Diffusion

Question 1

Define diffusion

Answer 1

The net movement of molecules from a region of high conc to a region of lower conc down the concentration gradient.
It is a passive process as the particles have natural kinetic energy

Question 2

What is it called when the conc outside cell= conc inside cell

Answer 2

Equilibrium

Question 3

Factors affecting rate of diffusion

Answer 3

1) steepness of the concentration gradient. The bigger the difference the quicker the rate
2) distance. The shorter the route the quicker the rate ( alveoli one cell thick)
3) surface area. Greater the SA the quicker the rate, more molecules can cross at once

Question 4

What is Ficks law

Answer 4

Rate of diffusion is proportional to (SA x difference in concentration)/length of diffusion path

Question 5

What is the difference between simple and facilitated diffusion

Answer 5

Facilitated needs protein channels to transport the molecules

Question 6

What do channel proteins do

Answer 6

Form an aqueous pore across membrane no energy required

Question 7

What do carrier proteins do

Answer 7

Bind to the solute change shape and release the solute on the other side. They allow active transport (energy required)