Essentials of Glycobiology—Part 5 (Glycocalyx vs Nucleus)

​The National Academy of Science observed in 2012 that the "elimination of any single, major class of glycans [8 biological sugars] from an organism or cell results in death." And that death is immediate because essential cellular communications are disrupted. Daily operations necessary for sustaining life cannot happen. I used to think the nucleus was the brains of the cell. But scientists can remove a nucleus (a process called denucleation ) and the cell can still live for months. Red blood cells don't even have a nucleus and they live for four months! Without a nucleus, the cell can't reproduce on its own and cannot repair itself because there is no DNA code inside to tell it what to do. Without instructions, it can't perform these functions. But it can live day to day and perform the purpose it was designed for (like carrying oxygen throughout the body until it wears out).

The Nucleus is a Storage Facility

In computer operating systems, there is a concept called a distributed operating system. This refers to an operating system whose software is not located on a main, centralized computer. Rather it is distributed over a collection of independent computer devices networked and communicating together. They are physically separate, but electrically connected. This system can handle all of the required jobs in the same way a single, mainframe computer would. In the cell, the glycocalyx represents the distributed operation system. One cell can have nearly one million individual glycoprotein cell receptors capable of engaging with outside input and responding in a programmed way. The nucleus serves more like a storage center or hard drive. It houses the DNA, the genes that contain the instructions or blueprint for running the cell properly. But the nucleus cannot initiate action. It cannot cause the acting upon or reading of any part of those instructions. It has to wait for outside input. What causes the blueprint to be read and the building to be built at the right time and place is an environmental input generated from outside the cell. Something above the genes has to turn the genes on or off. An entire science called epigenetics (above the genes) has risen to explain how genetics (the genes) activate.

The Glycocalyx Makes Life Happen

When cell receptors on the glycocalyx receive signals from molecules in the interstitual fluid (fluid outside and surrounding), decisions and actions are initiated inside the cell. A conformational change (a bending or electromagnetic reorientation) of the antenna results from the binding of an exterior molecule to the outside glycoprotein cell receptor. Proteins on the interior portion of the glycoprotein become exposed; they are then read by interior molecules which go into the nucleus to read and copy the instructions for what to do next. Specific metabolic processes are thus initiated and the appropriate interior response to the exterior input is generated. Compared to a keyboard, messages are conveyed from the outside of the computer to the inside of the computer and the correct output occurs. It is a simple, beautiful, and amazingly elegant demonstration of how life is sustained within our bodies.