Glycolysis, anaerobic

the two routes can be compared. In the one, in the limit, lactic acid or lactate formation can be assumed not to proceed during aerobic glycolysis, with carbon dioxide and H2O as the final products. In the other, only lactic acid or lactate will be the final product during anaerobic glycolysis. 

This is the normal body process whereby glucose or blood sugar is converted ultimately to carbon dioxide and water. Following the ten-step conversion of glucose to pyruvic acid, the pyruvic acid is then converted to the end products of carbon dioxide and water via what is variously called the tricarboxylic acid, or citric acid, or Krebs cycle. The conversion is strongly exothermic, fueling the body s internal processes and its external activities. 

Consider the phenomenon referred to as spontaneous human combustion (SHC), as publicized from time to time (e.g., as was reported in Arthur C. Clarke s Mysterious Universe, shown on the Discovery Channel, for instance, on October 22,1996, and was mentioned in Charles Dickens Bleak House). If this weird phenomenon does indeed occur, it could instead be referred to as spontaneous ignition, followed by combustion. And if it is at least conceivable for aberrations to occur among the enzyme-catalyzed reactions involved in the metabolism of glucose or other carbohydrates to yield CO2 and H2O, then conceivably there may be a case. Ordinarily, body metabolism reaction rates are miniscule as compared to the direct combustion or combustive oxidation of conventional fuels. If enzyme promoters exist, however, there is the possibility that runaway metabolic processes occur, similar to those in the ignition and further combustion of carbonaceous materials. If so, ample air or oxygen supply would also be required for this extremely unlikely scenario. 

As for the human body system, a fever can be induced by reducing the heat normally dissipated to the surroundings. The phenomenon can be viewed in terms of the caloric intake, without heat dissipation. If this heat is not dissipated, the body temperature would continue to rise inordinately. 

Adding all the chemical equations involved, the overall net conversion of glucose to lactic acid is slightly exothermic, which indicates that not much metabolic energy results. In consequence, the anaerobic glycolysis rate must increase manyfold to 

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A Sprinter Uses Creatine Phosphate Anaerobic Glycolysis to Make ATP, Whereas a Marathon Runner Uses Oxidative Phosphorylation... 

Glucose derived from muscle glycogen and metabolized by anaerobic glycolysis is the major fuel source. Blood glucose and free fatty acids are the major fuel sources. 

Skeletal muscle functions under both aerobic (resting) and anaerobic (eg, sprinting) conditions, so both aerobic and anaerobic glycolysis operate, depending on conditions. 

Gluconeogenesis Formation of glucose from precursors other than carbohydrates (especially by the liver and kidney) using amino acids from proteins, glycerol from fats, or lactate produced by muscle during anaerobic glycolysis. 

Continuous cerebral circulation is required to sustain brain function. Not only does the brain utilize 02 at a very rapid rate, but the brain is absolutely dependent on uninterrupted oxidative metabolism for maintenance of its functional and structural integrity. Even at its maximal rate, anaerobic glycolysis can provide only a small portion of the required energy. Since the amount of 02 stored in brain is extremely small compared with its rate of utilization, the brain requires a continuous supply of 02 from the circulation, and brief disruptions in this supply have an immediate effect on brain function and consciousness. 

Gleitz J, Tosch C, Beile A, Peters T (1996b). The protective action of tetrodotoxin and (+/-)-kavain on anaerobic glycolysis, ATP content, and intracellular Na-i- and Ca2+ of anoxic brain vesicles. Neuropharmacology. 35(12) 1743-52. 

In ischemic episodes such as occur in myocardial infarction, lack of oxygen forces cells to rely on anaerobic glycolysis, which increases production of lactic add The consequent intracellular acidosis can cause proteins to denature and precipitate, leading to coagulation necrosis. 

Fast-twitch muscle fibers have a high capacity for anaerobic glycolysis but are quick to fatigue. They are involved primarily in short-term, high-intensity exercise. Slow-twitch muscle fibers in arm and leg muscles are well vascularized and primarily oxidative. They are used during prolonged, low-to-moderate intensity exercise and resist fatigue. Slow-twitch fibers and the number of their mitochondria increase dramatically in trained endurance athletes. 

Short bursts of high-intensity exercise are supported by anaerobic glycolysis drawing on stored muscle glycogen. 

In red blood cells, anaerobic glycolysis represents the only pathway for ATP production, yielding a net 2 ATP/glucose. 

The red blood cell has no mitochondria and is totally dependent on anaerobic glycolysis for ATP. In pyruvate kinase deficiency, the decrease in ATP causes the erythrocyte to lose its characteristic biconcave shape and signals its destruction in the spleen. In addition, decreased ion pumping by Na /K -ATPase results in loss of ion balance and causes osmotic fragility, leading to swelling and lysis. 

Answer E, A right-shift in the Oj binding curve is indicative of abnormally elevated 2,3-BPG secondary to a defect in red cell anaerobic glycolysis. Only pyruvate kinase participates in this pathway. 

Hypoxia deprives the ETC of sufficient oxygen, decreasing the rate of ETC and ATP production. When ATP levels fell, glycolysis increases and, in the absence of oxygen, wiU produce lactate j (lactic acidosis). Anaerobic glycolysis is not able to meet the demand of most tissues for ATP, I especially in highly aerobic tissues like nerves and cardiac muscle. 

Answen B. Both PFK-1 and LDH participate in extrahepatic anaerobic glycolysis, but only PFK-1 is regulated by allosteric effectors. 

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