Chapter 7

Question 1

selectively permeable membrane

Answer 1

allows some substances to cross more easily than others
o Describes plasma membrane
o Aquaporin: enables billions of water molecules to pass through the cell each second
• Exist within lipid bilayer

Question 2

amphipathic

Answer 2

molecule which has both a hydrophilic and hydrophobic region

Question 3

fluid mosaic model

Answer 3

model where the membrane consists of a bunch of protein molecules bobbing up and down in a fluid layer of phospholipids
o Currently accepted model of arrangement of molecules in plasma membrane

Question 4

cholesterol

Answer 4

steroid that regulates membrane fluidity in the plasma membrane at different temperatures. (p. 127)

Question 5

transport proteins

Answer 5

where ions and polar molecules who cant membrane enter through

Question 6

channel proteins

Answer 6

transport proteins which function by having a hydrophilic channel that certain molecules/ions use as a tunnel
o INCREASE RATE of molecules passing through.

Question 7

aquaporins

Answer 7

channel proteins which allow up to 3 billion water molecules/second to enter. Single line- fitting ten at a time!

Question 8

carrier proteins

Answer 8

transport proteins which hold onto passengers and change shape to allow them to cross membrane
• Only allows certain substances to cross
Ex: “glucose transporter”