The entropy generation in visual-pigment system by the absorption of light

Etsuro Ito*, Toshiro Komatsu, Hideo Suzuki

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


We first showed a general theory that reception of information from the outside in a receptor system is accompanied both by an inflow of entropy and by a generation of entropy depending on the reliability of the actual reception mechanism. Then, considering a case for the absorption of light by the visual-pigment system of visual cell, we calculated the time(t)-dependent change in the number N2(t) of excited visual-pigments to obtain the entropy increase. We thus arrived at the following four conclusions: (1) One or two photons can be detected with a reliability of at least 54%; (2) In compensation for this detection, entropy > 1.12 x log2 is generated; (3) An incident photon of frequency v from a light source of temperature T(s) yields an entropy of hv/T(s); and (4) Depending on the characteristics of the visual-pigment system, another entropy being different from (2) is generated in proportion to N2(t).

Original languageEnglish
Pages (from-to)59-70
Number of pages12
JournalBiophysical Chemistry
Issue number1
Publication statusPublished - 1998 Aug 4
Externally publishedYes


  • Information theory
  • Molecular orbital theory
  • Negentropy
  • Photoisomerization
  • Photoreception
  • Second law of thermodynamics

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Organic Chemistry


Dive into the research topics of 'The entropy generation in visual-pigment system by the absorption of light'. Together they form a unique fingerprint.

Cite this