Magnetic field induced orientation of photosynthetic systems

Nicholas Geacintov, Francis Van Nostrand, Joseph F. Becker, Jack B. Tinkel

Research output: Contribution to journalArticle

Abstract

1. 1. The fluorescence of aqueous suspensions of Chlorella, Scenedesmus, Euglena and spinach chloroplasts is preferentially polarized in a plane perpendicular to an external magnetic field of 10 kG or more. The ratio of the fluorescence intensity viewed perpendicular to the field to the intensity viewed parallel to the field varies from 1.03 to 1.57. 2. 2. The suspensions also exhibit dichroism and anisotropic wavelength-dependent light scattering effects which are induced by the magnetic field. The dichroic maximum may nearly coincide with the absorption maximum of the bulk pigments and in some cases is shifted to the red by selective light scattering. 3. 3. It is concluded that the dichroism and fluorescence polarization are due to a preferred orientation of the chlorophyll porphyrin rings, and the plane of the lamellae, perpendicular to the field. 4. 4. If it is assumed that the magnetic field does not reorient individual chlorophyll molecules, then these results imply that chlorophyll in vivo possesses a higher degree of orientation than previously thought. 5. 5. It is shown for Chlorella that the magnetic field induces a reorientation of the entire cell. 6. 6. The physical basis of these effects can be adequately explained in terms of an anisotropy in the diamagnetic susceptibility of the cell components. 7. 7. Magnetic field induced orientation can be used to study the optical properties of a large number of suspended oriented cells in vivo.

Original languageEnglish (US)
Pages (from-to)65-79
Number of pages15
JournalBBA - Bioenergetics
Volume267
Issue number1
DOIs
StatePublished - Apr 20 1972

Fingerprint

Magnetic Fields
Magnetic fields
Chlorophyll
Chlorella
Fluorescence
Light scattering
Suspensions
Euglena
Scenedesmus
Light
Fluorescence Polarization
Spinacia oleracea
Anisotropy
Porphyrins
Dichroism
Cellular Structures
Chloroplasts
Pigments
Optical properties
Polarization

ASJC Scopus subject areas

  • Biophysics
  • Medicine(all)

Cite this

Magnetic field induced orientation of photosynthetic systems. / Geacintov, Nicholas; Van Nostrand, Francis; Becker, Joseph F.; Tinkel, Jack B.

In: BBA - Bioenergetics, Vol. 267, No. 1, 20.04.1972, p. 65-79.

Research output: Contribution to journalArticle

Geacintov, Nicholas ; Van Nostrand, Francis ; Becker, Joseph F. ; Tinkel, Jack B. / Magnetic field induced orientation of photosynthetic systems. In: BBA - Bioenergetics. 1972 ; Vol. 267, No. 1. pp. 65-79.
@article{0a6341143c874425af2afa383b352742,
title = "Magnetic field induced orientation of photosynthetic systems",
abstract = "1. 1. The fluorescence of aqueous suspensions of Chlorella, Scenedesmus, Euglena and spinach chloroplasts is preferentially polarized in a plane perpendicular to an external magnetic field of 10 kG or more. The ratio of the fluorescence intensity viewed perpendicular to the field to the intensity viewed parallel to the field varies from 1.03 to 1.57. 2. 2. The suspensions also exhibit dichroism and anisotropic wavelength-dependent light scattering effects which are induced by the magnetic field. The dichroic maximum may nearly coincide with the absorption maximum of the bulk pigments and in some cases is shifted to the red by selective light scattering. 3. 3. It is concluded that the dichroism and fluorescence polarization are due to a preferred orientation of the chlorophyll porphyrin rings, and the plane of the lamellae, perpendicular to the field. 4. 4. If it is assumed that the magnetic field does not reorient individual chlorophyll molecules, then these results imply that chlorophyll in vivo possesses a higher degree of orientation than previously thought. 5. 5. It is shown for Chlorella that the magnetic field induces a reorientation of the entire cell. 6. 6. The physical basis of these effects can be adequately explained in terms of an anisotropy in the diamagnetic susceptibility of the cell components. 7. 7. Magnetic field induced orientation can be used to study the optical properties of a large number of suspended oriented cells in vivo.",
author = "Nicholas Geacintov and {Van Nostrand}, Francis and Becker, {Joseph F.} and Tinkel, {Jack B.}",
year = "1972",
month = "4",
day = "20",
doi = "10.1016/0005-2728(72)90138-7",
language = "English (US)",
volume = "267",
pages = "65--79",
journal = "Biochimica et Biophysica Acta - Bioenergetics",
issn = "0005-2728",
publisher = "Elsevier",
number = "1",

}

TY - JOUR

T1 - Magnetic field induced orientation of photosynthetic systems

AU - Geacintov, Nicholas

AU - Van Nostrand, Francis

AU - Becker, Joseph F.

AU - Tinkel, Jack B.

PY - 1972/4/20

Y1 - 1972/4/20

N2 - 1. 1. The fluorescence of aqueous suspensions of Chlorella, Scenedesmus, Euglena and spinach chloroplasts is preferentially polarized in a plane perpendicular to an external magnetic field of 10 kG or more. The ratio of the fluorescence intensity viewed perpendicular to the field to the intensity viewed parallel to the field varies from 1.03 to 1.57. 2. 2. The suspensions also exhibit dichroism and anisotropic wavelength-dependent light scattering effects which are induced by the magnetic field. The dichroic maximum may nearly coincide with the absorption maximum of the bulk pigments and in some cases is shifted to the red by selective light scattering. 3. 3. It is concluded that the dichroism and fluorescence polarization are due to a preferred orientation of the chlorophyll porphyrin rings, and the plane of the lamellae, perpendicular to the field. 4. 4. If it is assumed that the magnetic field does not reorient individual chlorophyll molecules, then these results imply that chlorophyll in vivo possesses a higher degree of orientation than previously thought. 5. 5. It is shown for Chlorella that the magnetic field induces a reorientation of the entire cell. 6. 6. The physical basis of these effects can be adequately explained in terms of an anisotropy in the diamagnetic susceptibility of the cell components. 7. 7. Magnetic field induced orientation can be used to study the optical properties of a large number of suspended oriented cells in vivo.

AB - 1. 1. The fluorescence of aqueous suspensions of Chlorella, Scenedesmus, Euglena and spinach chloroplasts is preferentially polarized in a plane perpendicular to an external magnetic field of 10 kG or more. The ratio of the fluorescence intensity viewed perpendicular to the field to the intensity viewed parallel to the field varies from 1.03 to 1.57. 2. 2. The suspensions also exhibit dichroism and anisotropic wavelength-dependent light scattering effects which are induced by the magnetic field. The dichroic maximum may nearly coincide with the absorption maximum of the bulk pigments and in some cases is shifted to the red by selective light scattering. 3. 3. It is concluded that the dichroism and fluorescence polarization are due to a preferred orientation of the chlorophyll porphyrin rings, and the plane of the lamellae, perpendicular to the field. 4. 4. If it is assumed that the magnetic field does not reorient individual chlorophyll molecules, then these results imply that chlorophyll in vivo possesses a higher degree of orientation than previously thought. 5. 5. It is shown for Chlorella that the magnetic field induces a reorientation of the entire cell. 6. 6. The physical basis of these effects can be adequately explained in terms of an anisotropy in the diamagnetic susceptibility of the cell components. 7. 7. Magnetic field induced orientation can be used to study the optical properties of a large number of suspended oriented cells in vivo.

UR - http://www.scopus.com/inward/record.url?scp=0015516755&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0015516755&partnerID=8YFLogxK

U2 - 10.1016/0005-2728(72)90138-7

DO - 10.1016/0005-2728(72)90138-7

M3 - Article

C2 - 5019475

AN - SCOPUS:0015516755

VL - 267

SP - 65

EP - 79

JO - Biochimica et Biophysica Acta - Bioenergetics

JF - Biochimica et Biophysica Acta - Bioenergetics

SN - 0005-2728

IS - 1

ER -