in faster

Front 7

symporters/ co-transporters

Back 7

-2 substances must bind and be released to the other side
-the energy of one substrate gradient must be enough to drive the other

Front 8

antiporters/exchangers

Back 8

-binding sites only reorient when bound
-energy from one ion gradient can be used to drive an ion in another reaction
-ions are exchanged stoichiometrically
-channels must be coupled and ions are stored inside in order to produce ion gradients

Front 9

ion pumps

Back 9

-transport of ions liked to another source of energy, often w/ hydrolysis

Front 10

p-type pumps

Back 10

-p of atp is covalently bound to the cytoplasmic side of the protein when atp is hydrolyzed
which provides the energy for the Na pump