Anaerobic oxidation, glucose

Anaerobic Oxidation of ducose. Historically, the first system of carbohydrate metabolism to be studied was the conversion by yeast of glucose to alcohol (fermentation) according to the equation CnH,Of,2CH)CH,OH + 2CO . The biochemical process is complex, involving the successive catalytic actions of 12 enzymes and known as the Emhden-Meyerhof pathway This series of reactions is summarized in the entry on Glycolysis. 

But even if a combination of pathways usually is used, the ATP yield can nevertheless be elevated two- to fourfold any animal anaerobes utilizing such fermentations therefore automatically reduce by a factor of two to four their anaerobic needs for glucose. Although impressive, this factor is still a long way from the order-of-magni-tude difference between anaerobic glycolysis and oxidative glucose metabolism. 

QUESTION 1 2.4 In the absence of oxygen, cells can produce small amounts of ATP from the anaerobic oxidation of glucose. This is not true for fatty acid oxidation. Explain. 

Anaerobic oxidation of glucose by glycolysis to form ATP and lactate... 

Yield of Air from the anaerobic oxidation of glucose to lactate... 

Glycolysis, an anaerobic process, oxidizes glucose to yield a 3-carbon compound, pyruvic acid. Obviously, a large part of the chemical energy stored in the glucose molecule remains unavailable for cellular metabolism. Fortunately, there exists a biochemical device capable of oxidizing pyruvic acid to CO2 and water in the presence of oxygen. It is known as the Krebs cycle, the tricarboxylic acid cycle, or the citric acid cycle [69-73] (see Fig. 1-13). 

Although the glycolytic pathway and the hexose monophosphate shunt constitute the core of the enzyme mosaic of the red cell, other enzymic systems, the roles of which sometimes are less obvious than those involved in the anaerobic oxidation of glucose, have also been found. 

The modes of action for niclosamide are interference with respiration and blockade of glucose uptake. It uncouples oxidative phosphorylation in both mammalian and taenioid mitochondria (22,23), inhibiting the anaerobic incorporation of inorganic phosphate into adenosine triphosphate (ATP). Tapeworms are very sensitive to niclosamide because they depend on the anaerobic metaboHsm of carbohydrates as their major source of energy. Niclosamide has selective toxicity for the parasites as compared with the host because Httle niclosamide is absorbed from the gastrointestinal tract. Adverse effects are uncommon, except for occasional gastrointestinal upset. 

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