Rolling and wheels in the natural world
No known multicellular organism (an organism made of many cells) can spin part of its body while keeping the rest of its body still. However, there are at least two examples of rotating parts used by cells. One example is a molecule called ATP synthase. ATP synthase is used to store and move energy. For example, it is used in the processes of photosynthesis (a way of storing energy from the sun) and oxidative phosphorylation (a way of releasing stored energy). ATP synthase is similar to flagellar motors, which are talked about below. Biologists (scientists who study life) think that ATP synthase is an example of modular evolution. In modular evolution, two parts with different jobs join together and pick up a new job.