Emerson effect
A certain phenomenon in research into photosynthesis is called the Emerson Effect or Enhancement Effect . Simultaneous irradiation with light of two wavelengths causes a higher rate of photosynthesis than the sum of the irradiations with only one of the two wavelengths. The effect is named after its discoverer Robert Emerson .
If unicellular algae or isolated chloroplasts are exposed to monochromatic light with a wavelength of either 680 nm or 700 nm, very specific rates of photosynthesis (O 2 production) are obtained. Simultaneous irradiation with both wavelengths results in a significantly higher photosynthesis rate than the sum of the individual exposures.
This apparently paradoxical result can be explained if one assumes the existence of two photosystems , each with a wavelength-specific reaction center P700 and P680. The maximum rate of photosynthesis can only be achieved when both systems are fully utilized. If only 700 or 680 nm are irradiated, there is a jam in the electron transport chain and no photosystem can work optimally.
literature
- Peter Schopfer, Axel Brennicke: Plant Physiology. Springer-Verlag, 2010. ISBN 9783827423528 . P. 184.
- Lüttge, Ulrich; Kluge Manfred and Bauer, G .: Botany . 5th edition. Wiley-VCH, Weinheim 2005, ISBN 978-3-527-31179-8