Serotonin (pictured below), widely known as the "happy chemical", has been implicated in depression, mood regulation, social behavior, appetite, sleep, memory, as well as many others. It binds to a protein known as the 5-HT receptor. This receptor has a glutamate involved in keeping the serotonin bound in. When the glutamate is mutated to an aspartate, or separately to an isoleucine, the binding curves below are observed H2 glutamate Glu lle 0 Asp HN NH2 Serotonin Serotonin] Based on the structure of glutamate and the structure of serotonin, what kind of interactions would you expect to be involved in holding serotonin in place. The binding curve of serotonin with aspartate did not shift much, indicating the receptor has the same affinity for serotonin whether it uses aspartate or glutamate In thinking about the structure of all three, propose a hypothesis for this. Based on the binding curve above, does the receptor have a higher or lower affinity for serotonin when isoleucine is in place of glutamate? Suggest a theory to support this. a. b. c.