Michael Austin

Don Larson 


22 July 2021

Exergonic and Endergonic Via Sound

As a student of music at the University of Alaska Fairbanks I have always been interested in the science behind sound. Whether that be in the form of sound waves which the individual listener hears or the reason that some notes sound good with others and some notes clash(overtone series). Preparing for this project I wanted to take advantage of the skills I have acquired to portray a scientific concept(s) through sound. And through this sound example that I have composed I will be able to demonstrate the reactions produced by both Exergonic and Endothermic reactions. 

For starters, an Exergonic reaction is one that creates a product with less potential energy than there was to begin with. In other words the reaction has a release of energy and has little left over. This implies that there was an instantaneous release of energy or spontaneity. The way that I demonstrated this in the original composition “Exergonic and Endergonic” is by use of a constant note in the cello of a string quartet creating a drone effect or the catalyst for the reaction to combust above in the viola, first, and second violins. Only four notes go by when “spontaneously” a texturly rich melody breaks out for a four bar phrase. This happens very quickly, and what remains is the product, a simple three voice harmony overlying the droning cello pulsing in the background. 

Making an instantaneous transition to the Endothermic portion of the work. An Endothermic reaction is one that results in an absorption of energy during the chemical change. A good way of describing this is obseverbing metabolism, an endergonic process here is anabolic, referring to the stored energy. An example of this anabolic processed energy is supplied by joining the reaction to adenosine triphosphate(ATP) and consequently resulting in a higher energy. 

The way I create this effect in the work is through the first violin. The reactive elements in this context are the notes C and B natural. This reaction takes place in the key of C minor(Beethoven’s Favorite Key) and the B natural is only found in the dominant or the five chord built on the fifth scale degree in the key of C minor. What makes it so volatile is the fact that it is only a semitone away from C. This causes a tension to be built between when played close together. There is a clash! Followed promptly by a wild reaction of tension with the tempo marking of Vivace (Really Fast in Italian). And that is an auditory example of Exergonic and Endergonic Reactions!

IUPAC, Compendium of Chemical Terminology, 2nd ed. (the “Gold Book”) (1997). Online corrected version:  (2006–) “exergonic (exoergic) reaction

Engedahl, Unni, et al. “Reaction Mechanism for Methane-to-Methanol in Cu-SSZ-13: First-Principles Study of the Z 2 [Cu 2 O] and Z 2 [Cu 2 OH] Motifs.” Catalysts (2073-4344), vol. 11, no. 1, Jan. 2021, p. 17. EBSCOhost, doi:10.3390/catal11010017.

Chongqin Zhu, et al. “Formation of HONO from the NH3-Promoted Hydrolysis of NO2 Dimers in the Atmosphere.” Proceedings of the National Academy of Sciences of the United States of America, vol. 115, no. 28, July 2018, pp. 7236–7241. EBSCOhost, search.ebscohost.com/login.aspx?direct=true&db=edb&AN=130668869&site=eds-live.

One Comment

  1. According to our A&P textbook, all chemical reactions are either exergonic (catabolic, breaking down, and giving off energy) or endergonic (anabolic, assembling, and using up energy). I love your creative idea of using music to express these energy dynamics. I wish that you had also recorded the sound effect of your composition, which would be much easier for me to grasp the audio effect of your analogies.
    I would like to share a bit more on exergonic and endergonic reactions. During our day-to-day life, we experience both exergonic reactions (releasing more energy than absorbing energy) and endergonic reactions (absorbing more energy than releasing energy). For example, when digesting a snack bar, the energy stored in the food is absorbed into molecules my body uses for fuel, and some of the energy is released as heat. This is exergonic because of catabolism of the food and releasing energy. When I use ice for my drink, the ice cubes melt gradually and make my drink cold. The reaction of ice melting in my drink is endergonic because ice cubes absorb energy from my drink when melting. Given the fact that energy is neither created nor destroyed, very often the energy needed for endergonic reactions comes from exergonic reactions.
    Both these chemical reactions inside our body take time to happen. I wonder if the tempo of the music could represent this. Or maybe they are lively processes and could be well-presented with the tempo you have chosen. It would be more exciting if the relationship between endergonic and exergonic reactions is also included in your music composition

    Robin Bahna

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