Thus far, our discussion of cellular energy production has focused upon strategy (an alternation of energy and entropy) and the necessity of specific enzymatic assistance. Most recently we focused upon glycolysis, a universal energy producing process that is employed by all cells including bacteria. While an essential feature, it is not part of the Big 2, photosynthesis and cellular respiration. Let us now turn our Attention to photosynthesis.
The end result of photosynthesis is Life’s building block bio-molecule, G3P. Depending upon which metabolic pathway it enters, G3P can be transformed into biomass or bioenergy – glucose or ATP molecules. By itself G3P is useless to the cell. Only after it is transformed over time does it become useful to the cell.
Photosynthesis consists of two stages – a light reaction and a dark reaction. In the light reaction, a chlorophyll molecule’s electron is charged with solar energy. The excited electron is passed on to the dark reaction. In this reaction, the electron’s heightened energy is employed to capture a carbon atom, which becomes part of a G3P molecule.
However, the chlorophyll molecule who donated her electron in the service of the whole is incomplete. Craving to be complete again, she grabs an electron from a nearby water molecule. Called hydrolysis, this critical water-splitting process enables the chlorophyll molecule to continue fulfilling her function, thereby allowing photosynthesis to continue producing G3P.
Hydrolysis splits the water molecule into an electron, oxygen and a proton. The electron completes the chlorophyll molecule; the proton is employed to generate ATP molecules that power the dark reaction; and oxygen is given off as a waste product into the atmosphere. Yet the story does not end here.
Due to the prevalence of photosynthesis on our planet, oxygen is a key ingredient in the Earth’s atmosphere. Oxygen drives cellular respiration, the cell’s other energy production process. Without oxygen from the atmosphere, cellular respiration comes to a halt. Without cellular respiration, all multi-cellular life forms that exist on land, including plants and animals die. In such a way, hydrolysis and its components play essential roles for our planet’s dominant life forms.
However, there’s more to the hydrolysis story. Originally, a hydrogen molecule (not water) donated his electron to the deficient chlorophyll molecule – therefore no oxygen into the atmosphere. Without oxygen, the earliest life forms evolved anaerobically, but with less available energy. Then cyanobacteria discovered a way to employ water as an electron-donor for hydrolysis. As a waste product for this more productive process, oxygen accumulated in the atmosphere. While this development proved to be an oxygen-catastrophe for the anerobic life forms on land, it enabled the evolution of even more complex life forms, including us.
I am awed by the many unsolvable mysteries associated with photosynthesis: 1) Photosystems that somehow capture solar energy, rather than dissipate it (as is usual). 2) Electrons that are transported elsewhere to produce necessary energy work. 3) Deficient chlorophyll molecules that grab an electron from a nearby water molecule to continue the process. 4) Losing an electron, the water molecule splits into its components, each of the which become an essential part of the photosynthetic process. How could atomistic matter possibly self-organize via random collisions into this holistic system with so many mutually interdependent parts?
The indivisible, complex unity of the single cell recommends a Divine Creation. However, I’m not attempting to persuade you of this possibility, as you’ve already made up your mind. Rather than attempt the impossible, I’m merely suggesting that the cell’s many miracles open the door for another miracle – Life's Information Digestion System. Our ID system exists in another temporal dimension and posesses both a holistic/temporal sense and computational capabilities. Hallelujah! Let us bow and worship the Almighty!
Recap: Cellular Processes indicate that Living Systems are Holistic
Photosynthesis’ Endproduct = Life’s building block molecule: G3P
Chlorophyll’s Craving to be Whole & Belong enables her to Split a Water Molecule
Hydrolysis => Land Plants & Animals + Life’s Substance & Sustenance
Hydrolysis & its Momentous Influence upon Evolution
Awe & Wonder concerning Photosynthesis & Cellular Energy Efficiency
If Cellular Energy Production, why not Life’s ID System?
Recall from the first chapter that virtually all living systems rely on photosynthesis and cellular respiration to produce and store bioenergy. These two processes are symmetrical, as their chemical equations are nearly exact opposites of each other – shown below.
6H2O + 6CO2 + Solar Energy = C6H12O6 + 6O2
C6H12O6 + 6O2 = 6H2O + 6CO2 + Biological Energy
We also explored how all cells regularly employ entropy in a strategic manner. They first utilize stored bioenergy to push chemical reactions uphill, then rely on entropy to naturally pull chemical reactions downhill. The process can be likened to a bicyclist exerting muscle power to go up a hill and then coasting downhill. Cells use this strategy to produce both biomass and bioenergy. They also alternate energy and entropy to transport essential ingredients and energy along their metabolic pathways.
The second chapter examined glycolysis, the first step in cellular energy production. All cells, including bacteria, employ this metabolic process to produce bioenergy. Glycolysis employs 2 units of stored bioenergy and then entropy to store 4 units of bioenergy. Cells then use this stored bioenergy to drive cellular respiration, which produces more than 30 units of stored bioenergy. Each of the stages requires a unique enzyme to catalyze the chemical reaction.
The sole purpose of each of these complicated processes, ingredients and strategies is to serve the entire cell. Further, cell utilizes the end results of each process, not instantly, but in the future. Rather than immediately consumed, both bioenergy and biomolecules are stored for later use.
These realities indicate that living systems are holistic and require a sense of time. In contrast, material systems are atomistic and have no temporal sense. Due to this system and temporal disparity, a material explanation for Life’s holistic behavior is not only improbable it is impossible. This chapter continues these themes via an examination of the details of photosynthesis. This crucial metabolic process infuses inanimate matter with solar energy to generate the biomolecule that is the building block of biomass and bioenergy.
Photosynthesis produces biological substance and sustenance. For Life, these are one and the same. The substance of plants, e.g. grains and vegetables, and animals, e.g. chicken and pigs, become our sustenance, our food. Indeed, virtually everything we consume was once alive.
Photosynthesis converts Carbon Dioxide and Water into Glucose and Oxygen. The process requires energy because it transforms simple low energy, inanimate molecules into complex high energy, organic molecules. These high energy organic molecules become our substance and our food. Photosynthesis employs photons from the sun (solar energy) to power the process. The solar energy is used to push these chemical reactions uphill.
Photosynthesis has two stages: the light and dark reactions. The light reaction converts solar energy into biological energy. The dark reaction employs this BioEnergy to create the first stage of BioMass – the aforementioned G3P molecule. This versatile molecule can be converted into glucose or a variety of other organic molecules. As an indication of the mutual interdependency of cellular products, glucose is the fuel of glycolysis, hence cellular respiration.
Let us examine each of these processes in turn. In the first stage of the light reaction, photons from our Sun excite the electrons in chlorophyll molecules. This is not unusual in and of itself. Many molecules are excited by solar energy. Witness sunburns and skin cancer. What is unusual about chlorophyll molecules? They belong to a photo system.
The group of chlorophyll molecules in the photo system pass the electron’s energy back and forth amongst themselves until they can pass it along to a receptor molecule. The excited electron in the receptor molecule is converted into the Bioenergy that powers the dark reaction – the second stage of photosynthesis.
The dark reaction is also called the Calvin cycle. In the first step, a carbon atom is cleaved off from a carbon dioxide molecule. The carbon capture is achieved due to the talents of an incredibly large enzyme, rubisco - more than 60 protein subunits.
As an indication of the importance of this step, the incredibly complicated and large mega-molecule rubisco is the most prevalent enzyme on the planet. Virtually every plant contains this amazing biomolecule.
The captured carbon atom is joined with a 5-carbon molecule to form a 6-carbon molecule. After adding some of the ubiquitous phosphate groups, the 6-carbon molecule splits into two 3-carbon molecules, G3P. G3P is the end product of the Calvin cycle. This is the highest energy molecule in the cell’s energy producing metabolic pathways. As such, all subsequent reactions with G3P run downhill; they require no energy.
Some G3P molecules are used by plant cells to generate more 5-carbon molecules to start the Calvin cycle over again. The rest can be used for energy or substance depending on which metabolic pathway they take. If this extraordinary molecule takes one path, G3P can be converted into glucose via a few enzymes – no energy required. If G3P enters the glycolytic pathway, it can both generate energy in the form of charged ATP molecules and also be converted to Pyruvate, the fuel for the Krebs cycle, the first stage of the highly productive cellular respiration process. An amazingly high energy and versatile molecule, G3P can go both ways.
Summarizing: Photosynthesis employs solar energy to create the high energy, organic mega molecule G3P from the low energy, inanimate molecule carbon dioxide. Quite an amazing trick! As the source of BioEnergy and BioMass, G3P could be called Life’s building block.
Our scientists can’t accomplish this magic. They continue to be baffled by Nature’s wonders.
Bow your head and pray to the higher powers that have generated such wonder. Random? Divine Coincidence of Providence? Probably a bit of both.
More debris thrown at the cliff.
Hopefully something will stick.
The Light Reaction of Photosynthesis begins with individual photons hitting a cellular receptor filled with chlorophyll molecules. The receptor, shaped somewhat like a radar receiver or a satellite dish, is perfectly designed to capture and concentrate solar energy that comes in the form of photons. This so-called photo system is contained in the chloroplast. Found in plant cells, the chloroplast is the organelle that is responsible for photosynthesis.
Where did this photon receptor (the photo system) come from? Random events or divine coincidence? No one knows. As a top molecular physicist noted, “It seems that evolution required a little help.” As there is no conclusive evidence one way or the other., the explanation one chooses seems to be a matter of personal preference.
Whether originating from impersonal or intentional sources, this so-called photo system is certainly an amazing apparatus. The photo system first captures the solar energy in the form of an excited electron. Then the system concentrates this energy - exciting the electron more and more. Eventually the chlorophyll’s electron becomes so excited that it jumps ship into a specially designed receptor molecule.
During this crucial process, a chlorophyll molecule loses one of her electrons, the one that became excited by the Light. Without this electron, the chlorophyll molecule is unable to participate in the group activities of its photo system. Desperate to belong, the deficient chlorophyll molecule strips an electron from a water molecule that happens to be nearby.
Actually, the plant’s root supplies the water. Without water, the chloroplast’s photo system shuts down and with it the ability to convert solar energy into biological energy. Without this crucial ability, the plant dies. For this reason, we water our gardens. The water gives up its electron so that plants and hence animals can live.
After stripping away the water molecule’s electron to replace the electron lost to the photosystem’s receptor molecule, our chlorophyll molecule can join in the fun and games. Life can literally go on.
Let us think about the water molecule’s fate. It has been split in half by the chlorophyll’s craving to belong. Having lost an electron in service of the whole, the chlorophyll molecule was excluded from the photo system. No gratitude. Desperate to replace her missing electron and rejoin the party, the chlorophyll molecule splits a water molecule, a process called hydrolysis (water-splitting).
Have you ever attempted to split a water molecule – grab one of its electrons to fulfill your deficiencies? Probably not.
Water molecules are tightly bound. The bonds between electrons and protons are really strong. This is why water is virtually indestructible under normal circumstances. But the deficient chlorophyll’s yearning for completion and belonging was so great that she, of all molecules, was able to split water’s high energy bonds apart.
And how did she lose her electron? Recall the solar energy excited and concentrated her electron so much that it was able to jump to another molecule to become part of an electron transport chain – more later.
The chlorophyll’s electron must have been even more tightly bound than the water molecule’s electron. Otherwise the deficient chlorophyll molecule would not have enough potential energy to strip the replacement electron from the water molecule.
The solar energy that liberated the chlorophyll’s electron must be even greater still. The accumulation of photon energy must be extraordinary in order to excite the chlorophyll’s electron so much that it jumped from one high energy molecule to an even higher energy molecule.
This seemingly impossible task set up a chain of events that includes many significant events. On the most immediate level, the concentrated solar energy enables the 1) splitting of the water molecule and 2) storing the excited electron’s energy for later use.
When the water molecule is split by the craving of the deficient chlorophyll molecule for completion, there are three byproducts: oxygen, an electron and a proton (from water’s hydrogen molecule). Each are incredibly significant.
As mentioned, the electron goes to the chlorophyll molecule. This additional electron allows the photosynthesis process to continue.
When the chlorophyll cleaves off water’s electron, water’s oxygen molecule breaks away from the hydrogen molecule. The oxygen molecule leaves the photosynthesis process as a waste product and enters the Earth’s atmosphere. This oxygen accumulated over millions of years. The oxygen rich atmosphere allowed land animals like us to evolve.
So water’s electron recharges the all-important photosynthesis process. Water’s oxygen enables Earth’s land animals to exist. The third byproduct of hydrolysis is hydrogen without an electron – a hydrogen ion or simply a proton.
This proton is forced into the inside of the thylakoid, a structure inside the plant cell’s chloroplast. Eventually when enough of these positively charged protons accumulate, a strong gradient is established between inside and outside. An enzyme, ATP synthase allows the protons inside the membrane to rush outside to balance the charges. This process, chemiosmosis, generates enough energy to recharge many ATP molecules. These charged molecules are used in the dark reaction to create G3P. As seen, G3P is a 3-carbon sugar that is the basis of virtually all living substance and sustenance.
So hydrolysis, i.e. water splitting, has 3 important functions: 1) recharges chlorophyll so that photosynthesis can continue; 2) releases oxygen into the atmosphere which allows land animals like us to survive, and 3) yields a proton that drives the production of ATP, the energy currency of all life forms on Earth. Pretty significant. For these reasons, some say hydrolysis is the most important stage of photosynthesis.
However, every stage is essential. For instance, the splitting of the water molecule was possible only because solar energy in the form of quantized photons excited the electron of the chlorophyll molecule so much that it broke its bonds to join a new molecule. In desperation due to lacking a vital member of her quantized energy family, the chlorophyll grabbed an electron from an adjacent water molecule thus splitting her in half – thereby simultaneously creating the essential byproducts that enable life on land, i.e. living substance and sustenance. Wow!
However, it has not always been this way. In the beginning there were other molecules, besides water, that donated their electrons and protons to the photosynthetic process that enables Life.
After aqueous asteroids and meteors collided with the surface, the Earth came to be the watery planet that we know and love. This occurred about 4.6 billion years ago. The first evidence of Life is 3.5 billion years ago and the first evidence of photosynthesis, shortly after at about 3.4 billion years ago. So photosynthesis was part of the prokaryotic bacteria’s energy toolbox from very close to Life’s beginning.
However, the first light reactions of the photosynthetic process were anoxygenic in that they didn’t use water that gives off oxygen as a waste product. Rather than water, hydrogen and hydrogen sulfide gave up an electron and a proton to the light reaction of green and purple sulfur bacteria. With no oxygen produced in photosynthesis, the early Earth’s atmosphere was thin and unprotected. Life was confined to vast oceans.
It took nearly another billion years for evolutionary processes to take advantage of Earth’s abundant supply of water in the photosynthesis process. Cyanobacteria were the first life form in which water donated an electron and photon to photosynthesis and gave off oxygen as a byproduct. This step had momentous consequences. Evolutionary biologists have deemed this transition the oxygen catastrophe.
Due to the success of oxygenic (with water) photosynthesis, oxygen began accumulating in the atmosphere. Eventually, this accumulation led to oxygen rich air close to the surface with an ozone layer above.
The ozone layer acted like a type of skin, a sunscreen, as it protected and protects living forms from the destructive effects of solar radiation. Created by the oxygen released in the relatively late process of oxygenic photosynthesis, the ozone layer enabled Life to move from the Ocean onto Land.
However simultaneously, the oxygen-rich atmosphere was destructive to many of the earliest life forms. Oxygen is an electron hog, as we shall see, and stole electrons from the organic molecules. Without protection, this oxidation process led to mass extinctions of many life forms – hence the term catastrophe.
The first evidence of oxygen-producing cyanobacteria is from about 2.7 billion years ago. The first evidence of oxygen in the atmosphere is between 2450 – 2320 million years ago (Ma) during the Paleoproterozoic era. Cyanobacteria were the primary oxygen producer on the planet for 2 billion years from 2500 Ma to just recently at 543 Ma - the entire Protoerozoic Eon. As a testament to the success of this particular life form, nearly 3 billion years after their first appearance upon the stage of life, cyanobacteria remain in the top three oxygen producers. Blue-green algae and land plants finally passed them up.
By 1200 Ma, the red and brown algae became more structurally complex. Then 750 Ma, the blue green algae began to outproduce oxygen in strong sunlight in shallow water. The first land plants, like mosses, occurred 475 Ma and the first vascular plants 423 Ma. These land plants now produce over half the oxygen in our atmosphere with the rest still coming from cyanobacteria and algae.
There are few points to take away from this section. 1) The complex, nearly miraculous photosynthetic process occurred very early in Life’s evolution, just 100 million years after the first living systems emerged nearly 4 billion years ago. As a comparison, it took nearly 2 billion years for multi-cellular organisms to evolve and 3 billion years for land plants to evolve.
2) It was another billion years after Life’s creation before cyanobacteria evolved a photosynthetic process that employed water as an electron donor rather than hydrogen. This momentous development led to an oxygen rich atmosphere with an ozone layer that enabled the evolution of land plants and animals.
Before proceeding forth, let us first express some awe and wonder concerning photosynthesis and cellular energy efficiency. Photosynthesis has two stages - the light and dark reaction. The light reaction of photosynthesis converts solar energy into a form of energy that cells can utilize. Put succinctly, the energy of photons is transferred to electrons. A quantum of solar energy becomes a quantum of electrical energy. Amazing in and of itself. Whoa!
While miraculous, this process does no real work. The solar-electrical energy is stored for immediate, but controlled use in the subsequent processes of the dark reaction – carbon capture and the Calvin cycle. In other words, the dark reaction is dependent upon the light reaction. Without the energy from the light reaction, the dark reaction cannot perform its primary function – placing an inanimate carbon atom into the biomolecule that is the foundation of bioenergy and biomass. Wow!
Am also blown away by the cell’s strategic use of energy. The cells that make up our body and every other body are not proliferate spenders, but are instead very parsimonious in their use and production of energy. Everything is tightly controlled – just the right amount of this and that – recycling molecules, electrons and protons when possible. No throwing energy around, rather careful and well planned out expenditures – nothing random here. While entropy is always at work, the cell employs him in tricky ways to serve her needs.
Awestruck, I must again bow my head and express gratitude to the Creator of this complexity!
Why am I going on and on about the miraculous qualities of the cell? Multiplying example upon example of extraordinary structure and process, such as photosynthesis with hydrolysis and cellular respiration with glycolysis. Due to the inner connectivity and mutual dependency of these cellular systems, it is hard to imagine how they could have come about through purely random mutations.
Perhaps random with a divine nudge occurring here and there – pushing everything in the right direction to eventually create a life form, us, that is conscious of self and its place in the Universe. With awe and wonder able to ask the questions – Why did this happen? and What is going on?
Is this lengthy exposition just a way of supporting the theory of Divine Creation?
Probably not. There is no real hope of persuasion.
For the most part, people have made up their minds – one way or the other.
Rather, these incredibly complex and detail-oriented cellular energy producing and storing factories make space for the miraculous nature and existence of our ID system – our image overlay process – its dynamic and ongoing relationship with data streams that is modeled by the mathematical logic of DSD.
The origination of the cell’s amazingly complex metabolic pathways remains a mystery. For instance, no one knows how the cell’s mutually interdependent energy production systems came into being. Electron transport chains, chemiosmosis, and glycolysis (each step in every process assisted by its own enzyme) are all required to recharge ATP, the storage battery of all living systems. The sole purpose of each system is to serve the whole cell. How could have self-absorbed atomistic Matter evolved into these intricate holistic systems, each with its own enigmatic miracles?
If all these miraculous living processes that occur in nearly every cell can exist without a plausible origination explanation, then why not my ID model? Especially as it employs familiar verbal constructs, i.e. mental energy, Feelings and Consciousness, albeit in a more specific technical way.
Ah well.
Yelling into the Wind.
Yearning to make an Impact.
Hope springs eternal.