Selectively Permeable Selectively Permeable Membranes “Lab”Membranes “Lab”

Selectively Permeable Selectively Permeable Membranes “Lab”Membranes “Lab”

Honors BiologyHonors Biology

Pre-lab• Before you begin the lab, it is

important that you answer the 5 pre-lab questions.

• Use the next few slides (or your notes or the book) if you do not already know the answers to these questions!

Did you know?• Isotonic solutions have the same

amount of solute as a cell

Did you know?• Hypertonic Solutions have more

solute than a cell

Did you know?• Hypotonic solutions have less

solute than a cell

Still confused?Here is a great animation of hypertonic/hypertonic

cells:http://www.zerobio.com/flashmx/tonicity.swf

Here are pictures of actual cells in all 3 solutions:http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter21/animation__hemolysis_and_crenation.html

Part IPart IPart IPart I

Plant Root Tissues in SolutionPlant Root Tissues in Solution

Plant Tissue in Solution

15% Salt Solution

5% Salt Solution

Distilled Water

Part IIPart IIPart IIPart II

Plant Leaf Cells in SolutionPlant Leaf Cells in Solution

Plant Leaf Cells in SolutionInitial Image

Salt Water Solution

Distilled Water

Want to see another image for Part II?

• Here is a link to a YouTube video that will help you see what happens to a cell placed in a salt water solution: http://www.youtube.com/watch?v=lzDlGl3b4is&feature=related

• This is an onion cell, so you will not see chloroplasts, but it will really help you see the change in size of the cell! Remember that the cell wall will not change size, just the cell membrane.

Part IIIPart IIIPart IIIPart III

Simulated Animal Cells in Simulated Animal Cells in SolutionSolution

Simulated Animal Cells in Solution

Benedict’s Test After 24 Hours

Iodine Test After 24 Hours

Initial Set-Up

Post-Lab• Now answer the 5 post-lab questions. • If you have any questions please see

your teacher! You will be designing your own lab investigations in the coming week and all of the information from this lab will be important to understand!