Molecules, Chemistry in Three Dimensions – Peter Atkins
Everything we breathe in, eat, drink, smell and even touch is composed of molecules. Still, because we cannot see the molecules, we have only a vague idea of them. Peter Atkins’ book entitled ‘Molecules, Chemistry in three dimensions’ makes the world of molecules understandable and accessible.
This book aptly illustrates the slogan ‘chemistry is everywhere’. Hef is a description of 160 well-chosen (chemical) substances. By doing this in a refined way, the author manages to create a unique work. Beautiful illustrations stimulate curiosity to such an extent that the accompanying text will be consulted … A concise, thorough introduction and a carefully composed list of terms make it possible for non-chemists to acquire or acquire sufficient knowledge to to form a picture of how nature and chemists use molecules.
Content of Molecules. Chemistry in three dimensions
- Air, water and ammonia
- Smog, air pollution and acid rain
- Soaps, fats and fuels
- Rubber, polyester, acrylic and nylon
- Her. wool and silk
- Sugar, starch and cellulose
- Sweet. sour, bitter, hot, spicy and cool
- Fried foods and animal smells
- Flowers, fruits, essential oils and wine
- Stimulants and sedatives
- Painkillers, bad connections, sex
Example Menthol from Mint
Menthol, the word derived from mint oil, has a characteristic cool taste. It is extracted from the Japanese peppermint (Mentha arvensis) by harvesting the plants as they bloom and drying them, like hay. The oil is then released by steam distillation. Menthol is also made synthetically from turpentine (125). It is also in the common peppermint plant (Menthapiperita) found here and is used in cigarettes, soaps, candies, gum, toothpastes and perfumes for its pleasant scent that accompanies its cool taste. That cool taste is created by the stimulation of cold-sensitive nerve endings in the skin. Menthol makes those sensors active at a higher temperature than normal. The mouth then appears cool, while it is warm.
Example Zingeron from Ginger
Zingeron is the pungent ingredient of ginger, the rhizome of the Zingiber officinale plant. By the way, ginger contains many related molecules, in which one of the hydrogen atoms of the terminal? CH3 group, has been replaced by a longer chain. Different ginger varieties contain different amounts of these compounds. When green ginger root is dried and ground, it not only loses a lot of water through drying out; even water disappears through a reaction between – OH groups and hydrogen atoms from neighboring atoms in the side chain. This creates a double bond between the two carbon atoms and thus a side chain with a different shape. This causes a slight difference in taste, because the composition of the zinger-like mixture has now changed.
Although the relationship between the structure of a stimulating molecule and the development of a pain stimulus is not known, the shape and binding possibilities of the molecule are undoubtedly important. An excitatory molecule fits on a protein in a nerve end: the key fits in the lock, the protein changes shape slightly and the signal travels along the nerve fiber. That it works something like this, we see confirmed when we compare the shape of the capsaicin molecule with that of zingerone. Zingeron lacks a hydrocarbon tail and a nitrogen atom, but is otherwise very similar to capsaicin.
Questions that are chemically answered.
What happens to flamingos when they stop eating shrimp? What went wrong with softenon? How is it possible that the coloring of poppies and cornflowers is the same compound? These kinds of intriguing questions are answered responsibly and interestingly in Molecules.
Molecules. Chemistry in three dimensions. PW Atkins. Scientific Library part 19. Nature and Technology.