lab 5 diffusion and osmosis quiz (unit 2) ib bio

what causes diffusion?

kinetic energy which causes molecules to bump into each other and move in new directions

random movement of molecules from an area of high concentration to an area of lower concentration

diffusion

in diffusion what will EVENTUALLY happen?

a dynamic equilibrium is established and concentration will be equal throughout the room with no net movement

diffusion of water through a selectively permeable membrane from a region of high water potential to a region of lower water potential

osmosis

what is water potential the measure of?

free energy of water in a solution

moves substances against a concentration gradient, from regions of low concentration to high concentration

active transport

what is dialysis?

the movement of a solute through a selectively permeable membrane 

In dialysis, what determines which substances can pass through the membrane?

the size of the minute pores in the tubing

how was the presence of the glucose tested?

Benedicts

how was the presence of starch tested?

with Lugols solution

when two solutions have the same concentration of solutes with no net change in the amount of water

isotonic

if two solutions differ in the concentration of solutes each has, the one with more solute is ______ to the one with less solute.

hypertonic

if two solutions differ in the concentration of solutes each has, the one with less solute is ______ to the one with more solute.

hypotonic

a solution that is hypertonic to the other must have _______ solute and therefore _____water

more; less

at standard atmospheric pressure, which solution has a higher water potential? 

hypotonic solutions have a higher water potential, so the net movement of water is from the hypotonic solution into the hypertonic solution

the ability to give up water

water potential

how is water potential affected?

the addition of solute → lowers the water potential 

pressure → increase in pressure increases the water potential

what does water potential measure?

the tendency of water to leave one place in favor of another, to diffuse down a water potential gradient

why does water move into a cell?

the presence of soltues in the cell lowers its water potential

when water moves into an animal cell, what happens?

it will burst

when water moves into an plant cell, what happens?

the cell wall creates a counteracting pressure and there will eventually e no net change between the plant cell and its surroundings

what lowers water potential?

an increase in solutes, and it is expressed as a negative number

what increases water potential?

pressure (think of water balloon).

what happens to animal cells in a solution with 0 molarity

swell and likely burst

what happens to animal cells in a solution with 1 molarity

shrivel

what happens to plant cells in a solution with 1 molarity

go through plasmolysis

what happens to plant cells in a solution with 0 molarity

becomes turgid

a measure of the concentration of dissolved particles (solutes) in a fluid (x intercept)

osmolality