and chlorophyll biosynthesis in dark ..

Another misunderstanding about LED emitters is targeting the responsive wavelength. While exact coral responsiveness wavelengths are unknown, much is known in a more broad sense (and even more knowledge is growing, such as the "blue band" of coral responsiveness). For example, we do know that much of the yellow and green bands are 30%-80% less efficient for most photosynthetic corals, clams, etc. (although under 24% green light can be useful, but over 25% it is actually detrimental; Reference: )

Light and dark modulation of chlorophyll biosynthetic genes in ..

Light and dark modulation of chlorophyll biosynthetic genes ..

What is photosynthesis? - eschooltoday



Let us see now how protists and other little animals of ponds react to alteration to theirenvironment.
1 - Some microscopic algae, like the euglena, search out light (phototaxis) and to do thisthey use an organelle sensible to the light, named stigma. With a dark paper, cover thebottom part of a test tube holding a culture of euglena. The part of the test tube exposedto light should become green, rich with algae. Make the same experiment with othermicroscopic algae and with protozoa.
2 - Add two or three drop of distilled water to a little water drop collected in a pondand watch what happens to the protists. Very probably you will see them inflate and thenexplode. This occurs because of the different saline concentration inside and outside theprotists and the osmotic pressure which is produced inside their cells.
3 - Protists are sensitive to most chemicals and generally they react by running away; insome cases instead they approach them (chemotaxis). Prepare some microscope slides withprotists and observe through the microscope their behavior when you add acidic substances(i.e.: vinegar), basic substances (i.e.: backing soda), glucose, salt, sparkling water(rich of CO2), broth, milk, tiny grain of cheese, dyes, etc. At thebeginning use very low amounts of these substances, then increase their concentration.
4 - From a pond or an aquarium, collect a hydra and place it on a microscope slide with apair of water drops. Observing this tiny polyp through the microscope, probably you willsee some sucker shaped microorganisms (trichodina) moving on its body. Watch what happensafter adding a little drop of vinegar to their water! Trichodina will escape from thehydra and probably die. Hydra itself will have launched many of its harmful paralyzingdarts.
5 - Submit protists to different stimulus such as light, temperature, electric field(about 5 V in DC). In this last case, some protists will gather on the cathode (thenegative - pole). Also amebas are inclined to move towards the cathode. Change thepolarity of the current and observe the behavior of the protists.
Internet Keyword: phototaxis chemotaxis protists.

Chlorophyll (also chlorophyl) is ..

These same older generation emitters, controller technology & drivers are the reason I did not recommend LEDs of ANY brand for "higher-end" aquarium applications until 2008 (readers of this VERY constantly evolving article in 2007 would note this too).
However NOW we have many reef/planted aquarium capable LED lights and the only thing that separates most are bells & whistles, cost, efficiency of energy input to output, colors one might desire (albeit not necessarily what the photosynthetic life is more efficient utilizing), water proofing/resistance, and warranty. Even in cost, often the other factors will override an initially low cost of many popular LED fixtures.

Both these examples demonstrate how photosynthesis and plant growth obviously favors photons of specific frequencies!
What is photosynthesis?

Role of Light and Chlorophyll in Starch Synthesis | …

The picture above depicts both full solar radiation that reaches the earth as well as how a few different man-made light sources fit into the visible/PAR aspect of this spectrum.
What is noteworthy is how much radiation falls outside the PAR, in particular the longer frequency wave lengths going into radio waves. There is much that we also do not know, since photosynthetic plants, zooanthellic algae, etc. might also be using radiant energy we do not know about. What we do know is that since UVC is not reaching the earth's surface and that even UVB only reaches in small amounts (if at all during certain times of the day and seasons), that it is likely this is mostly useless for our application.

Free photosynthesis process review. Study chloroplasts, the chemical equation, chlorophyll and the light and dark stages of photosynthesis.

the chlorophyll and light have ..

N2 - Excision of the embryonic axis prior to 3 1/2 days of germination in the dark followed by 8‐h of light decreased the total chlorophyll content of cucumber cotyledons but not squash cotyledons. Benzyladenine stimulated the accumulation of chlorophyll in the cotyledons of intact embryos and excised cotyledons in both cucumber and squash. Gibberellic acid had no effect. Atrazine inhibited chlorophyll formation in excised squash cotyledons. Benzyladenine also increased the carotenoid and xanthophyll content in the cotyledons from intact squash seedlings. The results suggest that pigment synthesis in cotyledons may be controlled by a number of substances produced in the embryonic axis and that cytokinin‐like benzyladenine can simulate the action of one of them.

Chlorophyll synthesis in dark-grown pine primary needles Author: Schoefs, B., Franck, F. Source: Plant physiology 1998 v.118 no.4 pp. 1159-1168 ISSN:

the light-dependent and the dark ..

Excision of the embryonic axis prior to 3 1/2 days of germination in the dark followed by 8‐h of light decreased the total chlorophyll content of cucumber cotyledons but not squash cotyledons. Benzyladenine stimulated the accumulation of chlorophyll in the cotyledons of intact embryos and excised cotyledons in both cucumber and squash. Gibberellic acid had no effect. Atrazine inhibited chlorophyll formation in excised squash cotyledons. Benzyladenine also increased the carotenoid and xanthophyll content in the cotyledons from intact squash seedlings. The results suggest that pigment synthesis in cotyledons may be controlled by a number of substances produced in the embryonic axis and that cytokinin‐like benzyladenine can simulate the action of one of them.