Diffusion And Osmosis

Front 1

All molecules display _____, or _____; this is why a dissolved molecule tends to move around in a solution.

Back 1

random thermal motion; kinetic energy

Front 2

Kinetic energy causes molecules to diffuse outward from regions of __________ to regions of __________.

Back 2

high concentration, heat, and pressure to regions of low concentration, heat, and pressure

Front 3

The net movement of molecules from high to low concentration continues until ____________.

Back 3

the distribution of molecules becomes homogenous throughout the solution

Front 4

Brownian movement

Back 4

the irregular motion of small particles suspended in a liquid or a gas, caused by the bombardment of the particles by molecules of the medium

Front 5

diffusion

Back 5

the passive, directional movement of molecules through solutions and across membranes in a predictable direction

Front 6

The direction of diffusion depends on _______ of _____, _____, and _____

Back 6

the presence of a gradient of concentration, heat, and pressure

Front 7

differentially permeable

Back 7

the ability of a cell to selectively communicate with its environment through its cellular membrane; it allows some molecules to pass while retarding others

Front 8

basic structure of membranes

Back 8

a two-layered core of nonpolar lipid molecules that selects against molecules not readily soluble in lipids

Front 9

polar molecules

Back 9

have positively charged areas and negatively charged areas

Front 10

nonpolar molecules

Back 10

have no local areas of positive or negative charge

Front 11

2 characteristics of molecules that governs their passive movement through a lipid membrane

Back 11

polarity and size

Front 12

dialysis

Back 12

the separation of dissolved substances by means of their unequal diffusion through a differentially permeable membrane

Front 13

phenolphthalein

Back 13

a pH indicator that turns red in basic solutions

Front 14

iodine

Back 14

a starch indicator that changes from yellow to dark blue in the presence of starch

Front 15

osmosis

Back 15

the diffusion of water across a differentially permeable membrane

Front 16

solution

Back 16

a homogenous, liquid mixture of two or more kinds of molecules

Front 17

solvent

Back 17

a fluid that dissolves substances

Front 18

solute

Back 18

a substance dissolved in a solution

Front 19

hypotonic

Back 19

a solution with a lower concentration of solutes, especially those solutes that do not pass across the surrounding membrane; water moves across semipermeable membranes out of hypotonic solutions

Front 20

hypertonic

Back 20

a solution with a high concentration of solutes

Front 21

isotonic

Back 21

refers to two solutions that have equal concentrations of solutes

Front 22

water potential

Back 22

the combined effects of concentration and pressure such as that from cell walls; water will flow from an area of high to low

Front 23

erythrocytes

Back 23

living red blood cells

Front 24

osmosis into animal cells ____________

Back 24

increases the hydrostatic (water) pressure and bursts the cells because they lack cell walls

Front 25

hemolysis

Back 25

the destruction of a red blood cell by the influx of water in a hypotonic solution

Front 26

lysis

Back 26

the destruction of a cell by the influx of water in a hypotonic solution

Front 27

crenation

Back 27

A process resulting from osmosis in which red blood cells, in a hypertonic solution, undergo shrinkage and acquire a notched or scalloped surface.

Front 28

plasmolysis

Back 28

the shrinking of the cytoplasm of a plant cell in response to diffusion of water out of the cell and into a hypertonic solution surrounding a cell