G18.00003. The electron's spin and chirality, the source for quantum effects in biology
Presented by: Ron Naaman
Sponsoring Units: GSNP Chair: Clarice Aiello Slides: https://drive.google.com/file/d/1ZyyhozSr18MiC4ZMS5dhQgNLN572cuf4 While the charge of the electron is known to play a major role in biological processes, and charge transfer was investigated extensively, it is usually assumed that the electron’s spin does not play any important role. We found that chiral organic molecules can act as spin filters in electron transfer. The new effect, termed Chiral Induced Spin Selectivity (CISS), was found, among others, in bio-molecules and in bio-systems. In nature, very important molecules like proteins and sugars, are chiral. Chiral molecules lack mirror symmetry and they appear in two forms, enantiomers, that are not imposable on each other. Interestingly, all chiral molecules in nature appear basically in one enantiomeric form, while the other form is missing. The issue of the origin of homo chirality in nature is under extensive debate. Independent on its origin, the question is “why evolution preserves chirality ?” Another related question is why electron transfer in Biology occurs through proteins, that are bad conductors, and not through conjugated molecules for example. In other word, an important question is if the chirality in bio-molecule serves specific functions that cannot be fulfilled with achiral molecules. Based on the CISS effect, it will be shown that indeed chirality is essential for many functions in biology and this “topological” property is used by nature at physiological relevant temperatures.
- Ron Naaman