transport across cell membranes

Question 1

passive transport 4

Answer 1

• in motion
• random movement
• constantly bouncing around
• net movement of molc or ions from a region of high conc to a reigon of low or equally distributed conc.

Question 2

facilitated diffusion 5

Answer 2

• charged ions and polor molc
• transmembrane channels
• passive
• down a conc grad
• uses protein channels and carrier proteins

Question 3

protein channels 5

Answer 3

• water filled (hydrophilic channels)
• specific water soluble ions
• ions not present=closed=controlled
• ions bind=change in shape
• closed on one side and open on the other

Question 4

carrier proteins 3

Answer 4

particles are taken up by carrier proteins = change in shape=release to other side

Question 5

osmosis 4

Answer 5

• passage of water from a high water potential to a low water potential through a selectively permeable membrane
• substance dissolved in solvent=solute
• solvent+solute=solution
• measured in kpa

Question 6

active transport 3

Answer 6

• movement from low to high using ATP and carrier proteins
• directly moves molc using ATP
• moves molc using a conc grad ->co transport

Question 7

how is active transport different to passive

Answer 7

• uses ATP
• against conc grad
• proteins (carrier) pumps
• selective

Question 8

Active transport of a single molc/ion

Answer 8

• molc bind to protein receptor site
• ATP binds to protein = ADP=change in protein =released
• protein releases phosphate =reverts shape in ADP->ATP during respiration