We must emphasize that even though the vast variety of protein pathways in the cell provides for the functions of life, merely having those pathways does not generate life. Life is dependent upon the precise coordination and regulation of the cell’s protein pathways. The brain and supporting nervous system represent the regulatory mechanism that coordinate all of these many pathways that provide for life.
So . . . where is the cell’s brain? Well, contrary to what you probably know, it’s not in the genes. If you think back to high school or college biology, you probably remember that the cell’s largest organelle, the nucleus, is described as the control center or brain of the cell. Because it was presumed that genes control life and that the genes are housed within the nucleus, it was a no-brainer to assume that this organelle represented the cell’s brain. However, in light of the infamous nature of assumptions, we must question the accuracy of this belief.
Observations from experiments published 80 years ago challenge the assumption that the genes are the brains of the operation. When one removes the brain from a living individual-chicken with its head cut off notwithstanding-that individual dies. But if a nucleus is removed from a cell, a process called enucleation, the cell survives, and many can live for two or more months without their genes! In fact, enucleated cells will continue to function normally until they need to replace protein parts vital to their survival.
Genes are simply blueprints used to make protein parts. Enucleated cells eventually die, not due to an immediate absence of genes, but because they cannot replace their worn-out protein parts and, as a result, they inevitably begin to decay. While traditional thinking has taught us to believe that the nucleus is the cell’s brain, in truth, the nucleus is the functional equivalent of the cell’s gonads, its reproductive system.
This misrepresentation is understandable. Throughout history, science has predominantly been an “old boy’s club.” Because males reputedly think with their gonads, confusing the cell’s nucleus with its brain is, in the light of that bias, an understandable error.
So, if the genes are not the brain, what is? The brain is actually the cell membrane, the equivalent of the cell’s skin. Built into the membrane are protein switches that respond to the environmental signals by relaying their information to internal protein pathways. A different membrane switch exists for almost every environmental signal recognized by a cell. Some switches respond to estrogen, some to adrenaline, some to calcium, some to light waves, and so on.
Although there may be one hundred thousand switches in a cell’s membrane, we don’t have to study each one of them individually, because they all share the same basic structure and function. Following is a conceptual illustration of a genetic membrane switch.
Figure A: Each cell has receptor proteins and effector proteins that extend through the cell’s membrane, connecting its cytoplasm with the surrounding environment.
Metaphorically, these proteins serve as switches
that put the cell’s motor and gears into motion.
Figure B: When the receptor protein receives a
signal from the environment, it modifies its
shape and connects with the effector protein.
Each membrane switch is a unit of perception, comprised of two fundamental parts, a receptor protein and aneffector protein. The receptor protein, as its name implies, receives, or senses, signals from the environment. Upon receiving its primary complementary signal (Primary Signal in Figure B), the now activated receptor moves to and is, thus, able to bind to the switch’s effector protein.
In the illustration on the right, it appears as if the receptor protein and the effector protein are shaking hands (arrow in Figure B). It is this connection that allows information from outside the cell to be transmitted into the cell where it is used to engage behavior.
When activated by a receptor, the effector protein sends a secondary signal (Secondary Signal in figure B) through the cytoplasm inside of the cell that controls specific protein functions and pathways. The coordinated activity of membrane switches enables the cell to sustain its life by orchestrating metabolism and physiology in response to an ever-changing environment.
Receptor proteins provide the cell with an awareness of the elements of the environment, while the switch’s effector proteins generate signals, which are physical sensations that regulate specific cell functions. Together, these switches, located in the cell membrane, provide “an awareness of the elements of the environment through a physical sensation.
That very phrase offers the key to unlocking the secret of life. Are you ready?
Those words are the dictionary definition of perception, a word that’s Latin roots mean “comprehension” or, literally, “a taking in.” Consequently, the protein switches in the cell membrane represent fundamental molecular units of perception. Because these switches control the cell’s molecular pathways and specific biological functions, we can confidently conclude that perceptions control behavior!
Also, dear readers-the fact that perceptions control behavior at both the cellular and the human level-is the realsecret to life!
New-Edge Biology Conclusion #3
Protein perception switches in the cell membrane respond to environmental signals by regulating cell functions and behavior.