Review and Virtual Labs - Diffusion and Osmosis - Kathy Egbert | Library

Review

PART A: Diffusion Review .  Go to the following link. Complete the questions #1-7 while you go through the simulation on diffusion

 https://www.wisc-online.com/learn/natural-science/life-science/ap1903/the-cell-passive-transport-diffusion 

https://www.wisc-online.com/learn/natural-science/life-science/ap1903/the-cell-passive-transport-diffusion

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Diffusion is

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At the very beginning, how does the concentration of the blue particles on Side A compare to that of Side B?

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Kinetic energy allows molecules to

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Net diffusion moves down the concentration gradient from areas of

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Eventually the two sides will come to equilibrium which is when the concentration of particles are equal on both sides.

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What happens to the movement of molecules when the temperature is raised?

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What happens to the movement of molecules when their temperature is lowered?

After viewing the following video about diffusion, answer the 5 multiple choice questions.

http://highered.mheducation.com/sites/0072495855/student_view0/chapter2/animation__how_diffusion_works.html

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Video Diffusion Q1: Simple diffusion is defined as the movement of

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Video Diffusion Q2: When sugar is mixed with water, equilibrium is reached when

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Video Diffusion Q3: The rate of diffusion is affected by which of the following?

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Video Diffusion Q4: The molecules in a solid lump of sugar do not move.

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Video Diffusion Q5: Diffusion is one of the processes whereby materials are exchanged between a cell and its environment.

PART C: Osmosis Review.  Go to the following link. Complete the questions below while you go through the simulation on osmosis.

https://www.wisc-online.com/learn/natural-science/life-science/ap11003/the-cell-passive-transport-osmosis

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Osmosis is

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Compared to simple diffusion which is the movement of particles, osmosis is only the movement of water through a semipermeable membrane.

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The dashed line in the beaker separating the two sides represents the semipermeable membrane.

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Why is the assumption made that the large molecules will stay on their own side of the membrane?

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Because molecules will move from one side to another to come into equilibrium, the concentration of water moves from side B to side A. Therefore, the water level on side A goes

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In living organisms, cells must be in an ____________ solution where water leaves and enters the cell at the same rate.

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If a cell is placed in an hypertonic environment (you need to click on the "View Movie" in the simulation to observe), then an animal cell will

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If a cell is placed in an hypotonic environment (you need to click on the "View Movie" in the simulation to observe), then an animal cell will

PART D: 
Go to: http://highered.mheducation.com/sites/0072495855/student_view0/chapter2/animation__how_osmosis_works.html 

After the Osmosis video answer the 5 questions below: 

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Video Osmosis Q1: Osmosis is best defined as the movement of

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Video Osmosis Q2: Which of the following will pass through a cell membrane most easily?

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Video Osmosis Q3: A red blood cell placed in a hypertonic medium will

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Video Osmosis Q4: A 5% urea solution is hypotonic to a 10% urea solution.

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Video Osmosis Q5: If a cell is placed in an isotonic medium, there will be no net movement of water.

PART E: Hypotonic vs Isotonic vs Hypertonic Solutions

Go to the following hyperlink:

http://www.glencoe.com/sites/common_assets/science/virtual_labs/LS03/LS03.html

Read the general information on the side panel which also has instructins for how to do the lab. Move each of the specimens into the three solutions and record your observations in the next question boxes.

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Human blood cell - appearance in hypotonic solution

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Human blood cell - net movement of water in hypotonic solution

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Human blood cell - appearance in isotonic solution

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Human blood cell - net movement of water in isotonic solution

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Human blood cell - appearance in hypertonic solution

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Human blood cell - net movement of water in hypertonic solution

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Elodea (plant cell) - appearance in hypotonic solution

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Elodea (plant cell) - net movement of water in hypotonic solution

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Elodea (plant cell) - appearance in isotonic solution

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Elodea (plant cell) - net movement of water in isotonic solution

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Elodea (plant cell) - appearance in hypertonic solution

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Elodea (plant cell) - new movement of water in hypertonic solution

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Paramecium (single celled prokaryote) - appearance in hypotonic solution

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Paramecium (single celled prokaryote) - net movement of water in hypotonic solution

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Paramecium (single celled prokaryote) - appearance in isotonic solution

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Paramecium (single celled prokaryote) - new movement of water in an isotonic solution

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Paramecium (single celled prokaryote) - appearance in hypertonic solution

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Paramecium (single celled prokaryote) - new movement of water in a hypertonic solution

Summary comparing and contrasting plant cell vs animal cell in the three solutions:

	Hypotonic Solution	Hypertonic Solution
Plant Cell - Elodea	the central vacule swells, but the cell wall prevents the cell from bursting	inside of cell shrinks and pulls away from the cell wall; cell walls stay in place
Animal Cell - Human blood	swells and eventually lyses (breaks apart)	cell shrinks and gets smaller and smaller until it dies

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Paramecium belong to the Kingdom Protista. Since you observed how the paramecium responded in the different solutions, predict whether paramecium are more closely related to the Animal Kingdom or the Plant Kingdom.

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Review Question: All three of these cells share the following characteristics: have a cell membrane, have cytoplasm, have genetic material, and have ribosomes.

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If you were sick and in the hospital, especially with something like the flu where you might become dehydrated, you may receive an IV of saline solution to return your body to homeostasis. What is the concentration of the IV saline (salt) solution?

The concentration of salt is 0.9% in human red blood cells.

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Often movies or stories tell about a person ship-wrecked on an island or stranded on a life raft in the ocean without any access to fresh water. Explain why drinking the ocean water isn't a good idea.

The concentration of salt averages between 3 to 4% in ocean sea water.

PART F: Movement of particles in solids and liquids

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Based on what you learned from this video "The Effect of Molecular Weight on Rate of Diffusion" comparing a hydrogen molecule and a oxygen molecule, predict whether methylene blue, blue dye, C16H18ClN3S , molecules diffusses faster than potassium permanganate, purple dye, KMnO4.

Look at the molecular formula of each substance

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After viewing "Diffusion Through a Semi-permeable Membrane", answer the next questions.

Where is the iodine at the start of the experiment?

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Where are the starch molecules?

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Why are the starch molecules confined to the bag?

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What is the final color of the solution inside the bag and why?

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What would happen if the starch molecules could pass out of the bag?

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Based on the information from these experiments, speculate on whether a sulfate ion would move across the dialysis membrane.

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Based on the information from these experiments, speculate on whether a large protein molecule would be able to move across the dialysis membrane.

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Review: Some of the substances were permeable (able to pass through) to the dialysis tubing. Which ones?

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Review: In each case, the molecules moved from a lower to a higher concentration.

read the question carefully, don't let me trick you

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Review and Virtual Labs - Diffusion and Osmosis