Diffusion & Osmosis(Active and Passive transport and how

materials move in the cell)

Homeostasis

All living things have certain requirements they must satisfy in order to remain alive –

Keep a balance: Balance of temp, water, salt, nutritionTO DO THIS, THINGS MUST BE ABLE TO

MOVE IN A CELL

Selectively Permeable

Porous- like a screen on a windowLipid bilayer…

A membrane that allows only certain materials to cross it

Materials pass through pores in the membrane

Active transport

requires energy. (molecules move from an area of lesser to higher concentration)

BrainPop “Active Transport”

PASSIVE TRANSPORT

needs NO ENERGY! (molecules move from an area of higher to lesser concentration).

BrainPop “Passive Transport”

Diffusion

The movement of molecules from high concentrated to less concentrated.

BrainPop “Diffusion”

Diffusion

Osmosis

The diffusion of water across a selectively permeable membrane.

Osmosis is a type of Passive Transport.

Osmosis requires NO ENERGY.

TYPES OF SOLUTIONS

Hypertonic- a solution that causes a cell to shrink because of Osmosis.

Hypotonic- a solution that causes a cell to swell because of Osmosis.

Isotonic- a solution that causes no change in the size of the cell

OsmosisIn this picture a red

blood cell is put in a glass of distilled water. Because there is a higher concentration of water outside the cell, water enters the cell by OSMOSIS.  In this case too much water enters and the cell swells to the point of bursting open. 

HTTP://WWW.YOUTUBE.COM/WATCH?V=SSS3ETKAZYC

Hypotonic and hyper tonic solution video clip

Summary

Diffusion is: _______________

Osmosis is the: _______________

Active transport requires________. (molecules move from an area of _______ to ____________ concentration)

Passive transport needs __________! (molecules move from an area of ________ ___ _______________concentration).

Summary

Diffusion is the movement of molecules from an area of higher concentration to an area of lesser concentration.

Osmosis is the movement of water thru a semi permeable membrane.

Active transport requires energy. (molecules move from an area of lesser to higher concentration)

Passive transport needs NO ENERGY! (molecules move from an area of higher to lesser concentration).

Why are osmosis & diffusion important?

All living things have certain requirements they must satisfy in order to remain alive – maintain homeostasis

These include exchanging gases (usually CO2 and O2), taking in water, minerals, and food, and eliminating wastes.

These tasks happen at the cellular level.Molecules move through the cell membrane

by diffusionA balance, or EQUILIBRIUM, must be

maintained.