LAB WRITE-UP FORMAT

Title: Modeling Osmotic Transport in Cells

Name/Class Color

  1. Purpose: To model osmotic transport in cells using a chicken egg (5 pts.)
  1. Prior Knowledge: What did/do I already know about the topic that relates to this lab? In this case you’ll be discussing cell transport and its importance to survival (What goes in…what goes out?). You’ll briefly explain the types of transport as well as the three tonic states (hyper, hypo, and iso) (15 pts.)
  1. Hypotheses (3): See data sheet.(10 pts.)
  1. Variables:(10 pts.)
  2. Manipulated/Independent
  3. Responding /Dependent
  4. Controlled
  1. Materials & Procedure (5 pts.)
    Materials:

1.1 Chicken Egg

2.White Vinegar (aka: acetic acid or ethanoic acid or…CH3COOH)

3.Analytical Balance

4.Ruler (metric)

5.String

6.H2O (water)

7.Corn Syrup

8.Food Coloring

9.Plastic Cup

Procedure:

1.With your partner, obtain one egg and one plastic cup.

2.Record your Day 1 hypothesis…you will be placing the egg in vinegar.

3.Use the analytical balance to mass your egg to the nearest 0.1 (1/10) gram.

4.Use the string and a metric ruler to measure the circumference of your egg in centimeters to the nearest 0.1 (1/10) cm.

5.Record any additional qualitative observations about your egg (color, texture, markings, etc.)

6.Use a Sharpie to write the names of your group members on your plastic cup.

7.Gently place your egg in the plastic cup and carefully add the 5 % acetic acid solution (vinegar) until your egg is covered.

8.Observe for at least five (5) minutes and record any additional observations.

9.Place your cup in the designated area labeled with your class color

10.After 24 hours (or the next opportunity after 24 hrs.) gently rinse the egg and re-measure mass and circumference.

11.Record your data.

12.Repeat 2- 11 with high fructose corn syrup and then with water/food coloring.

  1. Data Table: See Attached: (30 pts. For All Data and Graphs)
  2. Graphs: This will be a bar graph showing mass, circumference, Δ mass, and Δ circumference.(see data)
  3. Analysis Questions: (20 pts.)
    1. Analyze your data table and your graphs. Explain what you saw in the data that led you to draw your conclusions regarding the tonicity of the three solutions. Be specific as to what the numbers indicated.
    2. How could your understanding of osmotic transport be used in a practical sense (real-world)? Give a specific example.
  4. Possible Sources of Error: This is where you discuss anything that might have interfered with your experiment.(5 pts.)