And what is the Emerson effect?
Apparently this:
Robert Emerson
Pioneer of Photosynthesis Research
Emerson was born in 1903 in New York City, the son of Dr. Haven Emerson, Health Commissioner of New York City, and Grace Parrish Emerson, the sister of Maxfield Parrish. Emerson was the brother of John Haven Emerson the inventor of the iron lung.
Emerson received a master’s degree in 1929 from Harvard, and received his doctorate from the University of Berlin working in the laboratory of Otto Warburg
Thomas Hunt Morgan invited him to join the Biology Division at the California Institute of Technology where he worked from 1930 to 1937, and again for a year in 1941 and 1945. From 1942 to 1945 he worked on producing rubber from the guayule shrub for the American Rubber Company.
What is the Emerson Effect?
The Emerson effect, discovered by Robert Emerson is the increase in the rate of photosynthesis after chloroplasts are exposed to light of wavelength 680 nm (deep red spectrum) and more than 680 nm (far red spectrum).
When simultaneously exposed to light of both wavelengths, the rate of photosynthesis is far higher than the sum of the red light and far red light photosynthesis rates. The effect was early evidence that two photo-systems, processing different wavelengths, cooperate in photosynthesis.
When Emerson exposed green plants to differing wavelengths of light, he noticed that at wavelengths of greater than 680 nm the efficiency of photosynthesis decreased abruptly despite the fact that this is a region of the spectrum where chlorophyll still absorbs light (chlorophyll is the green pigment in plants – it absorbs mainly the red and blue wavelengths from light, leaving the green light to bounce back and hit our eyes). When the plants were exposed to short-wavelength light, (less than 660 nm), the efficiency also decreased. Emerson then exposed the plants to both short and long wavelengths at the same time, causing the efficiency to increase greatly. He concluded that there must be two different photosystems involved in photosynthesis, one driven by short-wavelength light and one driven by long-wavelength (PS1 and PS2). They work together to enhance efficiency and convert the light energy to forms that can be absorbed by the plant.
The light excites the chlorophyll molecules at the reaction centre and causes an increase in energy. As the molecule becomes less excited, its energy is transported through a chain of electron carriers to the next photosystem which does much the same thing and produces energy-carrying organic molecules.
