cell membrane & transport

Question 1

cell membranes

Answer 1

organize the chemical activities (metabolism) of cells

regulates what enters/exits the cell

plasma of membrane is selectively permeable

Question 2

phospholipids

Answer 2

main structural components of membranes

have a hydrophilic head and 2 hydrophobic tails

form 2 layer sheets called phospholipid bilayers with the heads facing outward and tails facing inward

Question 3

passive transport

Answer 3

diffusion across a membrane

substances diffuse through membranes without work by the cell

spreading from areas of high concentration to areas of low concentration

Question 4

facilitated diffusion

Answer 4

provides passage across membranes for molecules that do not diffuse freely

Question 5

osmosis

Answer 5

diffusion of water across a membrane

Question 6

active transport

Answer 6

movement of substances across a cell membrane from an area of low concentration to an area of high concentration, against the natural flow

requires energy