Tag Archives: enzymes

Odour Chemicals in Armpit 

Human Armpit cavity provides an ideal environment for growth of bacteria. The intensity of bacteria in the armpits is mind boggling. In fact, it is reported that there are a million bacteria per square centimeter. Not only are their population so high, there are so many different types of them. They produce chemicals by breaking down the precursor chemicals present in sweat which cause the stinking smell. The odours are so embarrassing to people that millions of dollars industry of deodorants thrives due to this.

This means that in addition to ideal temperature and lodging facilities like folds of skin and hair, the armpits secretions must be supplying them with chemicals they depend upon to extract energy for survival.

Armpits contain sweat chemicals. When these chemicals are broken down into other compounds by bacteria many of these end products give of very obnoxious smells. Bacteria produce sulphur containing compounds which give off nauseating onion like smell. Then there are compounds which are degraded into organic acids. One of the acids gives the “cumin like smell” while another acid gives odour similar to the one which comes from the goats.

Then they produce pheromones which are the chemicals that attracts the opposite gender person. Two possible pheromones are Androstenol (alcohol) which smells like “musk” and other is Androstenone. (ketone) which smells differently to different persons.

Two low molecular weight acids namely iso-valeric and we’ll known acetic acid are also produced. The first one gives cheesy, sweaty foot smell and other as is commonly known  as the vinegar smell.

These chemicals are produced by bacteria using different enzyme reaction routes..

The details of the odour chemicals and their precursors, enzyme and bacteria responsible for these are given in this article..

Chemistry by Nature

Nature is a great chemist. It synthesizes millions of compounds every moment ranging from simple molecules like methane to very complex molecules like carbohydrates, cellulose and proteins. Most of these compounds are synthesized by plants. From the plants they are passed on to animals because the animals cannot synthesize their food by themselves. But there are many chemical reactions occurring inside the cells like breaking down the complex molecules and unlocking the energy which is stored in them.

Where does all the energy locked inside the different molecules come from? Most of it is derived from the Sun light. In many cultures like Hindus and Egyptians, Sun is worshiped as the harbinger of life. They may not be knowing the scientific facts behind it. Energy tries to dissipate and some storage is required to held it at one place and use it whenever required. Cells are the prime example.

How do the plants get hold of the energy. They carry out a reaction called photosynthesis in which they combine carbon dioxide and water in the presence of sunlight. All this work is done with the help of a big organic molecule called Chlorophyll. The products of this reaction are sugar and oxygen. When human beings consume the sugar, they break it down again to carbon dioxide and water and energy absorbed from the sun is unlocked and nourishes our bodies.

This reaction is a fuel burning reaction. But unlike the burning of fuels it happens at a very low temperature (body temperature) in our bodies although both reactions are exothermic in nature. How is this achieved? First of all, only those reactions are possible which results in products having lower energy than the reactants. But to initiate the reaction, the system has to cross a energy hill called energy of activation.

Catalysts are capable of making the reactions occur at low temperatures because they lower the energy of activation. In our bodies there are specialized proteins which are called enzymes which act as catalysts. These are very specific and one enzyme is specialized for only one task.

Catalysts also determine the kind of product that is synthesized. For example, the hydrogenation of unsaturated oils can be carried out by reaction with hydrogen. In the case of using a catalyst, only cis addition to the double bond is allowed whereas without catalyst in addition to elevated temperature and pressure conditions, the product formed is a mixture of both cis and trans products.

Since in the nature most of the reactions are carried out at ambient conditions, enzymes are generally utilized by the nature. In the case of molecules having asymmetric carbon centres a mixture of 50:50 ratio is produced without enzymes. These are called stereo-isomers and rotate the light in left and right direction. But in nature only one of these forms is synthesized. After all animals consume only one form of stereoisomers.

So nature is a great chemist.