2.4.11~adaptations for rapid transport

Question 1

diffusion rate (simple and facilitated)

Answer 1

varies

Question 2

some cells are adapted for

Answer 2

rapid transport of molecules across their internal or external membranes

Question 3

factors affecting rate of diffusion

Answer 3

-temperature
-surface area of exchange surface
-concentration gradient across the exchange surface
-thickness of exchange surface

Question 4

3 factors effecting rate of simple diffusion

Answer 4

-surface area of exchange surface
-concentration gradient across exchange surface
-thickness of exchange surface

Question 5

how does surface area of exchange surface effect rate of simple diffusion

Answer 5

the larger the surface area of the exchange surface, the higher the rate of simple diffusion across that exchange surface

Question 6

how does concentration gradient across exchange surface effect rate of simple diffusion

Answer 6

the greater the difference in concentration on either side of the exchange surface, the higher the concentration gradient across the exchange surface, the higher the rate of simple diffusion

Question 7

how does diffusion effect concentration gradient

Answer 7

as diffusion occurs, the concentration gradient across the exchange surface decreases until and equilibrium is reached. this causes rate of diffusion to steadily decrease. is concentration gradient can be maintained the rate of simple diffusion remains high

Question 8

how does thickness of exchange surface effect rate of simple diffusion

Answer 8

the thinner the exchange surface, the higher the rate if simple diffusion (as shorter distance for molecules to travel)

Question 9

2 factors effecting rate of facilitated diffusion

Answer 9

-concentration gradient across exchange surface
-number of channel or carrier proteins available in the exchange surface

Question 10

how does concentration gradient effect rate of simple diffusion

Answer 10

the greater the difference in concentration on either side of the exchange surface the higher the rate of facilitated diffusion to a point

Question 11

how does number of channel proteins or carrier proteins available in exchange surface effect the rate of facilitated diffusion

Answer 11

once all carrier or channel proteins are in use, the rate of a facilitated diffusion in a particular molecule can no longer increase. this means that the greater the number of channel or carrier or proteins the higher the rate of facilitated diffusion