They bind to receptors on the plasma membrane which generates a signal inside the target cells. Second messenger chemicals activate other chemicals to cause the response. They are whole proteins, consisting of shorter chains of amino acids or simply versions of single amino acids. A protein hormone acts as a “first messenger” by delivering a message from the cells of a gland to membrane receptor sites on the target cells. The interaction between the hormone and the receptor site is often compared to fitting a key into a lock. After a hormone attaches onto a receptor site, chemical reactions occur and activate second messengers. These mechanisms provide communication between glands and target
They bind to receptors on the plasma membrane which generates a signal inside the target cells. Second messenger chemicals activate other chemicals to cause the response. They are whole proteins, consisting of shorter chains of amino acids or simply versions of single amino acids. A protein hormone acts as a “first messenger” by delivering a message from the cells of a gland to membrane receptor sites on the target cells. The interaction between the hormone and the receptor site is often compared to fitting a key into a lock. After a hormone attaches onto a receptor site, chemical reactions occur and activate second messengers. These mechanisms provide communication between glands and target