5.4 Influences on movements of ions

Question 1

Effect of size of electrochemical gradient

Answer 1

High electrochemical gradient:

1) strongly negative

2) high concentration gradient

Low electrochemical gradient:

1) weakly negative

2) low concentration gradient

Question 2

Effect of nature of ion

Answer 2

Sodium ions:

high electrochemical gradient

Chloride ions:

low electrochemical gradient

(concentration gradient high but electrical gradient in the wrong direction)

Question 3

Effect of number of open ion channels

Answer 3

more open channels=faster rate of movement across membrane

(directly proportional to number of ion channels open)

Question 4

Effect of properties of ion channels (2 answers)

Answer 4

1) selectivity

2) permeability

Question 5

Selectivity (2 answers)

Answer 5

sodium selectivity channel have filters to only allows specific ions to pass through

there is favorable electrochemical gradient for potassium to move from outside to inside but sodium selective channel won’t allow it through

Question 6

Permeability

Answer 6

high permeability=increase rate of sodium movement= low resistance