Homeostasis

Stable internal condition

Three requirements of living thingsExchanging gases (CO2 out; O2

in)Taking in water, minerals, and

foodEliminating wastes

These tasks require molecules to move through the cell membrane.

Exchanging gases (CO2 out; O2 in)Taking in water, minerals,

and foodEliminating wastes

These tasks require molecules to move through the cell membrane.

Molecule movement through membranePassive transport

No energy used by the cell occurs naturally

Active transportRequires energy by the cell to

move molecules

Three functions of cell membraneSeparate contents of cell

from its surroundingsControls movement of

materials into and out of cellInteracts with the

environment surrounding the cell

Cell Membrane

http://www.wisc-online.com/objects/index_tj.asp?objID=AP1101

Diffusion

Movement of molecules from a region in which they are highly concentrated to a region in which they are less concentrated.

It will continue until the system reaches equilibrium, which means the molecules are randomly distributed throughout the system.

http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_diffusion_works.html

Equilibrium

Static- occurs when there is no action taking place

Dynamic-occurs when two opposing actions occur at the same rate but in opposite directions

Factors of diffusion

Amount of kinetic energy (temperature)

Size of the moleculeSmaller molecules will move

faster than larger onesCharges on the molecuesNature of material molecules

are moving through

Molecules permeable to cell membraneSmall molecues like:

CO2O2H2O

More oxygen would move into the cell then out if there is more oxygen outside the cell