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By Root 983 0

the environment. In my own work in the laboratory, I saw over and over the impact a changed environment had on the cells I was studying. But it was only at the end of my research career, at Stanford, that the message fully sank in. I saw that endothelial cells, which are the blood vessel-lining cells I was studying, changed their structure and function depending on their environment. When, for example, I added inflammatory chemicals to the tissue culture, the cells rapidly became the equivalent of macrophages, the scavengers of the immune system. What was also exciting to me was that the cells transformed even when I destroyed their DNA with gamma rays. These endothelial cells were “functionally enucleated,” yet they completely changed their biological behavior in response to inflammatory agents, just as they had when their nuclei were intact. These cells were clearly showing some “intelligent” control in the absence of their genes. (Lipton 1991)

Twenty years after my mentor Irv Konigsberg’s advice to first consider the environment when your cells are ailing, I finally got it. DNA does not control biology, and the nucleus itself is not the brain of the cell. Just like you and me, cells are shaped by where they live. In other words, it’s the environment, stupid.

CHAPTER 3

THE MAGICAL MEMBRANE

Now that we’ve looked at the protein assembly machinery of the cell, debunked the notion that the nucleus is the brain of the cellular operation, and recognized the crucial role the environment plays in the operation of the cell, we’re on to the good stuff—the stuff that can make sense of your life and give you insight into ways of changing it.

This chapter puts forth my nominee for the true brain that controls cellular life—the membrane. I believe that when you understand how the chemical and physical structure of the cell’s membrane works, you’ll start calling it, as I do, the magical membrane. Or alternatively, capitalizing on the fact that part of the word is a homophone for brain, I refer to it in my lectures as the magical mem-Brain. And when you couple your understanding of the magical membrane with an understanding of the exciting world of quantum physics that I’ll present in the next chapter, you will also understand how wrong the tabloids were in 1953. The true secret of life does not lie in the famed double helix. The true secret of life lies in understanding the elegantly simple biological mechanisms of the magical membrane—the mechanisms by which your body translates environmental signals into behavior.

When I started studying cell biology in the 1960s, the idea that the membrane was the cell’s brain would have been considered laughable. And I have to concede that the membrane in those days was a sorry-looking Mensa candidate. The membrane seemed to be just a simple, semi-permeable, three-layered skin that held the contents of the cytoplasm together. Think Saran wrap with holes.

One reason scientists misjudged the membrane is that it is so thin. Membranes are only seven millionths of a millimeter thick. In fact, they are so thin that they can only be seen with an electron microscope, which was developed after the Second World War. So it wasn’t until the 1950s that biologists could even confirm that cell membranes exist. Up until that time, many biologists thought the cell’s cytoplasm held together because it had a Jello-like consistency. With the aid of microscopes, biologists learned that all living cells have membranes and that all cell membranes share the same basic, three-layered structure. However, the simplicity of that structure belies its functional complexity.

Cell biologists gained insight into the amazing abilities of the cell membrane by studying the most primitive organisms on this planet, the prokaryotes. Prokaryotes, which include bacteria and other microbes, consist only of a cell membrane that envelops a droplet of soupy cytoplasm. Though prokaryotes represent life in its most primitive form, they have purpose. A bacterium does not bounce around in its world like a ball in a pinball machine.