Glucose energy content

Carbohydrate accounts for about 40% of the energy content of a normal meal. In the UK, the daily intake is typically 60 g starch, 120 g sucrose, 30 g lactose, 10 g of glucose... 

Only a small fraction of the total free energy content of glucose is released under anaerobic conditions. This is because no net oxidation of organic substrates can occur in the absence of oxygen. Catabolism under anaerobic conditions means that every oxidative event in which electrons are removed from an organic compound must be accompanied... 

Cellulose is synthesized from UDP-D-glucose the energy content of which is used for the formation of glucosidic bonds in the growing polymer ... 

Tl ie energy content of food carboliydrate and food protein is J7 kj/g, whereas that of food fat is 38 kj/g. The energy content of ethanol is 3 kJ/g. Though fairly accurate, these values are only generalizations. For example, consider the energies of different carbohydrates 17,2 kJ/g of starch, 16.6 kJ/g of sucrose, 15,9 kJ/g of glucose. 

Energy can neither be created nor destroyed. When glucose, for example, is oxidized by combustion to CO2 and H2O, its potential energy is lost as heat. However, cells transform the energy content of this reduced organic compound into a useful form by degrading it in small steps, many of which involve oxidation, to its final form, CO2 and H2O. Each small step is accomplished by enzymatic catalysis, and the steps are linked together as sequences of consecutive reactions. If two reactions take place in the same test tube as... 

The energy content of foodstuffs varies. The approximate caloric content of generic carbohydrates, fats, and proteins are listed in Table 23-1. These values are based on a varied diet, i.e., all components are present. Recall that humans cannot synthesize glucose from fat. In the absence of carbohydrates, therefore, fat metabolism becomes inefficient, and the caloric value of fat decreases. 

To understand how the body s heating and cooling mechanisms operate, we can view the body as a thermodynamic system. The body increases its internal energy content by ingesting foods from the surroundings. The foods, such as glucose (C6Hi20g), are metabolized—a process that is essentially controlled oxidation to CO2 and H2O ... 

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