ABSTRACT: In our STEM activity with 13-14-year-old students, it was aimed to evaluate waste materials, create design products, learn about organelles, and develop three-dimensional thinking skills. Traditional lectures on cells and organelles are not enough to learn adequately. In our activity, which is prepared to understand both engineering design skills and molecular biology with a multi-disciplinary study of biology, students are presented with information and visuals about various organelles. Students were asked to prepare designs from domestic wastes by thinking in three dimensions of various cellular structures (endoplasmic reticulum, mitochondria, chloroplast, ribosome, nucleus, lysosome, Golgi apparatus, etc.). The students were excitedly prepared for this event, and they were happy to prepare completely their own material choices and original designs.