BioelectricaAlterspan Labs
Bioenergetics  ·  Article

Enzyme action and stereochemistry

Enzyme action and stereochemistry names a hope that the shape of molecules, and their handedness in particular, would explain how enzymes act. Loeb, writing in 1906, traced the hope to Pasteur and Emil Fischer and said it lasted only for a time.1 The idea matters because it linked molecular geometry to fermentability.2

Earliest held
1896, Wilson, E. B.
Most discussed in
Principles of General Physiology, 1915
In the library
81 passages in 17 works
Rewritten
2026-11-07
18501875190019251950197520002025Loeb, J., 19061Loeb, J., 19062Loeb, J., 19063Henderson, L. J., 19134Bayliss, W. M., 19155Bayliss, W. M., 19156Hill, A. V., 19267Thompson, D. A. W., 19928
01

Pasteur's tartaric acid

Loeb, in The Dynamics of Living Matter (1906), reported Pasteur's founding observation. Early in Pasteur's career, right-handed tartaric acid was easily decomposed by fermentation, and left-handed tartaric acid was not.2 Pasteur assumed, as Loeb puts it, that the geometrical shape of the molecules influences how fermentable a solution is.3 Loeb adds that, according to Pasteur's biography, Pasteur expected important discoveries about the nature of life from this relation. He also says the finding received little attention until Fischer took it up. Loeb credits Fischer with taking up Pasteur's finding through work on yeast fermentation.1

02

Handed molecules and sugars

Henderson (1913) set out the chemistry behind the idea. A carbon atom bearing four different groups is asymmetric and can exist in two forms that resemble each other as the right hand resembles the left. He credited Pasteur, LeBel and van't Hoff, and noted that this adds to the number and variety of organic compounds.4 He gave Fischer's researches as the source of the accepted constitution of glucose. Bayliss (1915) likewise called Fischer's work the chief source of knowledge of the constitution of the sugars.6

03

Selectivity in living tissue

Bayliss reported that tissues are selective among sugars. Dextrose, mannose and galactose are used by intestinal muscle and raise its activity. Fructose is not consumed and does not raise activity.5 He cited Rona and Neukirch (1912) for the intestine. Bayliss does not here attribute this selectivity to molecular handedness. It presents it as a fact the reader needs, with stereochemistry assumed as background knowledge.5

04

Synthesis and physical reality

Thompson, in On Growth and Form, noted a dispute over how handed molecules arise in plants. Under Fischer's conception of asymmetric synthesis, it is now held more likely that the plant builds up one asymmetric body to the exclusion of the other. Japp had supposed instead that the plant picks out one form from an inactive mixture.8 Hill (1926) cited stereochemistry beside atoms and molecules as resting on objective fact, and hoped physiology would follow.7

SourcesEach quotation was checked word for word against the passage it opens.
  1. Certain observations by Pasteur and Emil Fischer seemed, for a time at least, to arouse the hope that the theory of enzymatic action might be found in the field of stereochemistry.Loeb, J., 1906 · The Dynamics of Living Matter · open at passage 72
  2. Pasteur had observed in the beginning of his scientific career that while the right-handed tartaric acid is easily decomposed by fermentation, the same was not true for left-handed tartaric acid.Loeb, J., 1906 · The Dynamics of Living Matter · open at passage 72
  3. Pasteur assumed that the geometri- cal shape of the tartaric acid molecules exercises an influence upon the fermentability of their solution.Loeb, J., 1906 · The Dynamics of Living Matter · open at passage 72
  4. carbon atoms to which four different groups are attached are asymmetric, that is to say, they can exist in two forms which resemble each other as the right hand resembles the left (Pasteur, LeBel, van't Hoff).Henderson, L. J., 1913 · The Fitness of the Environment · open at passage 317
  5. Dextrose, mannose, and galactose are utilised by the intestinal muscle, and increase its activity. Fructose is not consumed, and has no effect in increasing activity.Bayliss, W. M., 1915 · Principles of General Physiology · open at passage 1211
  6. The work of Emil Fischer (1884-1908) has been the chief means of our information of the constitution of the sugarsBayliss, W. M., 1915 · Principles of General Physiology · open at passage 1211
  7. of atoms, molecules and stereochemistry, are based upon real objective fact: we can see the a-particles forming a streak of cloudHill, A. V., 1926 · Muscular Activity · open at passage 145
  8. it is now held to be more likely that the process is synthetic than analytic: more likely, that is to say, that the plant builds up from the first one asymmetric body to the exclusion of the otherThompson, D. A. W., 1992 · On Growth and Form · open at passage 932
Linked ideas
Pasteur is reported to have expected insight into the nature of life from molecular asymmetry, a question the vitalism debate also addressed.
Fitness of the environmentpart of / contains
Henderson's account of asymmetric carbon and the variety of organic compounds appears in his argument about the chemical fitness of the environment.
Which sugars tissue consumes and which it leaves unused is a question of metabolic fate.
Bayliss's sugar-consumption evidence sits alongside work on how glucose is supplied and used.
Thompson's note on asymmetric synthesis comes from On Growth and Form, where handedness in living matter is discussed.
Another early attempt to explain selective behaviour of living matter by physical chemistry rather than by special vital properties.
Where it is discussedPassages matching enzymatic action, stereochemistry, right-handed tartaric acid, Pasteur
1915Principles of General Physiology · Bayliss, W. M.16
1903The Nature of Man: Studies in Optimistic Philosophy · Metchnikoff, E.10
1906The Dynamics of Living Matter · Loeb, J.10
1992On Growth and Form · Thompson, D. A. W.8
1916The Organism as a Whole, from a Physicochemical Viewpoint · Loeb, J.8
1930The History of Biological Theories · Rádl, E.5
1899General Physiology: An Outline of the Science of Life · Verworn, M.4
1923Protoplasmic Action and Nervous Action · Lillie, R. S.4
1957An Introduction to the Study of Experimental Medicine · Bernard, C.4
1900Comparative Physiology of the Brain and Comparative Psychology · Loeb, J.3