Question

Why are hard facts bout photosynthesis? Part of my project is to test my teacher

Answer 1

http://www.ehow.com/about_5434585_photosynthesis.html

Answer 2

The process of photosynthesis mostly takes place in the chloroplasts of plant leaf in mesophyll cells.

Answer 3

The energy for photosynthesis comes from light. This is like sunlight.

Answer 4

the light energy is converted to chemical energy by the chlorophyll.

Answer 5

There are two sets of reactions in photosynthesis. There is light dependent and light independent.

Answer 6

Photosynthesis is affected by a couple factors. Such as temperature, light intensity, light wavelength and carbon dioxide level.

Answer 7

All living things depend on the organic molecules that are synthesised by plants as a result of photosynthesis.

Answer 8

Facts about Photosynthesis
Photosynthesis is the single most important chemical process on earth. It is the process
by which plants use solar energy to manufacture food. The term means “putting together
with light,” and the process of photosynthesis uses solar energy to form simple sugars
from water and carbon dioxide gas. Later these sugars are converted into starch, protein,
or fat; and we eat them as fruits and vegetables. Thus photosynthesis changes light energy
into food (chemical) energy.
Photosynthesis sustains green plants and as a result all other living things as well. Both
directly and indirectly green plants generate most of the world’s chemical energy. Wood
and fossil fuels — coal, oil and natural gas formed from plants and animals that lived mil
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lions of years ago — provide much of our electricity and heat. Green plants are the source
of gasoline that we use to power buses and cars. Fresh fruits, vegetables and grain, as well
as meat from animals that eat plants, give us the energy to work and play and think.
All of this energy originally came from the sun, and it is available to us only as a result of
photosynthesis. People have dreamed of duplicating this process, and biochemists are still
trying to unravel its complexities. They know that it involves a sequence of chemical chang
-
es that takes place in a millionth of a second. They also know that most chlorophyll mol
-
ecules and certain plant pigments act as antennas which receive and absorb solar energy,
then transmit it to a pair of very special chlorophyll molecules that convert it to chemical
energy. When the chemical dynamics of this process are finally understood, people will be
closer to the extraordinary goal of converting sunlight directly to chemical energy. Until that
goal is achieved,
we remain totally dependent on green plants for life.

SOURCE: http://www.homestead-farm.net/art/kidsArt/Photosynthesis%20022806.pdf

Answer 9

Reasons why photosystems are called P680 (photosystem II) and P700 (photosystem I) is because they absorb light most strongly at wavelengths 680 nm and 700 nm, respectively.

Answer 10

Thanks guys!!! :-*

Answer 11

Photosyntehsis is the source of essentially all the carbon compounds - primarily sucrose and starch and all the oxygen that makes aerobic metabolism possble. In general, it follows this stoichiometric equation: \(CO_2 + H_2O _{light} (CH_2O)+O_2\). There's two systems, like someone already pointed out. Photosystems I and II. The major light absorbing pigment is Chlorophyll A, which is a very effectice photoreceptor.

Answer 12

If I were trying to stump your teacher, I would ask some very specific questions, like anything you could draw from this diagram
http://ars.els-cdn.com/content/image/1-s2.0-S0005272811001150-gr1.jpg

Answer 13

You can also ask for the photochemistry of photosystem II with the answer:

"The photochemistry begins with excitation of a special pair of chlorophyll molecules that are bound by the D1 and D2 subunits on the protein complex. The special pair is often called P680, becuase the chlorophyll a molecules of the special pair absorb light at 680 nm. In the momement the excitation of P680 happens, P680 transfers an electron to a nearby pheophytin. From there, the electron is transferred first to a tightly bound plastoquinone at site Qa and then to a mobile plastoquinone at site Qb. With the arrival of a second electron and the uptake of two protons, the mobile plastoquinone is reduced to QH2. At this point, the energy of 2 photons has been safely and efficiently stored in the reducing potential of QH2. in order to optain the electrons in the first place, there is the use of a manganese center. this center consist of a calcium ion and four manganese ions (we belive it was evolutionary selected becuase of all the oxidation states for manganese Mn(II), Mn (III), Mn(IV) and Mn(V), The manganse center in its reduced form oxidizes two molecules of water to form a single molecule of oxygen. Each time the absorbance of a photon kicks an electron out of P680, the positively charged P680 extracts an electron from the manganese center. However we know that the electrons don't come directly form the manganese ions. A tyrosine resideue (called Z) of subunit D1 in photosystem II is the immediate electron donor, forming a tyrosine radical. The tyrosine radical removes electrons from the manganese ions, that remove electrons from water insted forming O2 and protons. We use to say that 4 photons most be absorbed to extract four electrons from a water molecule.
The 2 protons that are taken up with the reduction of Q to QH2 come from the stroma, and the 4 protons that are liberated in the course of water oxidation are released into the lumen. The distribution of protons generates a proton gradient across the thylakoid lumen compared with the stroma."

Or in one sentence: "Photosystem II transfers electrons from water to plastoquinone (Q) and generates a proton gradient".

This is the first half (left side) in @agreene 's diagram.