Chapter 4 - Cell Membrane Transport

Question 1

simple diffusion

Answer 1

the movement of a molecule into or out of the cell by its own thermal motion

Question 2

proteins that actively transport molecules across a membrane

Answer 2

pumps

Question 3

pushes particles from area of higher concentration to area of lower concentration

Answer 3

chemical driving force

Question 4

difference in the concentration of a substance between regions

Answer 4

concentration gradient

Question 5

difference in energy due to a separation of charge that acts to move ions from high energy to low energy

Answer 5

electrical driving force

Question 6

electrochemical driving force

Answer 6

the sum of the chemical and electrical driving forces

Question 7

difference in electrical potential or voltage that exists across the membranes of most cells

Answer 7

membrane potential

Question 8

cations

Answer 8

ions with a positive chaarge

Question 9

anions

Answer 9

ions with a negative charge

Question 10

Although some water crosses the lipid layer by simple diffusion, most water diffuses across cell membranes through _____, highly selective pores that permit water.

Answer 10

aquaporins

Question 11

carrier

Answer 11

transmembrane protein that binds molecules on one side of a membrane and transports them to the other side

Question 12

“cell-drinking”

Answer 12

pinocytosis

Question 13

“cell-eating”

Answer 13

phagocytosis

Question 14

What are the three forms of endocytosis?

Answer 14

1. phagocytosis
2. pinocytosis
3. receptor-mediated endocytosis