What we’ll talk about
Mitochondria are membrane-bound cell organelles resembling small beans. Found in almost every cell of our body (except red blood cells), where it fulfills its irreplaceable function. Each cell has thousands of them, depending on the type of cell. Mitochondria are our cellular energy factories that provide a constant supply of ATP. Most of the ATP that our body or cells use is recycled, which means they do not need to rely on ATP from external sources.
Mitochondria generate the vital energy of ATP thanks to oxygen and the use of substrate from food. In the Krebs cycle, additional NADH2 and FADH2 molecules are formed from Ac-CoA obtained from beta-oxidation and glycolysis. This is the final and MOST IMPORTANT PHASE for us, which is the electron transport chain. Our mitochondria are our favorite cellular energy factory, the mitochondria.
The Powerhouses of Cells: Mitochondria
Mitochondria: Our Cellular Energy Factories
Have you ever thought about where you get your energy for everything you need to do every single day? Have you ever wondered where your tissues and organs get their energy to function properly? Or if we go even deeper, where do your cells get their energy from, which are about 23 billion in total and have a performance far higher than any existing computer?
If you’ve been educating yourself in the field of biology, biochemistry, etc., you know that it’s not about food and its consumption every 3 hours, but about “our” cellular energy factories, which are called: Mitochondria!
Mitochondria are membrane-bound cell organelles resembling small beans. It is found in almost every cell of our body (except red blood cells), where it fulfills its irreplaceable function, which is the continuous production of energy.
It is important to know that we do not have just one or a few mitochondria in our cells, but each cell has thousands of them, depending on the type of cell. For the sake of interest, it is reported that the the human body has around 100 trillion of these cell factories!
The Vital Role of Mitochondria
You may be wondering why we should even be concerned with something like mitochondria, of which there is such an enormous number…
The answer is that it is the most important part of the puzzle affecting our health, life energy, aging, and indeed our entire life, including its quality. This part of the puzzle is also likely to change the entire paradigm in the field of disease prevention and longevity or even understanding of the reality around us shortly.
Mitochondria and Evolution
Mitochondria and the Tipping Point of Evolution
To understand mitochondria and their importance as best as possible, we must go into the billions of years of the distant past, where crucial moments of the emergence of more complex organisms took place in the ancient oceans.
According to the prevailing paradigm, mitochondria are descendants of bacteria that were once completely independent organisms in ancient times, but during evolution were absorbed by eukaryotic cells that began to use them for energy.
This means that every eukaryotic cell and almost every cell in our body is made up of two different life forms. It is essentially a sacred duality that enabled the rocket development of multicellular organisms, including higher plants, animals, and man.
The assumption that mitochondria evolved from bacteria (specifically from Rickettsiales proteobacteria) is that mitochondria have their DNA (mtDNA), which is very similar to bacterial DNA since it contains only 37 genes and is circular in shape.
The Symbiotic Relationship with Mitochondria
Mitochondria thus became an extremely effective partner of our cells, helping them to oxidize substrates for energy that they could not use before. These are, for example, fatty acids, from which, with the help of beta-oxidation, the Krebs cycle, and the electron transport chain, they produce far more energy (ATP) than was the case with the “old” glycolysis of glucose molecules, which ceased to be energetically sufficient for the next necessary development.
Mitochondria are still a hot topic in science and there are many unanswered questions surrounding them, especially regarding their origin, genome, etc. The interesting thing is that, for example, the genome of the offspring of mitochondria is extremely different from other organisms and no one knows the “bulletproof” answer why.
I believe that thanks to our interest in science, we can look forward to more interesting findings in the future that will allow us to better understand the evolution and deeper meaning of these symbiotic friends of ours in our world.
Mitochondria and ATP
Mitochondria and ATP Production
You probably know from your study that mitochondria are our cellular energy factories that provide a constant supply of energy in the form of adenosine triphosphate (ATP) for all the cellular processes of our organism and their continuous operation.
Mitochondria generate the vital energy of ATP thanks to oxygen and the use of substrate from food and other secondary sources, but most importantly, what is extremely important, is its reverse recycling! Most of the ATP that our body or cells use is recycled, which means that they do not have to rely on the constant production of ATP from the mentioned external sources.
The Energy Production Process
On the contrary, through food, we get glucose and fatty acids into our body and its metabolism, which enter different “systems”, where glucose enters glycolysis in the cell space and fatty acids go straight to the mitochondria, to the beta-oxidation process.
In both cases, a certain amount of ATP is produced, but more importantly, the substrates are formed, which are Acetyl Coenzyme A (Ac-CoA) and a molecule called NADH2. Subsequently, Ac-CoA travels to the next system, which is the Citrate or Krebs cycle.
In the Krebs cycle, which you can imagine as an energy “wringer”, additional NADH2 and FADH2 molecules are formed from Ac-CoA obtained from the process of beta-oxidation and glycolysis, which enter the final and MOST IMPORTANT PHASE for us, which is the electron transport chain (ETC).
The ETC is located on the inner mitochondrial membrane and is a cascade of molecules called complexes through which the universal energy fuel ATP is produced.
The Importance of Efficient Energy Production
From this, albeit very simplified, but for some perhaps exhaustive description of ATP energy production, you may have noticed that it is not obtained directly from nutrients from the diet, but is created from substrates, from which, with the help of the electron transport chain, mitochondria create our life energy, which is subsequently largely further recycled, to maintain its continuous operation.
But what does this mean in practice?
In practice, we want these processes to take place as efficiently as possible, without excessive losses and damage, which in the long run can lead to various problems, which we will further address in other posts.
The Role of Mitochondria in Aging
Aging and Its Relation to Mitochondria
Like it or not, we are all subject to something we can call the entropy of life, which is the tendency of complex systems, including living organisms and humans, to gradually move toward chaos, senescence, and death. Yes, this is aging, which describes the gradual process of entropy of our physical body from birth to death.
But it is extremely important to know that aging can be fundamentally influenced by our lifestyle, where we can speed up this process very effectively on the one hand, but what is most important, also slow it down.
From a biochemical point of view, our aging occurs for various reasons and levels, one of the most important of which is our favorite cellular energy factory, the mitochondria.
Free Radicals and Mitochondrial Damage
As we have already mentioned, they produce our body’s life energy in the form of ATP, when (and now this is important) there is also the production of something we call free radicals, the most famous of which are the so-called reactive oxygen species (ROS).
Free radicals in themselves are not necessarily evil because they are involved in maintaining the redox balance, but the problem arises when our mitochondria produce excessive amounts of them.
Effects of Mitochondrial Dysfunction
What happens is that there is increased damage to the mitochondria and their mtDNA and at the same time damage to our cells and their nuclear DNA. With long-lasting damage without proper restoration, the process deepens and the mitochondria gradually lose their function. This leads to the fact that the mitochondria do not supply the cell with enough energy and they gradually cease to fulfil their function.
At this moment, it is the turn to start the mitochondrial program of cell suicide, which is apoptosis. If this program does not work, then senescence occurs and our body begins to contain a large number of unnecessary and mainly worn-out cells, generating more and more oxidative stress and damaging our health.
All of these events can manifest on a macro level as a lack of vital energy, emerging partial or chronic health problems, poor appearance and quality of the skin, and a whole host of other manifestations of accelerated aging.