Membrane Transport

Question 1

What 3 components is the cell membrane made up of?

Answer 1

A phospholipid bilayer
Other lipids
Proteins

Question 2

Describe the structure of phospholipids and how they are arranged

Answer 2

The heads are phosphates and are hydrophilic (attract water)
The tails are fatty acids and are hydrophobic
Due to polarity, they arrange themselves so the heads are sticking out, attracted to the water.

Question 3

Define: diffusion

Answer 3

The net movement of molecules from a region of high concentration to a region of low concentration

Question 4

Describe simple diffusion and facilitated diffusion.

Answer 4

Simple diffusion: smaller molecules (O2, CO2) pass freely though the lipid bilayer
Facilitated diffusion: larger molecules pass through membrane proteins.

Question 5

Define: osmosis

Answer 5

The net movement of solvent (usually water) from a region of low concentration of solute to a region of high concentration of solute, through a partially permeable membrane.