March 26, 2023
Thoughts on mysteries
Every now and then I reflect on the miracle of life. Not that I really believe in miracles – they are a human fictional invention. As many physicists have agreed upon it is very difficult to define what is living and what in not. Webster defines life as: an organismic state characterized by capacity for metabolism, growth, reaction to stimuli, and reproduction. NASA’s scientists define life with eleven words: “Life is a self-sustained chemical system capable of undergoing Darwinian evolution”.
Even sexual forms of life often have exceptions such as the Amazon mollies. male of a closely related species, but the sperm only triggers reproduction and is not incorporated into the already diploid egg cells the mother is carrying (except in extraordinary circumstances). This results in clones of the mother being produced en masse. This characteristic has led to the Amazon molly becoming an all-female species. In some ways the mollies remind me of viruses in that they commandeer living cells to make more copies of themselves.
For most of mankind’s history life was giving a supernatural beginning and many saw living things as containing some magical substance. By my lifetime only the ignorant belonged that idea that life is supernatural.
Life is a chemical-based phenomenon that follows the laws of physics. What the first simple life looked like or how it came to being has not been determined. What is obvious from studying biology is that once life got started it evolved into ever increasingly complexity.
Life does this by creating ordered complexity in a universe that thanks to the second law of thermodynamics is becoming more disordered. Life is a pocket of order in a cosmos of disorder. Eventually, all living individuals do succumb to disorder – a state we call death.
While something is alive it can take energy and use that energy to create more life. Energy is the mechanism that allows chemical systems to build or tear down molecules for the purpose of continuing a homeostatic.
Even more amazing as living systems have become more complex certain properties have been harnessed by life to thrive. The ability to move within its environment is one of the first properties it developed. Probably the most amazing ability of life is to have a brain capable of processing stimuli from other groups of organized cells (eyes, nose, ears, skin, etc.) to keep itself safe in its environment. To have cells organize to create the property of consciousness evokes a feeling of the miraculous within my mind, but consciousness is just a way to increase an organism’s chances to survive.
Energy paths and control is another property of life on the cellular level. Much of the success of life is to take advantage of the proton gradient. As stated in Wikipedia: Chemiosmosis is the movement of ions across a semipermeable membrane bound structure, down their electrochemical gradient. An important example is the formation of adenosine triphosphate (ATP) by the movement of hydrogen ions (H+) across a membrane during cellular respiration or photosynthesis.
An ion gradient has potential energy and can be used to power chemical reactions when the ions pass through a channel (red).
Hydrogen ions, or protons, will diffuse from a region of high proton concentration to a region of lower proton concentration, and an electrochemical concentration gradient of protons across a membrane can be harnessed to make ATP. This process is related to osmosis, the movement of water across a selective membrane, which is why it is called "chemiosmosis".
The cells ability to move protons in order to power the ATP mechanism gives the cell the energy it needs to run cellular processes. The proton gradient is one of the key differences between life and non-life.
It is by the cells ability to create order and take advantage of energy that life exists on earth. The passing of time is a fickle thing for humans to understand. We are very fuzzy when it comes to understanding the power of time to allow simple systems to become complex systems. Humans also don’t fully appreciate how energy allows atoms over time to organize to become living systems. How cells function within the human body is still not fully understood. Indeed, that is an understatement. The failure during my lifetime to understand how atoms that make up cells that form the human brain that allows thought and emotions if a frustration to me. I would love to know how the brain functions.
I hope life someday will reveal her secrets to our minds that we can better understand our cosmos and ourselves.
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