Diffusion In Agar Cubes
Name:_______________________________________________Date:____ _____Block:______
Diffusion In Agar Cubes
Is Bigger Better? OR Is Smaller Smarter?
Adapted from Flinn Scientific Publication No. 10110
Introduction:
Diffusion is one of the very important processes by which substances such as nutrients, water, oxygen, and cellular wasted are transported between living cells and their environment. This activity will help you explore the relationship between diffusion and cell size by experimenting with model “cells.”
In this experiment, you will use agar cubes to which the indicator phenolphthalein has been added. Phenolphthalein is an acid/base indicator that turns pink in the presence of a base such as NaOH. Thus the surface of the agar cubes will turn pink immediately when put into a NaOH solution. The NaOH will continue to diffuse through the cube and gradually turn the inside of the cube pink. The guiding question for this lab is thus:
What determines the efficiency of diffusion throughout the model “cells”? Use this question to help formulate a hypothesis:
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Your hypothesis:
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Materials:
Agar
A ruler
0.1M NaOH per group 200mL
Knife
Large beaker
Spoon/Tongs
Procedure: 1. Each group will cut three agar cubes: A 3cm cube, a 2cm cube, and a 1cm cube. CUT AS ACCURATELY AS POSSIBLE. (This may be already completed for you.) 2. Pour 200mL of 0.1M sodium hydroxide solution into your 400mL beaker. 3. Immerse your 3 cubes in the sodium hydroxide solution, noting the time. 4. Let the cubes soak for approximately 10 minutes. 5. Periodically, gently stir the solution, or turn the cubes over. 6. After 10 minutes, use a spoon or tongs to
Diffusion In Agar Cubes
Is Bigger Better? OR Is Smaller Smarter?
Adapted from Flinn Scientific Publication No. 10110
Introduction:
Diffusion is one of the very important processes by which substances such as nutrients, water, oxygen, and cellular wasted are transported between living cells and their environment. This activity will help you explore the relationship between diffusion and cell size by experimenting with model “cells.”
In this experiment, you will use agar cubes to which the indicator phenolphthalein has been added. Phenolphthalein is an acid/base indicator that turns pink in the presence of a base such as NaOH. Thus the surface of the agar cubes will turn pink immediately when put into a NaOH solution. The NaOH will continue to diffuse through the cube and gradually turn the inside of the cube pink. The guiding question for this lab is thus:
What determines the efficiency of diffusion throughout the model “cells”? Use this question to help formulate a hypothesis:
-------------------------------------------------
Your hypothesis:
-------------------------------------------------
-------------------------------------------------
-------------------------------------------------
-------------------------------------------------
Materials:
Agar
A ruler
0.1M NaOH per group 200mL
Knife
Large beaker
Spoon/Tongs
Procedure: 1. Each group will cut three agar cubes: A 3cm cube, a 2cm cube, and a 1cm cube. CUT AS ACCURATELY AS POSSIBLE. (This may be already completed for you.) 2. Pour 200mL of 0.1M sodium hydroxide solution into your 400mL beaker. 3. Immerse your 3 cubes in the sodium hydroxide solution, noting the time. 4. Let the cubes soak for approximately 10 minutes. 5. Periodically, gently stir the solution, or turn the cubes over. 6. After 10 minutes, use a spoon or tongs to