Sci Question

Is there some special reason why photosynthesis has picked the color green ?

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youtube.com/watch?v=aAQYpra4aUs
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ebscohost.com/uploads/imported/thisTopic-dbTopic-1033.pdf
pcp.oxfordjournals.org/content/50/4/684.full
en.wikipedia.org/wiki/Black_pearl_pepper
usna.usda.gov/Research/BlackPearl.html
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It's more appropriate to say green is the color photosynthesis rejected.

Chlorophyll??

More like BORE-a-phyll.

jej, this

There's a scientific american article about this.
It's about what color foliage would be on planets with different types of stars.

IIRC most power from the Sun is green light.

Yes, in fact!

The light-using part of photosynthesis involves splitting water into hydrogen and oxygen. The photon required to do this in a single step would be far too energetic, so instead it captures one photon to move the molecule into an excited state, and then another to break the bond. Because of the quantum mechanics of electron transitions, only photons of a specific energy can perform these transitions; specifically, you need a red photon and a blue photon.

Once you take out the red and blue from sunlight, you're left with green. (There's not enough violet in sunlight to matter compared to the green light). If plants were black, they would overheat, so they simply reflect the green part of sunlight.

So if what you both say is right, plants have evolved in a way to use a less energized solar beams. Whouldn't that mean that they could propably evolve to be totally black?

youtube.com/watch?v=aAQYpra4aUs
youtube.com/watch?v=545rqaOJQD8

Ah! Because if they absorbed green photons as well, they would have all the colors absorbed and thus go all black and overheat as you say. Noice!

What said is that the Sun irradiates mostly green light (light with wavelength at around 500nm, which we perceive as green), NOT that green is the most energised type of light. Blue light has more energy for example. The type of light a star emits is dependent on its type.

Forget that for now. Focus on our Sun. It emits all of the wavelengths, but mostly green. Plants use both blue (very energised) as well as red (least energised). The thing is that due to the atmosphere scattering sunlight, the surface where plants live get a lot of blue and red light depending on the time of day, not so much green, so they evolved to utilise blue and red, rather than green. If the plants, with their current cell architecture, used all wavelengths, as said, they would overheat, therefore not viable. The thing to keep in mind is that once something extremely beneficial evolves (photosynthesis using blue and red light) it will spread very fast and dominate, while natural selection creating a theoretically more energy dependent, bigger plant would not be favoured. Do you understand now?

If the "typical earth plant" runs into trouble trying to absorb all wavelengths due to thermal management issues,
then rejecting some other arbitrary portion of the spectrum, not green only, might suffice. No ?

...

here's the article: ebscohost.com/uploads/imported/thisTopic-dbTopic-1033.pdf
pretty good read.

it didnt fucking pick green it picked blue and some red.what you're seeing is that it didnt 'pick'.
as for why it just so happens that some microbes evolved all sorts of photosynthesis processes and the one nearly all plants use today is the best one so far and it uses green chlorophyll .

also the most scattered wavelengths of light in the atmosphere are the most energetic(bluer) and so plants using it will get the most energetic photons from atmospheric light .

> It's more appropriate to say green is the color photosynthesis rejected.

Photosynthesis has not rejected green. Some 50% - 80% of green light is actually used, just in a seemingly less efficient manner.

I have no way of telling if you are bull shit ting or not. But GREAT answer !

It picked red - blue using chlorophyll.
It also picked green using rhodopsin. This was the first type that occurred and it still exists in nature.

...many spectra of absorptance (the absolute value of light absorption) measured with integrating spheres have shown clearly that ordinary,
green leaves of land plants absorb a substantial fraction of green light (McCree 1972, Inada 1976, Gates 1980).

It is also known that green light, once absorbed by the leaves, drives photosynthesis with high efficiency (Björkmann 1968, Balegh and Biddulph 1970, McCree 1972, Inada 1976).
On an absorbed quantum basis, the efficiency or photosynthetic quantum yield of green light is comparable with that of red light, and greater than that of blue light.

pcp.oxfordjournals.org/content/50/4/684.full

Thank you for taking the time to explain, I understand perfectly now!

>If plants were black, they would overheat
>thus go all black and overheat as you say
>they would overheat, therefore not viable

This is all baloney.

let the brainlets believe their theories. It's all they have

>the niggers of the plant kingdom
they are all equal even though they evolved in vastly different enviroments :^)

Actually, it seems this plant didn't evolve naturally, it was developed in a lab.
en.wikipedia.org/wiki/Black_pearl_pepper

> Actually, it seems this plant didn't evolve naturally, it was developed in a lab.
meaning..... what ? , in the context of the discussion ?

I think he wants to point the fact that plants naturally evolve to be green only, not black.

The blackbody radiation curve of the sun peaks in the green. That's not quite the same as saying most of the power from the sun is green.

You can calculate the peak for the blackbody radiation curve of anything if you know the temperature that it radiates. You can also calculate the temperature at which anything radiates by knowing the amount of energy it receives using the Steffan-boltzmann energy balance equation

Steffan-boltzmann equation

I was just poking innocent fun at the sarcastic comment about the nigger analogy.

Also, according to: usna.usda.gov/Research/BlackPearl.html
The leaves in the designer plant are a deep purple shade that is very close to black. I'd bet the way they did this is to increase anthocyanin pigment levels (purple in some cases), which is used by leaves to protect from too much sunlight and photoinhibition of photosynthesis. These plants still use chlorophyll exclusively for energy production, which absorbs blue and red, it just probably has a lot more anthocyanin. It doesn't use all the wavelengths for energy production.

I could be very wrong, of course, but that would be my best explanation at a quick glance.

I think the other guy meant to point out that black leaved plants, might have evolved, naturally in spite of the "overheating theory".

...

Does this mean that I can modify the plant to add a pathway for vitamin b12 and get rich like the golden rice thingie?

Not unless you have a giant multinational behind you with several billion to sink into the obtuse regulations

> Is there some special reason why photosynthesis has picked the color green ?
Yes.

The Atmospheric Theory

Plants receive incidental light from the sun primarily in two ways:
light shining directly from the sun through the atmosphere, and, ambient light from a variety of reflection and scattering processes in the plant's environment.
In the case of more direct bright sunlight falling on a plant, the light is a relatively full spectrum white light. That is, there is not a lot
of bias towards a single color as any child can tell you about our sun. In fact, a dull orange is the preferred color of a non-pure-white sun - NOT GREEN.
So an evolving plant confronted with just this type of light would not necessarily have have a strong need to bias towards a particular color scheme such as
the green chlorophyll process that we actually see being used by over 99% of the plant kingdom.

It is the second incidental light source that will introduce the bias.

Consider the [pic related]. It is dificult to find any green in the sky in sample pictures that show common lighting conditions for plants on earth.
We have always the chance for the bright white direct sunlight and some white clouds neither of which is a strong color bias.
It is the red and blue that seem to jump out as the unique non-full-spectrum colors available to the plants.
So we have a bias towards red and blue in the overall available light for a typical plant !
Since there is less green in the lighting available, the plant is more free to reflect it through the green color of the leaves.

>I'd bet
there is no wagering at Veeky Forums, Grandpa

>any child can tell you
>because their eyes are perfect spectrometers
gtfo fgt pls

stop telling children the sun is made of green cheese

what the fuck is this all about then ?

Perhaps a a rogue non-conformer.

>it didnt fucking pick green it picked blue and some red.what you're seeing is that it didnt 'pick'.

I love it when 'inverting' a thought makes it clearer

green is also the color which has the "most hues" relative to red and blue, on a site note

>plants overheat

FUCK YOU. Plants are not computers!

yeah they just die, how dare him not memento mori.