Our NanoTechnology in Health and Skincare
Cellular Respiration
Taken from https://www.biology.iupui.edu
How to provide energy for the work of 75 trillion cells?
All our health supplements and aesthetic products promote the function of cell respiration or Krebs cycle. During Cellular Respiration, sugar is broken down to CO2 and H2O, and in the process, ATP is made that can then be used for cellular work.
C6H12O6 + 6O2 ---------------> 6CO2 + 6H2O + ~38 ATP
ALL cells must able to break down sugars they take in from their environment and turn it into energy to be used in cellular work.
Essentially, sugar (C6H12O6) is burned, or oxidized, to CO2 and H2O, releasing energy (ATP) in the process.
Why do cells need ATP? ALL cellular work -all the activities of life - requires energy, either from ATP or from related molecules. A lot of oxygen is required for this process! The sugar AND the oxygen are delivered to your cells via your bloodstream.
This process occurs partially in the cytoplasm, and partially in the mitochondria. The mitochondria is another organelle in eukaryotic cells. like the chloroplast; the mitochondria has two lipid bilayers around it, and its own genome. In some ways similar to the chloroplast, the mitochondria also has two main sites for the reactions: The matrix, a liquidy part of the mitochondrion, and the christae, the folded membranes in the mitochondrion.
Taken from https://www.biology.iupui.edu
Cellular Respiration can be broken down into 4 stages
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Glycolysis ("splitting of sugar"): This step happens in the cytoplasm. One Glucose (C6H12O6) is broken down to 2 molecules of pyruvic acid, resulting in the production of 2 ATPs for every glucose.
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Transition Reaction: Pyruvic Acid is shuttled into the mitochondria, where it is converted to a molecule called Acetyl CoA for further breakdown.
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The Krebs Cycle, or Citric Acid Cycle: Occurs in the mitochondrial matrix, the liquid part of the mitochondria. In the presence of Oxygen gas (O2), all the hydrogen's (H2) are stripped off the Acetyl CoA, two by two, to extract the electrons for making ATP, until there are no hydrogen's left - and all that is left of the sugar is CO2 - a waste product - and H2O (which are exhaled). The Krebs cycle results in the production of only ~4 ATPs, but produces a lot of NADH, which will go on to the next step. (Hans Krebs won the Nobel Prize in 1953 for his discovery of the Citric Acid Cycle.)
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The Electron Transport Chain and Chemiosmosis ("the big ATP payoff") occurs in the christae of the mirochondria, the folded membranes inside the chloroplast. Electrons from Hydrogen are carried by NADH and passed down an electron transport chain to result in the production of ~32 ATPs for every glucose. (Peter Mitchell won the Nobel Prize in 1978 for his work on energy production in mitochondria, called the Chemiosmotic Theory.)
So - all of these steps to do...what? - BREAK DOWN GLUCOSE TO MAKE ATP ~38 ATPs for every glucose!!!
What's so great about ATP? - Every time you move a muscle, think, breathe, replicate your DNA, every time your heart beats - you use ATP to do this work!
Alternative Energy in the Body
What if the body runs out of sugar for glycolysis? Can the body still make ATP?
Yes, this is what the Lo-carb diets are based on...draining the carbohydrate levels and reserves of your body, so that to make daily energy (ATP), you body has to turn to an alternate source of fuel...fats and proteins!
Fats as fuel: Triacylglycerol reserves (located in unpleasantly strategic locations on your body ...) tend to be stored in adipose cells. Lipases are released into the bloodstream and break down fats in the bloodstream (from the fats and oils we eat) or travel to adipose cells.
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Lipases break the glycerol head away from the fatty acids.
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Glycerol is converted to an intermediate in glycolysis called "PGAL", and enters cellular respiration in the cytoplasm.
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The fatty acid tails are converted to Acetyl CoA and enter the Krebs cycle in the mitochondria
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Result: Still ~32-38 or so ATPs, but from fats, not glucose!
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Proteins as fuel: Excess proteins in our diets cannot be stored like glycogen or fats can, and must be broken down by the body.
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Proteases break the peptide bonds of proteins back down to amino acids
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Deaminases break the amino group off the amino acids, releasing ammonia. This toxic ammonia is converted to urea, and is excreted in urine.
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The remainder of the amino acid (mostly of carbon, hydrogen, and oxygen), can be rearranged in cells to enter cellular respiration either as pyruvate, as acetyl CoA, or directly into the Krebs cycle.
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Result: Still ~32-38 or so ATPs, but from proteins, not glucose!
Anaerobic Respiration (Fermentation)
If enough oxygen is present in cells, each glucose molecule will produce ~38 ATPs - lots of energy, for lots of cellular work. However, what happens if you (or another organism) run short of oxygen? (Like if you are a sprinter, or being chased by a LION, or in an aerobics class but WAY above your target heart rate?) How does your body get energy to do its cellular work when oxygen is limited?
In suboptimal O2 concentrations, a partial breakdown of sugar occurs that results in just a bit of energy, enough to keep a cell alive or working for a while, but not as efficiently. This process is called fermentation, or anaerobic respiration. Usually the process goes only as far as glycolysis (2 ATPs), and does not enter the mitochondria for further breakdown. However, these 2 ATPs give your body enough energy to cross the finish line...and hopefully avoid being eaten by that lion…
In our cells, anaerobic respiration results in the production of lactic acid, the molecule that builds up when you 'feel the burn' during or after strenuous exercise. The lactic acid, plus the hydrogens (2H) released, cause the muscle to become more acidic, causing pain and burning in the muscle.
Final Take Away
We tend to associate the term respiration with breathing and the lungs, but here we talked about cellular respiration. What's the connection?
The function of the lungs is to pull in the oxygen our mitochondria need to burn sugar and remove the CO2 our mitochondria generate after breaking that sugar down!! We can't burn sugar well without oxygen, and we can't get oxygen to all our cells without our lungs, our blood cells (which carry oxygen) and our heart!
A healthy body requires cell respiration to function properly to produce ATPs for cells to work. We strive to assist the proper production of ATPs!