5.3 Ohm's Law Flashcards
1
Q
Electrochemical gradient determines
A
direction of ion movement (in or out of cell)
2
Q
Rate at which ions move across membrane factors (4 answers)
A
1) size of electrochemical gradient
2) nature of the ion
3) number of open ion channels
4) properties of ion channel
3
Q
Current
A
flow of ions
4
Q
Big current
A
many ions flowing per second
5
Q
Small current
A
few ions flowing per second
6
Q
Voltage
A
potential difference
7
Q
No ion flow without..
A
potential difference
8
Q
Resistance
A
width of path
9
Q
Low resistance
A
wide path
10
Q
High resistance
A
narrow path
11
Q
Relationship between current and resistance
A
low resistance=big current
high resistance=small current
(same voltage)
12
Q
Ohm’s law
A
Current (I)= Volts (V)/ Resistance (R)
13
Q
Rearranged Ohm’s law
A
Current (I)= Volts (V) x Conductance
(where conductance is 1/R)
