Control

We are all subject to control. We have laws that limit what we can do and that stipulate what we may do. And our religion lays down the tenets that we must adhere to and tells us what consequences we will suffer if we don’t. Our parents teach us proper behavior, reinforced by the efforts of our early teachers. All this is supposed to maintain order in our society, both local and global. Without order, life would be chaotic — something that most of us would rather not have.

Controls may be very simple, or very complex. 

When two atoms, or molecules, in isolation react with each other, the reaction is controlled by very simple factors. One is temperature. A higher temperature will cause the atoms, or molecules, to move faster and thereby increase the probability that they would meet and interact with each other. Another is volume. If enclosed in a smaller volume, movement would be more limited and the chances of meeting would be higher. Another is pressure, with easily imagined effects. 

In the presence of other entities, like other atoms, or other molecules, things get a little more complicated. The reaction could be enhanced, or may even be prevented.

As animals and plants evolved, things got really complicated. The chemical reactions, the interacting entities, and the factors that affect those reactions became increasingly more numerous and more complex. Let us see some of what Nature has done to control the increasingly more complicated processes that keep organisms alive and functioning properly.

The simplest living organisms, the bacteria, have walls that isolate the atoms and molecules that are needed for the essential processes that maintain life. And the walls are built to be very selective in what is allowed in and what is allowed out, and special structures are built into the walls to accomplish this. And inside its cell, a bacterium makes molecules that control to a fine degree the reactions that are critical to its life and well-being.

But Nature did not stop with bacteria and other unicellular organisms. Multicellular organisms arose and with them came more intermolecular interactions, as well as intercellular interactions, needing more controls. And the interactions between cells — and the controls — became more complex when the different cells assumed different roles. 

Fast forward to humans. We are a very complex organism, so that there is a lot of controlling in our biology.

Take our immune system, for example. To protect ourselves from harmful organisms that manage to infect us — and from the harmful substances that they may produce — we have cells and molecules that destroy, or otherwise neutralize, those organisms and their toxins. But how does our immune system recognize that those organisms, or their toxins, do not belong in our body? Simple, we have a built-in system that recognizes our own cells and molecules, so that anything that does not belong in our body is recognized as “foreign” and is eliminated. (Saying that it is simple is a gross under-statement. Many cells and many molecules are involved in the recognition of “foreignness.”) There are exceptions, like food, which our immune system usually tolerates. (We have other ways of getting rid of food that disagrees with us.)

There are many more instances of control that our body exercises to maintain order in our very existence.

One truly notable case involves the sex chromosomes. The females of our species have two X chromosomes (the males have one X and one Y). The genes in the sex chromosomes, like in the other chromosomes, code for protein. Having two Xs in females could present serious problems, like the over-production of certain proteins. To prevent this, one X chromosome is “inactivated,” i.e., rendered inutile. 

In most instances, not an entire chromosome is inactivated — only certain genes. The way it is done is a reflection of how complex human biology has become and how elaborate the controlling mechanism has evolved.

Our genome is made up of three billion base pairs, but we use only about 1.5 percent of those for protein production — a seemingly utter waste of genetic material. (In contrast, viruses utilize much more of their genetic material for protein production; for example, 95 percent of the genetic material of the Phi X 174 virus is protein-coding.) So, what is the rest of our genome used for? Ah, most of it is used for control.

Short fragments of RNA are made from those non-coding gene segments. Those small RNAs bind to protein-coding genes thereby interfering with the transcription of those genes, or they bind to messenger RNAs thereby interfering with their translation to protein, or they bind to gene promoters thereby inducing protein production. Clearly, those small RNAs are used to control the production (when and how much) of the proteins and the other molecules that we need for the proper functioning of our body. It is a very elaborate and exquisite system of controls that came with our evolution as humans. We are what we are because of those controls — and we should be thankful for them.

But not all controls are for a good purpose. Dictators, for example, subject a whole nation to their absolute control, forcibly imposing their will on the populace. Such control is not for the good of anyone but the dictator’s and his cohorts’. 

And some individuals try to control others, simply because they are “controlling.” Indeed, some of us have controlling spouses, or controlling parents, or controlling friends. 

Maybe, being controlling is just a reflection of the controlling that is constantly happening in our cells? Maybe, if someone complains that you are a controlling person, you could say “I can’t help it. It’s in my genes!”?

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Eduardo A. Padlan was a research physicist at the US National Institutes of Health until his retirement in 2000. He serves as an adjunct professor in the Marine Science Institute, University of the Philippines Diliman, and is a corresponding member of the NAST. He may be contacted at [email protected].