5.2

Question 1

Relate the concentration gradient of molecules to simple diffusion

Answer 1

Diffusion is the movement of molecules from high concentration to low concentration

Question 2

Contrast between movement of nonpolar vs polar molecules across a membrane

Answer 2

o SMALL NONpolar (hydrophobic) molecules move FREELY across the membrane
o POLAR (hydrophilic) molecules CAN’T move freely across the membrane

Question 3

Differentiate between simple diffusion and facilitated diffusion.

Answer 3

o Simple diffusion- the movement of molecules follows the concentration gradient (high->low) and pass through the membrane
o Facilitated diffusion- movement of molecules can go in either direction and pass through membrane using PROTEIN CHANNELS

Question 4

Differentiate between channel proteins and carrier proteins.

Answer 4

o Channel proteins: create hydroPHILIC channels that allow molecules to pass through (each is specific for a specific molecule)
o Carrier proteins: bind specifically to molecules they assist (limited by # of transporters). undergo conformational change to transport

Question 5

Predict the direction of water movement by osmosis.

Answer 5

Water will move where solvent concentration is higher to balance. (low to high/against concentration gradient)

Question 6

Differentiate between hypertonic, hypotonic, and isotonic solutions

Answer 6

o Isotonic= solute concentration is the same in the cell and outside the cell
o Hypertonic= higher solute concentration OUTSIDE the cell vs inside the cell (cell SHRINKS)
o Hypotonic= higher solute concentration IN the cell vs outside the cell (cell SWELLS)

Question 7

Explain osmotic pressure

Answer 7

The force needed to stop water from diffusion through a membrane by osmosis. When levels are equal so water doesn’t need to move across the membrane