Diffusion

Question 1

What occurs during passive diffusion?

Answer 1

• all partials are constantly moving due to the kinetic energy they possess
• the motion is random with no set pattern to the way the particles move around
• the particles are constantly bouncing off one another as well as off other objects so are distributed evenly

Question 2

what is the definition of diffusion?

Answer 2

-the net movement of molecules or ions from a region of high concentration to lie concentration until equilibrium is reached

Question 3

what are protein channels?

Answer 3

• proteins that form water filled hydrophilic channels across the membrane
• they allow specific water soluble ions to pass through
• the channels are selective and open in the presence of specific ions
• there’s no control of the entry or exit of ions
• the ions bind with the protein causing it to change shape in a way that closes it to one side of the membrane and opens it to the other

Question 4

what are carrier proteins?

Answer 4

• when a molecule specific to the protein is present it binds with the protein and causes it to change shape so the molecule is released to the inside of the membrane
• no external energy is needed
• the molecules move from one region when they are highly concentrated to one of lower concentration using only memetic energy of the molecules themselves

Question 5

What is facilitated diffusion?

Answer 5

• the use of transmembrane channels and carriers that span to make to movement of large and polar molecules across a partially permeable membrane easier
• it’s a passive process and relies on natural kinetic energy
• it occurs down a concentration gradient but differs when it reaches transmembrane carriers and channels