By Daniel Rocha LMT CPT
Metabolism refers to the chemical reactions by which living cells grow and sustain life. The chemical reactions are composed of two major types of pathways: anabolism and catabolism. Anabolism uses adenosine triphosphate (ATP) to build larger molecules from smaller molecules. Catabolic reactions degrade larger molecules to produce ATP and raw materials for anabolic reactions.
”Aerobic cellular respiration is made up of three parts: glycolysis, the citric acid (Krebs) cycle, and oxidative phosphorylation. In glycolysis, glucose metabolizes into two molecules of pyruvate, with an output of ATP and nicotinamide adenine dinucleotide (NADH). Each pyruvate oxidizes into acetyl CoA and an additional molecule of NADH and carbon dioxide (CO2). The acetyl CoA is then used in the citric acid cycle, which is a chain of chemical reactions that produce CO2, NADH, flavin adenine dinucleotide (FADH2), and ATP. In the final step, the three NADH and one FADH2 amassed from the previous steps are used in oxidative phosphorylation, to make water and ATP.” (Ahmad, M. 2020)
The above explains how the body has many options for developing energy for the body. Glycolysis will break down glucose into ATP. The krebs cycle uses molecules from glycolysis to also make ATP. Water is also a by product of the reaction.
Oxidative phosphorylation has two parts: the electron transport chain (ETC) and chemiosmosis. The ETC is a collection of proteins bound to the inner mitochondrial membrane and organic molecules, which electrons pass through in a series of redox reactions, and release energy. The energy released forms a proton gradient, which is used in chemiosmosis to make a large amount of ATP by the protein ATP-synthase. (Ahmad 2020)
The above can be explained when following a high-carbohydrate, low-protein diet, the liver enzymes that degrade amino acids are present in low amounts. When following a high-protein diet, with lower carbohydrates, the liver produces increased amounts of enzymes needed to break down more protein.
Anabolic and catabolic pathways are the reactions of reduction and oxidation. Oxidation is the combination of an atom or molecule with oxygen or the loss from it of hydrogen or of one or more electrons. The opposite of oxidation is the gain of one or more electrons by an atom or molecule called reduction. These reactions require them to happen concurrently.
Redox is the coupling of reduction and oxidation. Redox reactions form the basis of metabolism with the transfer of electrons in oxidative phosphorylation transpiring along the electron transport chain. This process is called aerobic respiration, energy is released to make ATP from ADP. The electron carriers are the coenzymes nicotinamide adenine dinucleotide or flavin adenine dinucleotide.
Carbohydrate metabolism begins with glycolysis, which releases energy from glucose or glycogen to form two molecules of pyruvate, which enter the Krebs cycle, an oxygen-requiring process. The pyruvate loses a carbon dioxide group to form acetyl coenzyme A (acetyl-CoA), which requires the B vitamins. The hydrogen in carbohydrate is carried to the electron transport chain, where ATP is conserved. One molecule of glucose yields thirty-one molecules of ATP. Hydrolysis releases ATP through hydrolysis for biological work. (Patel, G. 2019).
Glycogenesis converts glucose to glycogen, stored carbohydrates in your muscles. Glycogenolysis converts glycogen to glucose in the liver to lactate. This is that burning sensation you get from doing high repetition leg extensions. Gluconeogenesis converts amino acids to glucose when carbohydrate intake is limited. So your bodybuilders on high protein, zero carb diets. The liver is responsible for gluconeogenesis. Disorders of carbohydrate metabolism include diabetes mellitus, lactose intolerance, and galactosemia.
Digestion breaks protein down to amino acids. Excess amino acids due to low energy sources of carbohydrates or fats, are metabolized to glycogen, fat or used for energy if needed. If amino acids are used for energy their carbon skeletons are converted to acetyl CoA, so the Krebs cycle can oxidize, producing ATP. The final products of protein catabolism include carbon dioxide, water, ATP, urea, and ammonia. The use of glutamine was used during my bodybuilding days to help rid my body of ammonia. Vitamin B 6 is involved in the catabolism of amino acids, as a cofactor that transfers nitrogen from one keto acid to another. (Patel, G. 2019).
Fatty acids come from macronutrient fats, carbohydrates, and proteins. After digestion of these macronutrient, the fatty acids are carried in the blood as chylomicrons. Lipid metabolism occurs as lipolysis, betaoxidation, ketosis, and lipogenesis.
Lipolysis and beta-oxidation occurs in the mitochondria. It is a cyclical process where two carbons are removed from the fatty acid per cycle in the form of acetyl CoA, where the Krebs cycle produces ATP, carbon dioxide, and water.
Ketosis occurs when large amounts of fat are eaten in the absence of carbohydrates. Note that protein must remain low, otherwise energy will be produced from amino acid not fatty acids. A high fat, zero carbs, low protein diet produces ketones by the liver.
Lipogenesis occurs in the cytosol, with triglyceride synthesis stemming from the liver, adipose tissue, and intestinal mucosa. The fatty acids are derived from the hydrolysis of fats, the synthesis of acetyl CoA through the oxidation of fats, glucose, and some amino acids. (Patel, G. 2019). Meaning that fatty acids are derived from adding water and oxygen to the digestion process.
Theory of Omegas
Omega-3 fatty acids are a group of fatty acids that get their name from the double bond attached to the number 3 carbon atom, counting from the omega end of the molecule. (Odle 2020). The omega-3 fatty acid alpha-linolenic acid is an essential fatty acid because it is essential for life, health, normal growth, and development. The omega-3 essential fatty acid must be supplied one's diet as the body is unable to make it.
Studies have shown that diets rich in omega-3 fatty acids decrease risk of heart attacks, strokes, and abnormal heart rhythms. Omega-3 fatty acids thin blood, raise HDL, lower LDL, and reduce plaque build up in the arteries. Clinical trials show that regular consumption of fish or fish-oil supplements prevents sudden death due to abnormal heart rhythms. (Odle 2020)
Digestion of food begins in the mouth, moves on to the stomach, and then into the small intestine, where specific enzymes process different types of sugars. The enzymes lactase, maltase, and isomaltase break down the disaccharides. Carbohydrate intolerance occurs when one or more enzymes are produced in inadequate amounts. The deficiency of the enzyme lactase is the most common of all enzyme deficiencies.
Carbohydrate intolerance can be primary or secondary. Primary deficiency is caused by a birth defect or developed over time. Secondary deficiencies are caused by a disease or disorder of the intestinal tract. Diseases such as protein deficiency, celiac disease, and some intestinal infections, will disappear once treated. Treatment for primary conditions can be controlled by diet, such as consuming chewable lactase enzyme tablets before a meal or choosing lactose-reduced milk and other dairy products. (Kaczkowski 2018)
Many are unfamiliar with how macronutrients work to heal and provide the body with energy. Energy is not limited to being able to run a mile, but to allow the body to undergo all of its chemical reactions that allow cells to heal, recover and replicate. Manual therapy can be more vigorous than exercise, so the body will not only require rest, but the correct nutrients, vitamins and minerals needed to repair connective tissue. Clear vitaways (blood, lymph, and nerve impulses) allow for a speedy recovery with increased improvement in the quality of life.
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Ahmad, M. (2020, April 29). Biochemistry, Electron Transport Chain. Retrieved July 29, 2020, from https://www.ncbi.nlm.nih.gov/books/NBK526105/
Ericson, K., RN, & Caffrey, C. (2016). Carbohydrate Intolerance. In D. S. Blanchfield (Ed.), The Gale Encyclopedia of Children's Health: Infancy through Adolescence (3rd ed., Vol. 1, pp. 486-488). Farmington Hills, MI: Gale. Retrieved from https://link.gale.com/apps/doc/CX3630900149/HWRC?u=lirn33148&sid=HWRC&xid=e3d28925
Kaczkowski, C. H., MSc. (2018). Metabolism. In J. L. Longe (Ed.), The Gale Encyclopedia of Nursing and Allied Health (4th ed., Vol. 4, pp. 2290-2295). Farmington Hills, MI: Gale. Retrieved from https://link.gale.com/apps/doc/CX3662600730/HWRC?u=lirn33148&sid=HWRC&xid=8c304f77
Odle, T. G., & Blake, S., ScD. (2020). Omega-3 Fatty Acids. In D. S. Hiam (Ed.), The Gale Encyclopedia of Alternative Medicine (5th ed., Vol. 4, pp. 1948-1953). Farmington Hills, MI: Gale. Retrieved from https://link.gale.com/apps/doc/CX7947800642/HWRC?u=lirn33148&sid=HWRC&xid=869f685e
Patel, G. (2019). Metabolism. In D. S. Hiam (Ed.), The Gale Encyclopedia of Diets (3rd ed., Vol. 2, pp. 916-918). Farmington Hills, MI: Gale. Retrieved from https://link.gale.com/apps/doc/CX2491000226/HWRC?u=lirn33148&sid=HWRC&xid=65a16205M