Flashcards in Membrane Potentials Deck (26):

1

## What is Valence?

### The charge on an ion given as z

2

## How do we calculate valence?

###
z = - [C(ion)] / [C(e-)]

C(ion) = Coulombs of ion

C(e-) = Coulombs of electron

3

## What is Faraday Constant?

### F = 96485 C/mol

4

## How do we calculate charge (q) of n moles with a valence z?

###
q = zFn

q = charge, z = valence, F = Faraday constant, n = moles

5

## What is Volatge?

### Electrical potential abbreviated V

6

## What is the formula for Current (i) with respect to time?

###
i = q/t

i = Current

q = charge

t =time

7

## What is the Nernst Equation?

###
μ(x) = nRT * ln( [x]1 / [x]2 )

μ(x) = Chemical potential energy of x

8

## How do we calculate the electrical potential energy (EPE)?

### μ(e) = zFn * V

9

## How do we calculate the Voltage using the Nernst equation and the formula for EPE?

###
V = - (RT/zF) * ln( [x]in/[x]out )

NOTE: this gives the answer in V not mV

10

## What is the general resting potential for cells?

### -70mV

11

## What is the formula for capacitance?

### q = CV in Faradays

12

## What is the capacitance of a normal cells?

### ~ 1.3 x 10^-11 F

13

## Electrogenic potential is created by ________________.

### Active Transport

14

## What is the Goldman equation?

### V = -RT/F * ln( {Pk[K]in + PNa[Na]in + PCl[Cl] out} / {Pk[K]out + PNa[Na]out + PCl[Cl]in} ) in V not mV

15

## What is Ve?

### Equilibrium Potential

16

## Flux is equal to?

###
j = i/zFA

i = current, j = flux, z = valence, F = Faraday's constant and A= area

17

## At Ve there is __________

### No flow

18

## Between 0 and Ve the ________________ will win

### The Chemical Gradient will win

19

## If we have

### The Electrical Gradient will win

20

## Current is given as the flow of __________charge into the cell. Therefore, the flow of ______ into the cell will be classed as an outward current.

###
Positive

Anions

21

## What is Ohm's law?

###
V = IR

V= voltage, I= Current and R= Resistance

22

## What is conductance?

### Conductance (G) is how easy it is to move charge, unit is Siemens (S)

23

## If only voltage moves an ion we can expect:

###
Ix = Gx * V

Ix = Current of x

Gx = Conductance of x

24

## What is Unitary Conductance (g)?

### The number of channels in the membrane and the proportion that are open

25

## How does voltage change cell conductance?

### By opening ion channels

26