Name: Hour: Biology Unit 3-Cells Diffusion & Osmosis Lab Activities Cells use various processes of diffusion and osmosis in order to transport particles throughout a cell and across the cell membrane. Today we will observe the processes of diffusion and osmosis to understand what happens during them, how they work, and to better understand how cells transport particles using these processes. Part 1: Food Coloring & Water 1) Directions: (Food Coloring & Room Temperature Water) a. Place a couple of drops of food coloring into room temperature water. b. Draw your picture to show how the food coloring has moved around. After 1 second After 5 seconds After 1 minute 2) Directions: (Food Coloring & Boiling Water) a. Place a couple of drops of food coloring into the boiling water. b. Draw your picture to show how the food coloring has moved around. After 1 second After 5 seconds After 1 minute
3) Directions: (Food Coloring & Ice Water) a. Place a couple of drops of food coloring into the boiling water. b. Draw your picture to show how the food coloring has moved around. After 1 second After 5 seconds After 1 minute 4) Food Coloring & Water Questions: #1- How did the food coloring move through the cold, room temperature, and warm water differently? #2- Why do you think the food coloring moved through the cold, room temperature, and warm water at different rates? #3- What is food coloring made of on the most basic level? (Hint: It s made of matter! )
Part 2: Food Coloring, Water, and Oil 1) Directions: a. Fill the beaker ½ full of water. b. Place a small amount of oil on top of the water. After the oil separates out, there should be about 3-4mL thick of oil on top of the water. c. Add some food coloring on top of the oil layer. d. Draw a picture of the set up below: 2) Questions: #1- Where was there a higher concentration of food coloring? On top of the oil, or underneath (in the water)? #2- Eventually, what happened with the food coloring? #3- The particles always move in that same direction as they did in this activity. What direction is that? (HINT: Think about the concentration! )
What do you think DIFFUSION IS? All of the demos/activities we just saw showed DIFFUSION. Use what you saw, over and over again, to come up with a definition of DIFFUSION.
Part 3: Egg Osmosis 1) Friday Directions: a. Grab 2 plastic cups. b. Write on each cup one of the following: Water, Sugar c. Now make sure to write your group names on your cups and your hour. d. Grab 2 hardboiled eggs and remove them from their shells. e. Weigh each one, AND MAKE SURE to keep track of which goes in which cup: (The eggs should be weighed OUTSIDE the cups or BY THEMSELVES!) The Egg Going Into Water = g The Egg Going Into Sugar Solution = g f. Place the correct eggs in each cup. Let sit overnight. 2) Monday Directions: a. Find your cups. b. Pour the water down the sink and gently place its egg back into your cup. c. Throw out the sugar solution and cup, rinse off its egg gently, and place in a new cup. d. Weigh each one, AND MAKE SURE to keep track of which egg each is: (The eggs should be weighed OUTSIDE the cups or BY THEMSELVES!) The Water Egg = g The Sugar Solution Egg = g 3) Egg Osmosis Questions: #1- What happened to the weight of the Water Egg? #2- What happened to the size of the Water Egg? #3- When we started the lab, was there more water inside or outside of the egg?
#4- Why do you think the weight and size of the Water Egg changed? Draw a picture to show and visually explain what happened. #5- What happened to the weight of the Sugar Solution Egg? #6- What happened to the size of the Sugar Solution Egg? #7- When we started the lab, was there more water inside or outside the Sugar Solution egg? #8- Why do you think the weight and size of the Sugar Solution Egg changed? Draw a picture to show and visually explain what happened.
Part 4: Starch and Iodine 1) Look in your Starch and Glucose Beaker: a. The liquid in the beaker is water + iodine solution. b. The liquid in the baggy is water + starch. c. I set them up overnight and let them sit. 2) What Do You See? Draw and label a picture below for the INITIAL SET UP Draw and label a picture below for the FINAL RESULTS 3) Starch & Iodine Questions: #1- What do you see inside the starch and water baggy? #2- Why did the inside of the starch and water baggy change? #3- Did anything change in the iodine filled beaker?
#4- This demo shows the diffusion of a substance, either the iodine-solution or the starchsolution. A) Which solution do you think diffused? B) What evidence do you have that this specific substance diffused? What do you think OSMOSIS IS? All of the demos/activities we just saw showed OSMOSIS. Use what you saw, over and over again, to come up with a definition of OSMOSIS.
--THE CONCLUSION-- Define Diffusion: Draw A Picture of Diffusion: What Evidence Did We Collect To Show This?
Define Osmosis: Draw A Picture of Osmosis: What Evidence Did We Collect To Show This?