What causes the response in the DNA by physically binding with it? Is it the receptor itself or another molecule? When there are secondary messengers, do the secondary messengers bind to the DNA and change it?
In cell signaling, neurotransmitters bind to a receptor on the cell membrane. The receptor then sends a signal to another molecule, which sends a message to another molecule. So the receptor doesn’t directly change the DNA, another molecule does. Those intermediary molecules are called secondary messengers. The final action wouldn’t really be to change DNA, but rather calling a protein to be produced. Thus, the secondary messengers would be telling the proteins responsible for translation.