The Nature of Plant and Animal Fats

Exploration

Objectives

Students will visually inspect and record observations of various fats from plant and animal sources.

Students will list the various physical properties of plant and animal fats at room temperature and compare/contrast plant and animal sources.

Students will perform a brown paper test to verify the presence of fats in each sample.

Students will inspect omega-3 oil from supplements and make a hypothesis about where “fish oil” best fits into fat classification (plant or animal).

Lesson Materials

Fats from plants in small clear containers (e.g. beakers, test tubes, etc.) labeled 1-4 each with the same amount:

• Corn oil
• Olive oil
• Sesame oil
• Canola Oil

Fats from animals in small clear containers labeled 5-9 each with the same amount:

• Butter
• Cream cheese
• Lard (if you can find it)
• Bacon fat (from cooking)
• Chicken fat (from cooking)

Fish oil supplement capsules (a combination of fish-based and algae-based capsules) enough for one per student.

Brown paper
Toothpicks

Fats Analysis Lab

Procedures

1. Student groups will be given samples of plant and animal fats and asked to make observations about their physical properties and record data in a table.  Students will use a brown paper test to verify the presence of fats. Students should include sensory observations of the physical properties in the data table.  This can be performed with labels for the fats or no labels in which students need to make their best hypothesis about which fats are which. Students may smell samples of fats, and in this case, feel samples but should not be tasted so they understand proper lab protocol.

2.  After all student groups have had a chance to make sensory observations they will share ideas with the class on properties of animal and plant fats at room temperature.  Data can be collected as a class on a board for all students to observe and check for agreement.

3.  Individual students in each group will be given a fish oil supplement capsule (either fish based or algae based) so they can make sensory observations about it's physical properties and develop a hypothesis whether they think it is best classified as plant or animal fat. Students will use a toothpick to puncture the capsule and brown paper test to verify the presence of fats.

4. Each student will share their thoughts with their group members and come to a consensus about fish oil fat classification. Student groups will share ideas with the class on how to best classify the fish oil supplement by providing evidence when compared to the other fats.

Formative Assessment  Can you identify connections between fish like menhaden, the marine food chain, and the origin of "fish oil"?  Where does "fish oil" come from?

References

For more information download the Content Primer