Biology 1 - UNIT 2_ Lab #3 - Lab Write-Up-2

Biology 1 - UNIT 2: Lab #3 and #4 Worksheet - Lab Write-Up Complete a write-up for both labs. All parts of the Lab Write up need to be completed to earn a grade for the lab. Be sure to use complete sentences. Lab Title Lab #3: Egg Osmosis Problem : What is the problem you are trying to answer? In which liquid will water move into the egg? In which liquid will water move out from the egg? Hypothesis Write this in an if… then format. When osmosis and diffusion occur, the concentrations of the two compounds are different, which is evidence that equilibrium can be achieved. Method : Summarize your method. 1. Measure out three eggs and label them around the glass 2. Cover them with an equal amount of white vinegar for 24 hours. If it still doesn’t melt, close the shell for a bit. 3. Repeat the measurement and inspection after washing. Prepare with care! 4. Then prepare your solutions: 1. Glass1: Type “hypertonic” by name. Pour one cup of corn syrup into a bowl. 2. Glass 2: Label “isotonic”. Fill one measuring cup with ½ teaspoon corn syrup and fill the rest with water. Stir until smooth. Pour the corn syrup into a glass (remember to drain all the syrup). 3. Glass 3: Hypotonic label”. Add 1 cup of water. 4. The eggs should be placed gently in a glass vial and allowed to remain for another 24 hours 5. The circumference of the eggs should be measured and recorded after 24 hours. Results : What data did you collect? Include a data table. What do the results tell you about your experiment? Egg Initial Circumfere nce Circumferen ce after Vinegar Initial Volume of Liquid Final Circumferen ce Final Volume of Liquid Visual Observati ons #1 – hyperto nic 114gm 62gm 200 ml 176 ml Mass decre ases #2 – isotonic 96gm 95gm 200 ml 1ml Mass does not chang e #3 - hypotoni c 62gm 102gm 200 ml 40m l Mass increa ses Photographic Evidence :