Chapter 4

Question 1

What is the function of the cell membrane

Answer 1

Structure, support, keep things in, keep things out

Question 2

What are the 3 main ways ions can move across the cell membrane

Answer 2

Simple diffusion, facilitated diffusion, active transport

Question 3

What is simple diffusion

Answer 3

Movement of ion down its gradient without the assistance of a protein

Question 4

What is facilitated diffusion

Answer 4

Movement of ion down its gradient with the assistance of a protein

Question 5

What is active transport

Answer 5

Movement of ion against its gradient

Requires energy

Question 6

What are 5 characteristics of the Na+/K+ ATPase pump

Answer 6

Moves 3 Na+ out
Moves 2 K+ in
Requires ATP
Ions are moving against the gradient
Makes membrane potential more negative

Question 7

What are the main factors that establish the membrane potential and how do they affect the membrane potential

Answer 7

Potassium more concentrated inside the cell - More negative
Sodium more concentrated inside the cell - Less negative
Na+-K+ ATPase pump - More negative
Proteins inside cell - More negative

Question 8

What is exocytosis?

Answer 8

Movement of vesicles from inside of cell to the cell membrane
Once they reach the membrane they release their contents