Life in the Cell Begins at the Edge of Death, Part I: An Essay on the History and Science of Metabolic Science and Nutrition, Fuel Substrate Utilization, and Biochemistry
“Well, you’re pretty good ol’ son, but sit down in that chair right there and let me show you how it’s done.”
Johnny’s instructions to the Devil, before he won his golden fiddle.
Part 1: Vinegar is the Only Fuel for Metabolism*
*See my reply to comment # 1 if you are attempting to refute or disagree with this.
I’m going to show you the only way the human body uses food as fuel, which comes down to knowing the body burns only one fuel. This fuel is vinegar – technically called acetic acid.
About acetic acid: You drink acetic acid when you drink kombucha. After you eat and food moves past your stomach, the gut flora living in your intestines transform specific types of carbohydrates into acetic acid; most of this is immediately burned. Then much later, deeper at the cell level of your body, acetic acid fuels metabolism.
Seeing metabolism work in plain and simple physical terms starting from the sequential breakdown of food into this ‘only fuel’ will completely reform how you perceive food, health, and exercise science.
I present to you dried milk fueling a train as the first of several food combustion experiments from the past that allow me to explain the physical rules of nutrition and exercise science.
Physical experiments like burning milk briquettes may be used to teach many useful concepts, such as how metabolism of food is really a ‘controlled process of molecular death’. Now, the reason this is useful is because the ‘molecular breakdown of food into fuel’ approach provides a grand unification theory – which means it provides the most simple way to learn how food, metabolism, exercise, and healing all relate to one another.
Before going any further, the most important thing to know is what I mean by ‘controlled process of molecular death’.
As long as you eat food to live – and right now within your body – complex food molecules are breaking down into simpler units – much the same way the complex molecules of your body will breakdown irreversibly after your death. There is a crucial difference of course between life and death. Dead animals do not ‘reverse death’ – but in a sense we do – because our cells ‘control’ the molecular breakdown to a point where we stop it. The point or moment this happens is when the final fuel, acetic acid burns.
So, life within the cell does begin at the ‘edge of death’ in a metaphorical and literal sense – because:
- Life itself is sustained by endless reversal of continuous molecular breakdown – aerobically powered by acetic acid burning within your body.
In other words, metabolism begins when molecular breakdown of food into acetic acid is complete – and at this moment… acetic acid ‘goes up in smoke’. Imagine seeing something materialize onstage before your eyes in a magic act – and at the moment it appears, it vaporizes – it burns. And like burning any fuel such as dried milk, wood, or coal, the basic formula is:
- Fuel + O2 –> CO2 + Heat + Water.
Therefore the entire picture of metabolism can be understood in 2 steps:
- Beginning with eating, the two complex molecules carbohydrates and fat eventually breakdown into acetic acid.
- The fuel burns: Acetic acid + O2 –> CO2 + Heat + Water.
Main Points:
- Fat and carbohydrates breakdown into a small molecule – the fuel that actually burns – acetic acid.
- Aerobic metabolism, prana, and cellular respiration are all the same thing, namely, everlasting combustion of fuel.
Understanding metabolism and nutrition in terms of combusting fuel – whether the fuel is coal, dried milk, glucose, fat, or wood – is the ultimate purpose of this first lesson. Luckily you already know intuitively how a fire works, so I’m not teaching you much besides how a fire within your body scientifically works.
Visualize Acetic Acid
Ignore the similarity between the structures of vinegar and alcohol. For now, you just need to know:
Acetic acid is made from 2 carbon atoms.
Plugging alcohol into the picture of metabolism explains many more connections between food and how the body works. I’ll show you later.
Next, Part 2: Food is the Source of Fuel, not the Transformed ‘Broken Down’ Fuel Your Body Actually Burns.
I’m sorry but I have to disagree with much of this
– the acetate produced in the gut is burned by cells, just as that produced in cells as acetyl-CoA. In fact, acetate from the gut can even reach the liver, enter the TCA cycle as acetyl-CoA, and be used to produce ketones in sufficient quantity to produce so-called “soft drink ketoacidosis”.
– ketones are converted to acetyl-CoA before oxidation in the TCA cycle, they are not an alternate fuel to the acetate process you describe.
– Beta-oxidation of long chain fats is oxidation that produces both acetate and energy, as ATP (via FADH2), and glycolysis is a series of oxidation and reduction reactions that generates ATP (via NADH), and converts glucose to acetyl-CoA or oxaloacetate, which is the catalyst needed to oxidise acetate. So these fuels do “burn” before and after their acetate is oxidised.
It might interest you to know that the cells on the outside layer of skin can take oxygen from the surrounding air and thus do not require a blood supply of oxygen for most of their lifetime.
Was waiting for somebody like you to give an example of what I call going too deep into the rabbit hole right at the beginning for incipient students – as I explicitly said: “As a result of language itself, modern educators and students learn in ways so deep within the rabbit hole that both no longer relate to or understand much about the essential nature of food, health, and human performance.” – I wrote this in Part 5: The Origins of Understanding Food, Fuel, and Metabolism.
Apparently you missed the introductory concept, specifically the third sentence where I wrote: “After you eat and food moves past your stomach, the gut flora living in your intestines transform specific types of carbohydrates into acetic acid; most of this is immediately burned. Then much later, deeper at the cell level of your body, acetic acid fuels metabolism.”
The reader can see the irony; you repeated what I said, “the acetate produced in the gut is burned by cells, just as that produced in cells as acetyl-CoA” – while disagreeing with me!
You served to demonstrate my thoughts exactly from this point forward. Here’s the complete breakdown:
The attempt to clarify details within the big picture should never be the starting point; smart science teaching presents first the general picture, then boils things down to the specific. I purposely avoided the specifics you sought to clarify, i.e. acetic acid is modified and becomes fuel for cells by attaching an enzyme to it, which makes it acetyl-CoA; the acetate produced in the gut is burned by enterocytes and coloncytes; some acetate from the gut reaches the liver; and at the cell level, acetyl-CoA enters the TCA cycle where a series of redox reactions produce energy, etc.
Moreover, I am aware of the linear trip and details of what happens in the gut, liver, and lacteals, e.g. enterocyctes and colon cells feed on acetate and butyrate; these short chained fatty acids do not absorb through the lacteals but instead go through the mesentary system, through the portal vein and to the liver. Any short chained remaining in the blood after this point are carried by albumin in blood, as opposed to how chylomicrons and lipoproteins store and carry long chained fatty acids.
Taking people on a linear trip through the mesentary sytem, to the heart, then outward through the entire cardiovascular system down to the cell level is way overkill for illustrating the immediate big picture!
Instead, I set the stage for students to first see how fatty acids are constructed out of acetic acid – which indisputably simplifies beta-oxidation. Telling people vinegar – a 2-carbon chunk molecule called acetic acid – is the basic building block of fatty acids not only simplifies the process, i.e. 2+2+2… – but it preserves a contextual relationship with food, which is utterly destroyed the moment you introduce the TCA cycle, oxaloacetic acid and the subsequent redox reactions within the cycle.
Also in the beginning, when explaining fermentation and production of acetate (acetic acid), lactic acid and lactate, I want people to understand how a 6-carbon chained fuel, e.g. cellulose, glucose – may ferment into two simple forms: a single acetic acid and a single butyrate. (I show a cow rumen to see fermtenation of cellulose) Therefore people learn how gut bacteria in a cow’s rumen, our colon, and the cytosol of cells basically employ ‘sugar fermentation’. It’s extremely beneficial for people to see fermentation occurs in the gut AND in cells – producing lactate in cells and lactic acid in the gut. Making this connection serves to create a coherent picture. This method also gets people to see immediately simple examples of making carbon fuel substrates and sets the stage for comprehending carbon balance. Since the ‘first splitting’ of carbon fuel starts in the gut – it sets the stage for seeing fermentation/glycoysis within a cell’s cytosol easier as a simple ‘bacterial-like’ less mysterious process.
You say, “acetate from the gut can even reach the liver, enter the TCA cycle as acetyl-CoA, and be used to produce ketones in sufficient quantity to produce so-called “soft drink ketoacidosis”. This is wrong – the majority of ketones are produced via beta-oxidation along the length of the saturated part of a fatty acid – ending at the double bond leaving undesirable fragments. Acetate or acetic acid is not sufficiently abundant to produce ketones; this is why people lose fat under ketosis; a RICH carbon source is needed! This rich carbon source is your store of endogenous fatty acids/triglycerides in adipose tissue. Cellular demand for acetate is as I describe, practically instantaneous. This is why – you know and say – much of the acetic and butyric acid doesn’t leave the gut, it is as you and I say burned.
Anyway, there’s no way acetate is flooding the system under ketosis; endogenous fatty acids ‘flood’ the system…
… and under conditions of insufficient exogenous carbs/glucose – cells produce ketones supplied form endogenous fatty acids. These ketones are sent to the liver to be reconstructed into glucose. Therefore under this condition they will NOT enter the TCA cycle as you describe. Not calling ketones an alternative fuel fails to make clear, the distinctive conditions under which cells adapt and how in the most simple sense the cells TCA cycle conceptually ‘reverse engine’ under low supply of exogenous glucose.
Ketones are 3-carbon chunks long – hence 3 + 3 = 6 = glucose when the liver combines them together. The brain and organs need glucose still, so the body/liver makes it. Hence, my method conveys carbon balance – and there’s no need to go into the rabbit hole – TCA cycle – at this point. Moreover, ketones indeed are an alternative short chained carbon fuel substrate; if you have a beef with calling it an alternative source – that’s simply a matter of semantics – but the primary lesson for is to understand differentiation among carbon fuel substrates. Teaching things your way make it harder for people to get the connections I am conveying.
Moreover, I never conveyed what you say: “they are not an alternate fuel to the acetate process you describe.” My expressed purpose was to avoid the whole ‘acetate process’ i.e. the TCA cycle. The only thing I want beginners to see is “fuel + O2 makes CO2 + water + heat” – and this fuel is primarily acetic acid, and then more specifically: 2-carbon atoms which combine with oxygen, exhaled as CO2. I show how milk, coal, and food burns as fuel and purposely avoid all the details for reasons that I expressed precisely. You exemplify the modern mind and problem with most text books today; teaching details before general picture. I devoted an entire section on this; introducing W.O. Atwater and Lavoisier!
You say: “glycolysis is a series of oxidation and reduction reactions that generates ATP (via NADH), and converts glucose to acetyl-CoA or oxaloacetate, which is the catalyst needed to oxidise acetate. So these fuels do “burn” before and after their acetate is oxidised.” You made a grave teaching error when trying to teach people respiration is a slow form of combustion – which is essentially aerobic metabolism. You destroy it with every detail you mention.
The TCA cycle is indeed a series of electron transfer/redox reactions and H+ production inside a gradient – kicking out protons across the gradient. However oxygen is not COMBINING with all the acids in the TCA cycle – it serves an ‘electron stealer’ – but in the finality at a person’s first gleaning of the process, an incipient’s understanding of the basic chemistry needs to be SIMPLE, i.e. carbon combines with oxygen to produce CO2. People do not need to (and in my view should not) know acetic acid is acetyl-CoA and then is oxidized in the manner you and so many others like to describe to beginners.
I am teaching what aerobic metabolism is (essentially FIRE… made via carbon atoms combining with O2) AND also showing how us humans, i.e. Antoine Lavoiser and W.O. Atwater FIRST understood it and taught it through the spoken and written word, e.g. ‘metabolsim is a slow form of combustion’ and ‘sugar fermentation’ is glycolysis. (Fermentation is anaerobic glycolysis and not aerobic glycolysis… exemplifying why fermentation is the superior word choice over glycolysis) Showing people fermentation occurs in the cytosol or what I call the ‘bacterial’ section of the cell creates a simple bridge. This way people see cells ferment glucose and bacteria in the gut ferment sugar/carbon sources in a likewise fashion where no oxygen is involved.
It does interest me that “cells on the outside layer of skin can take oxygen from the surrounding air and thus do not require a blood supply of oxygen for most of their lifetime.” I’ve come across that but never looked into the details on it. It makes me wonder how cathelicidins or other changing conditions of the skin over time/age affects skin physiology.
I found this both interesting and informative. Looking forward to learning more. Thanks for sharing.
“Each human begins life as a combination of two cells, a female ovum and a much smaller male sperm. This tiny unit, no bigger than a period on this page, contains all the information needed to enable it to grow into the complex …structure of the human body. The mother has only to provide nutrition and protection.”
I think you do not understand the title is an allegory for simplifying fuel substrate utilization! The expressed purpose is to conceive acetyl-CoA, i.e. acetic acid – results from a ‘controlled’ breakdown process akin to how the death process breaks down larger molecules into smaller fundamental ones – e.g. many acids including vinegar. Hence, acetic acid (acetyl-CoA) is fundamentally the ‘final’ carbon fuel for cellular respiration. From this point a continuous reversal of entropy occurs – allowing life and respiration to continue.