Compare and Contrast the Nature and Action in Metabolism of Several Secondary Messengers

Role of Secondary (Hormone) Messengers in the Process of Metabolism in Cellular Communication As the primary unit of human living, cells have multi-function tasks that need to be accomplished spontaneously within the body, especially if the body needs to accomplish many tasks and activities at the same time. That is why cells have an elaborate form of communication, which is primarily chemical and biological in nature. The biochemical cellular communication in cells coordinates all tasks that are essential for the survival of the human body.

These tasks include cell communication for motion and active transport of substances within the body; biosynthesis, or the production of chemical substances as a result of the biological activities of the cell; cell reproduction, growth, and death; and signal amplification, which is one of the primary phases in the process of cellular communication. The signal amplification phase, apart from acting as an 'intermediary' phase towards the accomplishment of a particular biochemical activity, is also considered the catalyst towards the production of secondary messengers.

Secondary messengers are actually messenger molecules produced to diffuse themselves within a cell, which, in turn, reacts to change its activities in accordance to the biochemical response appropriated by the messenger molecule (CSS, 2002). Messenger molecules enter the cell through the cell membrane, and bind itself, upon entering, into a nuclear receptor protein. However, messenger molecules can also alter a cell's activity simply by binding itself to a receptor present in the cell membrane.

As the messenger molecule binds itself with the receptor, the latter changes shape, which inadvertently changes also the cell's activities. The entry of messenger molecules into the cell can be best described as the primary event leading to cellular communication, and later, into more complicated cellular activities. The second event concerns the production of secondary messengers, which became the primary participants in cell communication, since they amplify signals previously generated in the primary event (i.e., messenger molecules activating receptors in the cell membrane) (Biology Pages, 2003).

In the second event of cell communication, hormones that bind themselves in the cell membrane receptor produce secondary messenger molecules. Once a reaction occurs between the hormone and the receptor, secondary messenger molecules are produced. ATPs, or adenosine triphosphate molecules, which serve as the 'fuel' for most of the cellular activities, are converted into secondary messengers. These secondary messengers are of the following, depending on the reaction elicited during the secondary event: cyclic nucleotides or cAMP, inositol triphosphate or IP3, and calcium ions or Ca++ (Ca2+) (Microsoft Encarta 2002).

According to the Biology Pages web site, these secondary messenger molecules have specific functions that are significant in the process of cell communication. The first enumerated secondary messenger, cyclic nucleotides or cAMP, are generated through the following hormones: adrenaline, glucagon, and luteinizing hormone or LH. Cyclic AMPs (cAMPs) are essential for the production of adrenaline or energy for the activities of the cell. These cell activities include transmission of nerve signals, movement of the muscles, synthesis of protein, and cell division.

Glucagons, on the other hand, utilize secondary messengers in order to transmit signals pertaining to essential cellular activities such as maintaining a normal blood-sugar level and production of glucose from amino acids. Lastly, cAMP serves as the catalyst for the secretion of hormones by the pituitary gland, which promotes human growth and controls the water balance of the body.

Inositol triphosphate or IP3, binds receptors on the endoplasmic reticulum, and upon activation, conducts activities such as the manufacturing, processing, and transportation of substances from the cells to other parts of the body, and vice versa. Furthermore, IP3s also makes possible the process of protein synthesis, and the process of storing fats that are later converted into chemical energy. Lastly, Ca++ ions are generated by the activation.