The purpose of this article is to describe the possibilities of using worksheets in the teaching of lipids and proteins. The worksheet includes a concept map, suggestions for three safe experiments that can be performed with available household chemicals, and observation results. The worksheets were implemented into action research in two classes taught by the same teacher. The verification of the worksheets took 90 min. First, the students filled out the prediction cards, structured the concepts related to the topic of the worksheet, verified the worksheet, wrote the results of the verification, and finally, after performing the experiments, filled in the prediction cards again. It was found that students have a problem with the interpretation of the data and many of them lack the skills needed to carry out the experiment. The knowledge at the beginning and at the end of the lesson was verified by deciding on the truth of the statements on the prediction card. For lipids, students' input knowledge was 57% and output knowledge was 81%, while for proteins, students' input knowledge was 66% and output knowledge was 91%. The combination of work with a conceptual map and the implementation of experiments led to the consolidation of knowledge in these two thematic units of biochemistry.