Unit 3 Membrane Transport

Question 1

simple diffusion

Answer 1

1. movement of small uncharged molecules through lipid bilayer
2. O2 or CO2
3. concentration gradient is difference in concentration of molecules across a membrane
4. linear

Question 2

facilitated diffusion

Answer 2

1. use of integral membrane protein as carrier
2. molecule still moves along its concentration gradient
3. Na+ and K+ gates or channels
4. hyperbolic

Question 3

osmosis

Answer 3

flow of water across a membrane from low solute to high solute concentration

Question 4

osmotic pressure

Answer 4

water moving from its area of high to low concentration

Question 5

tonicity

Answer 5

ability of solution to cause a cell to gain or lose water

Question 6

isotonic

Answer 6

solution with same non-penetrating solute concentration as cytosol

Question 7

hypertonic

Answer 7

solution with higher non-penetrating solute concentration than cytosol (lose water by osmosis and shrink)

Question 8

hypotonic

Answer 8

solution with lower non-penetrating solute concentration than cytosol
(gain water by osmosis and shrink)

Question 9

active transport

Answer 9

required to move molecules against a concentration gradient; requires transport molecules

Question 10

primary active transport

Answer 10

uses ATP to move molecule against gradient

1. Na+/K+ ATPase
2. Ca+ 2ATPase of sarcoplasmic reticulum

Question 11

secondary active transport

Answer 11

uses co-transport along with molecule moving along its concentration gradient

1. Na+/glucose transport
2. sodium gradient established by Na+/K+ ATPase

Question 12

uniport

Answer 12

unidirectional transport of ion or molecule; transporter specific for single ion or molecules

Question 13

antiport

Answer 13

1. movement of two molecules in opposite direction
2. requires conformation changes in transporter and it requires energy (ATP)
3. Ex. Na+/K+ ATPase

Question 14

symport

Answer 14

1. movement of two molecules in same direction

2. Na+/glucose transport

Question 15

solute transport

Answer 15

diffuse; active transport

Question 16

fluid movement

Answer 16

1. upstream end of capillary fluid exits
2. downstream end fluid returns
3. direction of movement due to hydrostatic pressure (BP) and osmotic pressure
4. hydrostatic pressure drops along length of capillary
5. osmotic pressure constant due to non-diffusable solutes in plasma

Question 17

hydrostatic pressure

Answer 17

water being pushed out by some force