This group activity uses building blocks such as Legos, to simulate the process of eating macromolecules, digesting them and using them in the body in the cell membrane for structural purposes. It helps the student to get the connection between catabolism and anabolism (metabolism), the purpose of eating food, and the use of monomers in cellular structures. My students loved using their imaginations to figure out what their monomers would be and how to put them together to rebuild cell structures. I needed a box of 650 Legos, which I divided into 9 groups in baggies. You could use other types of blocks, but if they are too big, they won't fit in the cell membrane picture.