So another example is the transport proteins found inside our cell membrane. So cell membranes consist of phospholipids. And so these transport proteins have to actually interact with these phospholipids to be able to actually transport those molecules and ions across the cell membrane. So we have many different types of examples, as we'll see in our study of biochemistry, in which proteins have to either interact with other proteins or with other macromolecules to actually carry out a specific type of function. Now, the final thing that we have to know about proteins is where they actually come from. So proteins are encoded by the DNA found inside our body.