Tunable interplay of self-communication and neighbor communication enables cells to span a diverse repertoire of cellular behaviors. ~ cytologists Hyun Youk & Wendell Lim
Cells are the atoms of life. Both are organized on energetic relations.
Similarly, cellular communication is analogous to the dynamics of inorganic existence; the relations between subatomic particles, and between atoms in molecules. There is continuous interaction in all instances.
Cell polarity is critical for the specialized function of the vast majority of cells. ~ American molecular biologist Rong Li
Electrical potentials provide beacons of cellular organization and status. Cells construct polarity to facilitate spatial orientation within, allowing parts of a cell to understand where they are in relation to others.
To engender polarity, enzymes carefully arrange phospholipids, which are a major component of cell membranes. This alters the map of electric charges in a cell, helping shape a coherent terrain for cellular molecules to comprehend. Besides their structural role in assisting intracellular molecular orientation, phospholipids facilitate intercellular signaling.
Subatomic particles form an atom via communication. Bosons urge fermions into coherent relations. Intracellular communication functions similarly.
In organisms, biomolecules, such as proteins, are not just conglomerated atoms. They are a continuing community: in constant communication with each other.
Multicellular bodies also function as a society. Cellular actions and interrelations often follow rules of economy, just as molecular bindings and interactions adhere to their own set of energetic conventions.
Cells communicate within and without. Every cell has its own internal network. Outside is an external network: the cacophony of the neighborhood to which a cell belongs, as well as long-distance missives from conspecific cells.
Conspecific refers to the same type or species. Interspecific is of different species or varieties.
Membrane signaling is fundamental for almost all aspects of life because that’s how information gets from outside cells to inside cells. ~ American biochemist Adam Cohen
Elaborate sets of communication channels and protocols exist in all cells: to track events within, to procure supplies and avoid hazards from without, to fight invasion, to grow, divide, repair, to pick up on neighborhood news, and receiving marching orders to serve an organism’s greater good. Cellular communication is part of a gyre of information gathering and retention, frequently leading to decisions that initiate a new round of communication.
A cell never loses its sense of self, but its mandate is to serve its organism rather than just its own needs. Without this, eukaryotes could not develop and function, nor prokaryotes socially aggregate to greater success than individuals could ever achieve.
Cells in a multicellular organism are often not symmetrical. The cells in an animal’s intestines, for instance, need to know which side faces into the intestines, and which faces out, toward the rest of the body. This requires coordination and communication, both with neighboring cells and within, for the cell to allocate resources and process operations in the right place at the right time. Different genes are expressed in different parts of a cell to accomplish this.
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Cell signaling comprises the complex set of communication protocols that cells employ for messaging, whether within or without. In its vast diversity, cell signaling is easily one of the most intricate realms in biology.
Signal transduction defines the 2-step process of intracellular communication. 1st, an extracellular signaling molecule activates a receptor on a cell surface.
Surface reception prompts creation of another molecule, termed a 2nd messenger, which carries the signal to a target molecule within the cell; often, either in the nucleus or cytoplasm. Reception of the 2nd messenger within a cell organelle typically eventuates in a response.
Prokaryotic cellular communication is similar, though the intracellular receiver is not an organelle.
Each cell type has its own language, appropriate to its lifestyle. Cell nomenclature also includes vocabulary that is understood by other cell types, including other organisms.
The energy economics of evolution practically dictate the forms that cell signaling take, though biochemical communications have evolved context: how a specific signal is to be interpreted.
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As all eukaryotes are symbiotic, different species being able to communicate at the cellular level is essential. Consensual communications often lead to concerted actions.
In humans, commensal bacteria help keep the body in pathogen-pounding condition. Bacterial signals influence immune cell training and warn of invasion. They even fight infectious agents. The reason they do so is self-interest: invading pathogens are competition for limited resources and can wreak havoc upon the shared homestead.