In my textbook this week, I read the sentence, “Stereochemistry may seem esoteric, but chirality pervades our very existence” (Smith 182). I thought this sentence was funny because my family has repeatedly joked about how difficult the word esoteric is to remember, which makes sense considering its definition. However, my textbook was also introducing me to a very neat, if very challenging, concept-chirality.
Chirality is a quality possessed when 2 things are not superimposable (in other words, when they cannot be laid on top of each other with everything lining up)(Smith 180). A molecule is always chiral if it has a one carbon that is bonded to 4 unique groups, such as a methyl group, bromine, chlorine, and fluorine (181).
Some items with chirality include:
- Honeysuckles, which wind in a chiral left-handed helix (Smith 182)
- Helical seashells (Smith 182)
- Hands, feet, and ears (Smith 182)
- Quartz stones(Winkelmann par. 5)
- Ibuprofen (NSAID)(Smith 206)
- Fluoxetine (antidepressant)(Smith 206)
- Albuterol (used to treat asthma)(Page par.37)
- Scissors
- The molecule responsible for spearmint scent (Smith 208)
Chiral molecules come in pairs of mirror images. For example, one form of ibuprofen works great, but its mirror image does nothing (Smith 206). Similarly, the compound limonene has one version that smells like oranges, and a mirror image that smells like lemons (Kannappan par. 4)! Each molecular group must be in its particular spot in order to fulfill its function. The purpose of precision in chemistry is evident in the concept of chirality. Therefore, not only the chemical ingredients, but also their mirror image “twins” play a fundamental role in our experience of the compound!
Works Cited:
Kannappan, Valliappan. “The Chemistry of Taste and Smell: How Chirality Affects Senses.” Chiralpedia, 30 July 2024, chiralpedia.com/blog/the-chemistry-of-taste-and-smell-how-chirality-affects-senses.
Smith, Janice Gorzynski. Organic Chemistry With Biological Topics. McGraw-Hill Education, 2021.
Page, Clive P., and John Morley. “Contrasting Properties of Albuterol Stereoisomers .” Journal of Allergy and Clinical Immunology, Aug. 1999, www.jacionline.org/article/S0091-6749(99)70271-X/fulltext.
Winkelmann, Aimo, and Gert Nolze. “Chirality Determination of Quartz Crystals Using Electron Backscatter Diffraction.” ScienceDirect, Feb. 2015, www.sciencedirect.com/science/article/abs/pii/S0304399114002204.
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