How did life on Earth begin? Many scientists believe that the first cells were simply aggregates of organic molecules called coacervates. In this lab, students will first test and observe the effect of pH on coacervate formation. In the second part of the activity, students must design their own experiment to test the effect of a different variable on coacervate formation.
This biology lab is appropriate for students in grades 9 - 12, and includes the following:
1. Guided lab activity on making coacervates.
2. 11 slide PowerPoint on the characteristics of life.
3. A student designed lab activity testing a new variable in the making of coacervates.
This lab makes an excellent addition to your unit on the origin of life and the early history of life on Earth. I use this lab after teaching this material: The History of Life on Earth PowerPoint With Notes
1. To simulate Oparin’s work by mixing a protein solution with a carbohydrate solution to produce coacervates.
2. To observe the shared characteristics between coacervates and living cells.
3. To determine the ideal pH level for producing the most coacervates in a solution.
Materials and supplies required for this lab include: Glass test tube with cap, Graduated cylinders, Gelatin solution (protein), Gum Arabic (carbohydrate), Glass stirring rod, pH paper, .1M HCl solution, Dropping pipets, Microscope, Test tube rack, Microscope slides.
Included in the download are two versions of the guided lab activity. Use Version 1 (3 pages) of the lab if you want your students to use their own notebook paper to write their own lab reports. Use Version 2 (6 pages) of the lab if you want to print the student data handouts and allow the students to record their data and answers on these handouts.
The “student designed experiment” (5 pages) is optional, but highly recommended. This is a time consuming activity, but it is well worth the time to teach your students how to design and carry out a lab experiment. In the handouts provided for the student designed experiment, 6 options are given for additional variables that can be tested. I assign one of these variables to each group of students. You may think of additional testable options that you would like to include. At the conclusion of the lab, I have each group make a short report to the class, giving their hypothesis and the results they obtained.
Also included is a 7 page "Teacher Guide to the Lab." This includes information on how to prep the lab, directions for mixing solutions, tips on setting up the lab, sample data, sample graph, and answers to all questions.
All documents and the PowerPoint are included in multiple formats (doc, docx, PDF, ppt and pptx).
Approximate time required to complete:
Teacher preparation: 30 minutes
Student lab activity: 45 minutes. Students may have to complete some questions for homework.
Student designed experiment: 30 minutes for planning and 45 minutes for conducting lab and completing handouts.
Related products include:
The History of Life on Earth PowerPoint With Notes for Teacher and Student
Darwin's Theory of Evolution PowerPoint and Notes
History of Life on Earth Question and Answer Review PowerPoint
History of Life on Earth Quizzes
Evolution and Classification: Warm Ups, Bell Ringers and Interactive Notebooks
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