Lesson 2
Purpose of the work:
- to prove the presence or absence of fats in bread and nuts
Teacher’s guide:
- Divide the students so that there are 3 students in each group.
- Before proceeding with the laboratory work, read the safety rules by clicking on the link:
- To download the worksheet, please follow the link:
Theoretical part
Fats are organic compounds that, along with proteins and carbohydrates, are necessarily present in cells. They belong to a large group of organic fat-like compounds, a class of lipids.
Practical part
First, prepare the necessary items:
- a slice of bread
- nuts
- vegetable oil
Step 1. Using a mortar and pestle, grind the required amount of bread and nuts.
Step 2. Add a little water and mix the resulting mixture until a homogeneous mass is obtained.
Step 3. With a Q-tip, take a sample of three objects and draw a zig-zag shape on the filter paper. In this work, vegetable oil is used as an indicator sample.
Step 4. As soon as the water dries from the surface of the paper, observe and in your copybook write down the answers to the following questions:
- What changes were observed in each sample after drying?
- Drawing conclusions, which product can be claimed for the presence of fat?
- Based on which property of fats did you come to this conclusion?
Conclusion
In this practical work, students studied the properties of fats and how to determine these substances in the composition of products. The acquired knowledge and skills can be applied in the future during lessons and in everyday life.