Photoyynthesis

What is photosynthesis?

Photosynthesis is a biochemical process in which plants, green algae,
and some bacteria use the energy of light to combine water and
carbon dioxide into oxygen and energy. It nourishes nearly all living
things directly or indirectly, making it vital to life on Earth

Plants, green algae, and some bacteria are autotrophs, which means that they they sustain themselves without eating other organisms or substances derived from other organisms. Autotrophs produce their raw organic molecules from carbon dioxide (CO2) and other inorganic raw materials derived from the environment.

Photosynthesis is the process by which these autotrophs (such as plants, green algae and some bacteria) use the energy contained in sunlight to split carbon dioxide and water, and recombine them into oxygen gas and a sugar called glucose. Glucose (C6H12O6) is a simple molecule that is used by autotrophs for many things, such as fuel to make energy, and building material to make cellulose (which is used by plants to make their rigid cell walls).

The overall chemical reaction of photosynthesis is:

12H2O + 6CO2 + light ? C6H12O6 (glucose) + 6O2 + 6H2O

In simple English, water plus carbon dioxide plus light energy yields sugar plus oxygen plus water. This is the exact opposite of the process of respiration in animals: oxygen plus sugar yields carbon dioxide plus water plus energy. Even though this reaction may seem simple, the details of photosynthesis are actually very complex.

• from http://en.wikipedia.org/wiki/Photosynthesis

'A NATURAL APPROACH to electricity. Plants do it. Solar cells do it.
Why can't solar cells do it like plants do? Logical question --
once you realize that "it" means using sunlight to create free electrons.'

see also PhotoVoltaics

• http://whyfiles.org/shorties/photosyn.html

PhotoSynthesis Art

Grass under the dark areas of the projected negative, where
photosynthesis is subdued, is pale yellow. Under the lighter areas,
where plenty of light shines through and photosynthesis is more
rigorous, the grass is a deeper green. The grass image itself
develops slowly over days as the young blades mature.

There is an ephemeral, delicate quality to these chlorophyll photographs.
Once the projected negative is removed the yellow areas start darkening
to green. Ackroyd and Harvey wanted their artwork to last a little longer
and turned to the Institute of Grassland and Environmental Research
(IGER) in Wales for help.

Artists: Heather Ackroyd and Dan Harvey

• http://www.artsadmin.co.uk/artists/ah/photosynthesistext.html#Grass%20Tapestry
• http://www.shanatinglipton.com/grass2.html

-- RachelWingfield - 03 Nov 2004
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