Functions Of Channels And Transporters
Compiled By Simon Mwangi
Edition: 2024/25
, Science | Biochemistry I of VI pages
1. how do ion channels differ from aqueous pores? (2)
ion channels show ion selectivity
ion channels are not continuously open
2. how many different types of ion channels are there?
more than 100
3. in what types of cells are ion channels found? (3)
animal cellsplant cellsmicroorganisms
4. ion channel: K+ leak channeltypical location: function:
plasma membrane of most animal cells
maintenance of resting membrane potential
5. ion channel: voltage gated Na+ channeltypical location: function:
plasma membrane of nerve axon
generation of axon potentials
6. ion channel: voltage gated K+ channeltypical location: function:
plasma membrane of nerve cell axon
return of membrane to resting potential after initiation of action potential
7. ion channel: voltage gated Ca2+ channeltypical location: function:
plasma membrane of nerve terminal
stimulation of neurotransmitter release
8. ion channel: Ach receptor (ach-gated Na+ and Ca2+ channel)typical location: function:
plasma membrane of muscle cell (at neuromuscular junction)
excitatory synaptic signaling
9. ion channel: GABA receptor (GABA gated Cl- channel)typical location: function:
plasma membrane of many neurons (synapses)
inhibitory synaptic signaling
10. ion channel: stress-activated cation channeltypical location: function:
auditory hair cell in inner ear
detection of sound vibrations
11. a small flow of ions carries sufficient charge to cause a large change in the
membrane potential
12. the ions that give rise to the membrane potential lie in a thin, less than nm, surface layer close to the
1 nm
13. the ions that give rise to the membrane potential are held there by their on either side of the membrane
counterions
Biochemistry 2024/25 Edition