Diffusion and Osmosis

TSWBAT identify the process of osmosis and diffusion via the gummi bear lab -analyze diffusion through a sand baggie and apply the concepts of hypotonic, hypertonic, and isotonic to the activity

• On a blank sheet of paper

– Write the equation for cellular respiration.

– Where does cellular respiration occur in the cell?

– List the organelles that help to make proteins – What is the difference between the rough and the smooth endoplasmic reticulum?

• • •

Solvent – what dissolve something Solute – what is being dissolved

Diffusion

– Random motion drives diffusion – http://highered.mcgraw hill.com/sites/0072495855/studen t_view0/chapter2/animation__ho w_diffusion_works.html

2 3 1 (water) 4

Osmosis

• Diffusion of water large molecules through a semi permeable membrane – Semi-permeable: permeable to solvents (WATER), but not to – High [water] to low [water] • Dissolved molecules (i.e. glucose, starch) are called solutes • REMEMBER: Water = solvent Glucose, Starch = solutes http://highered.mcgrawhill.com/sites/0072495855/student_view0/cha pter2/animation__how_osmosis_works.html

Effect of Water on Cells

• Hypertonic Environment – High [solute], low [water] – The cell will shrink – Plasmolysis – cell death

Hypotonic Environment

– High [water], low [solute] – Plants – turgor pressure – plant like this!!

– Animals – cytolysis – cell bursting • Isotonic Environment – [water] = [solute]

Hypertonic Isotonic Hypotonic

Part 3 pg. 85

Osmosis in Living Cells

Cellulose in cell wall

Osmosis in Red Blood Cells

•  0.9% saline  10% NaCl  Distilled water Isotonic Plasmolysis Predictions?

Hypertonic Hypotonic

Osmosis in Plant Cells

Plasmolysis •.

 10% NaCl  Distilled water Hypertonic Predictions?

Hypotonic

Animations

Dialysis Bag Experiment • http://ccollege.hccs.cc.tx.us/instru/Biology/AllStudy Pages/Diffusion_Osmosis/Baggif.swf

Elodea Cell • http://ccollege.hccs.cc.tx.us/instru/Biology/AllStudy Pages/Diffusion_Osmosis/Elodeagif.swf

Osmosis • http://ull.chemistry.uakron.edu/genobc/animations/o smosis.mov

Transportation of Molecules

• Passive Transport -Movement of molecules across a semi-permeable membrane - no energy required • Active Transport -Movement of molecules across a semi-permeable membrane against a concentration gradient with a protein - ENERGY – ATP • Facilitated Diffusion -Movement of molecules across a semi-permeable membrane with a protein - no energy required

Effect of Water on RBC