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Fuel Values of Foods and Other Substances

The food we eat is broken down, or metabolized, in stages by a group of complex biological molecules called enzymes. Most of the energy released at each stage is captured for function and growth. One interesting aspect of metabolism is that the overall change in energy is the same as it is in combustion. For example, the total enthalpy change for the conversion of glucose (C 6 H 12 O 6 ) to carbon dioxide and water is the same whether we burn the substance in air or digest it in our bodies: C 6 H 12 O 6 ( s ) + 6 O 2 ( g ) →   6CO 2 ( g ) + 6 H 2 O ( l )                                                        ΔH = - 2801 kJ/mol The important difference between metabolism and combustion is that the latter is usually a one-step, high-temperature process. Consequently, much of the energy released by combustion is lost to the surroundings. Various foods have different compositions and hence different energy contents. The energy content of food is generally measured in calories. Th
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How a Breathalyzer / Alcoblow works and why it may not be possible to trick or beat it

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The term “alcohol” to a chemist means an organic compound that contains an OH group, but as far as the public is concerned “alcohol” refers to one specific compound, namely, ethanol. It is ethanol that we consume in wine, spirits or beer, and when we measure blood alcohol content (BAC), we’re really measuring blood ethanol content. Alcohol that a person drinks shows up in the breath because it gets absorbed from the mouth, throat, stomach and intestines into the bloodstream. Alcohol is not digested upon absorption, nor chemically changed in the bloodstream. As the blood goes through the lungs, some of the alcohol moves across the membranes of the lung's air sacs (alveoli) into the air, because alcohol will evaporate from a solution -- that is, it is volatile. The concentration of the alcohol in the alveolar air is related to the concentration of the alcohol in the blood. As the alcohol in the alveolar air is exhaled, it can be detected by the breath alcohol testing device. Inst
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What do you know about table sugar? And the common misconception that raw and unrefined sugars are healthier than refined sugar.

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Sugar is made by some plants to store energy that they don't need straight away, rather like animals make fat. People like sugar for its sweetness and its energy so some of these plants are grown commercially to extract the sugar. What we call table sugar, chemist know as 'sucrose', one of the family of sugars otherwise known as saccharides in the grouping called carbohydrates. Carbohydrates, as the name implies, contain carbon and hydrogen plus oxygen in the same ratio as in water. The saccharides is a large family with the general formula CnH2nOn. The simplest of the sugars is glucose, C 6 H 12 O 6 , although its physical chemistry is not that simple because it occurs in two distinct forms which affect some of its properties. Sucrose, C 12 H 22 O 11 , is a disaccharide, a condensation molecule made up of two glucose molecules. The process whereby plants make sugars is photosynthesis. The plant takes in carbon (IV) oxide from the air through pores in its leaves and abs
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Why bother with heterocycles organic compounds?

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  A recent analysis of the organic compounds registered in Chemical Abstracts revealed that as of June 2007, there were 24,282,284 compounds containing cyclic structures, with heterocyclic systems making up many of these compounds – about two third of organic compounds are heterocyclic. Most pharmaceuticals are based on heterocycles. An inspection of the structures of the top-selling brand-name drugs in 2007 reveals that 8 of the top 10 and 71 of the top 100 drugs contain heterocycles. The history of medicine can be defined by heterocyclic compounds.                                                                    Quinine                         As early as 16 th century have been used to treat malaria.                                                                                                                            Antipyrine                                   The first synthetic drug (1887) (used for reduction of fevers)                  
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TO ARRIVE AT THE PERFECT DIET, STOP SWALLOWING EVERYTHING YOU’RE FEED.

 There’s a joke doing the rounds that warns against reading of the many health books. You might just end up dying of a misprint. Cynical as it sounds, a healthy dose of scepticism maybe the one way to get a meaningful perspective. Especially now, when every quack and his mate are setting up websites or writing sensationalist books. The scientific truth is somewhat less dramatic. There are no good or bad foods. Only good or bad diets. Singling out a particular food as the source of all evil is as laughably unscientific as claiming that the moon is made of cheese. How on earth does any study single out all the various factors contributing to our health anyway?  Consider that simple carbohydrate, table sugar as an example. It’s half fructose, half glucose. It has half the calories of fat. And it is almost in the middle of the glycemic index, neither high nor low. Yet it’s often maligned as the cause of anything from gingivitis to depression. The scientific evidence is much more
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