The cell is the basic unit that all living things are composed of. As an individual unit the cell is capable of digesting its own nutrients, providing its own energy, and replicating itself in order to produce future generations. Cooperative groups of similar cells form tissues, and a cooperation between tissues in turn, forms organs, the functional units of an organism (Hunter et al.,1996). Intercellular adhesion brings cells together to help perform special needs (Encyclopedia Britannica).

The simplest examples of the ability of cells to recognize and adhere to one another come from organisms that live much of their lives as single cells but form a multicellular aggregate, or gather, for a specific purpose (Hunter and others 1996). For example, when starved, several types of single-cell organisms band together to develop

been injured or damaged. According to Rossman, a family of viruses known as rhinoviruses has developed a backdoor way to use this receptor to enter human cells (Lehrer S., 1998). The Purdue study shows that the rhinovirus bypasses the structure that ICAM-1 uses to bind the white blood cells, and binds instead to another part of the receptor to gain entry into the cell (Lehrer S., 1998). It is said that the virus has probably adapted itself to be able to attach to this particular molecule in humans, so they fit exactly (Lehrer S., 1998). As the virus attaches to one or more receptor sites on a cell, the cell membrane engulfs the virus, wrapping around it and allowing it to come in contact with more receptor sites (Lehrer S., 1998). If the interaction could be prevented, a large percentage of colds in humans could be eliminated without interfering with the normal function of ICAM-1 receptor (Lehrer S., 1998).

4. Lehrer S., editor. 1998. Unraveling How Viruses Enter Cells. USA Today;127:p2-3.

In recent years, the role of adhesion molecules in rheumatic diseases has become the focus of attention. Besides increasing the understanding of cellular interactions involved in inflammation, studies on these molecules have prompted the search for new anti-inflammatory agents which may interfere with adhesion mediated events in the inflammatory process.

the specialized cells needed for reproduction (Hunter et al.,1996). In this process, certain cells at the center of the developing aggregate secrete chemicals that cause the others cells to bond tightly into a group (Hunter et al.,1996). In the case of slime mold amoebas, starvation causes the secretion of a compound, cyclic adenosine monophosphate, that causes the cells to stick together end to end (Hunter et al.,1996). With further gathering, the cells produce another cell-surface glycoprotein with which they stick to one another over their entire surfaces (Unter et al.,1996). The cellular aggregates then produce an extracellular matrix!

Recently, a team of res

Some common words found in the essay are:
Encyclopedia Britannica, Roebuck Finnegan, According Clayton's, Roebuck Finnegan's, , According Rossman, Intercellular Adhesion, Purdue University, S1998 ICAM-1, According Hunter, intercellular adhesion, adhesion molecules, et al1996, hunter et, hunter et al1996, lehrer 1998, finnegan 1999, roebuck finnegan, roebuck finnegan 1999, receptor sites, intercellular adhesion molecule, multicellular organisms, et al, et al 1998, digesting own nutrients,
Approximate Word count = 1373
Approximate Pages = 5 (250 words per page double spaced)