cell biology 2

Question 1

function of membrane

Answer 1

• define boundaries of a cell and organelles
• serve as a sites for biological functions
• possess transport proteins that regulate the movements of substances
• contain protein molecules that act as receptors to detect external signal
• provide mechanisms for cell-to-cell contact, adhesion, communication

Question 2

cholesterol

Answer 2

main sterol in animal cell membranes
increases membrane fluidity (acts as FLUIDITY BUFFER)

Question 3

lipids are mobile within their monolayer

Answer 3

rotation
lateral diffusion
(both movements are rapid and random)

Question 4

transition temperature Tm

Answer 4

the temperature at which lipid bilayer becomes fluid

Question 5

lipid rafts

Answer 5

localized regions of membrane lipids that are involved in cell signaling, detecting and responding to extracellular signals

Question 6

electrophoresis

Answer 6

• group of techniques that use an electric field to separate charged molecules
• how quickly a molecule moves during electrophoresis depends on both charge and size