BMS11004 WEEK 9 - TUESDAY

Question 1

define equilibrium potential

Answer 1

PD across membrane that exactly balances conc gradient for ion

Question 2

what is cation

Answer 2

positively charged, attracts to cathode

Question 3

what is anion

Answer 3

negatively charged, attracts to anode

Question 4

what is approximate equilibrium potential for Na+ if conc of Na+ is low in chamber 1, and high in chamber 2

Answer 4

+50mV

Question 5

how do neurons prevent not having chem or electrical gradient (which would kill cell)

Answer 5

permeability of membrane tightly controlled
membrane mainly permeable to K+ at rest
membrane permeability to Na+ is only increased upon cell stimulation
conc of K+ and Na+ are actively maintained by pumps