Mechanismen der Erregung von Lichtsinneszellen
214. Sitzung am 7. März 1973 in Düsseldorf
PAYBACK Punkte
0 °P sammeln!
After the absorption of light, the visual pigment - rhodopsin, a chromo protein - undergoes a cascade of reactions. One of these reactions triggers conductivity changes in the membrane of the visual cell. This alteration in conductivity causes modifications of the ionic currents which result in a transient voltage impulse across the cell membrane. The height of this voltage signal is dependent on light intensity. The electrochemical mechanism which generates the voltage impulse is different in the visual cells of verte brates and invertebrates. Though the molecular mechanism of visual excita t...
After the absorption of light, the visual pigment - rhodopsin, a chromo protein - undergoes a cascade of reactions. One of these reactions triggers conductivity changes in the membrane of the visual cell. This alteration in conductivity causes modifications of the ionic currents which result in a transient voltage impulse across the cell membrane. The height of this voltage signal is dependent on light intensity. The electrochemical mechanism which generates the voltage impulse is different in the visual cells of verte brates and invertebrates. Though the molecular mechanism of visual excita tion is not yet understood, its elucidation can be approached in the near future. Resume La lumiere en excitant l'reil est absorbee par le pigment retinien - ou rhodopsine, soit une chromoproteine, et entra~ne une reaction en cha~ne dans les cellules photoreceptrices: l'absorption d'un photon declenche une reaction photochimique de la rhodopsine suivie d'une serie de reactions se deroulant independamment de la lumiere. L'un des stades de la reaction provoque par un mecanisme encore inconnu dans sa majeure partie, une alteration momentanee de la conductibilite de la membrane photoreceptrice.
Andere Kunden interessierten sich für
