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this might seem stupid but i need help on the prosses of photosynthsis

Answer 1

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Photosynthesis is an important biochemical process in which plants, algae, some bacteria, and some protists convert the energy of sunlight to chemical energy. The chemical energy is used to drive synthetic reactions such as the formation of sugars or the fixation of nitrogen into amino acids, the building blocks for protein synthesis. Ultimately, nearly all living things depend on energy produced from photosynthesis for their nourishment, making it vital to life on Earth. It is also responsible for producing the oxygen that makes up a large portion of the Earth's atmosphere. Organisms that produce energy through photosynthesis are called photoautotrophs (as opposed to chemoautotrophs, which convert inorganic chemicals into organic ones which can be used as substrates in respiration). Plants are the most visible representatives of photoautotrophs, but it should be emphasized that bacteria and algae also contribute to the conversion of free energy into usable energy.
Contents
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* 1 Plant photosynthesis
* 2 Photosynthesis in algae and bacteria
* 3 Molecular production
o 3.1 Light to chemical energy
o 3.2 Z scheme
o 3.3 Water photolysis
o 3.4 Oxygen and photosynthesis
o 3.5 Bacterial variations
o 3.6 Carbon fixation
* 4 Discovery
* 5 Bioenergetics of photosynthesis
* 6 Factors affecting photosynthesis
o 6.1 Light intensity (Irradiance), wavelength and temperature
o 6.2 Carbon dioxide
o 6.3 Corollary factors
* 7 In detail
* 8 References
* 9 See also
* 10 External links

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Plant photosynthesis

Most plants are photoautotrophs, which means that they are able to synthesize food directly from inorganic compounds using light energy -for example the sun, instead of eating other organisms or relying on nutrients derived from them. This is distinct from chemoautotrophs that do not depend on light energy, but use energy from inorganic compounds.

The energy for photosynthesis ultimately comes from absorbed photons and involves a reducing agent, which is water in the case of plants, releasing oxygen as a waste product. The light energy is converted to chemical energy (known as light-dependent reactions), in the form of ATP and NADPH, which is used for synthetic reactions in photoautotrophs. Most notably plants use the chemical energy to fix carbon dioxide into carbohydrates and other organic compounds through light-independent reactions. The overall equation for carbon fixation (sometimes referred to as carbon reduction) in green plants is

n CO2 + 2n H2O + ATP + NADPH → (CH2O)n + n O2 + n H2O,

where n is defined according to the structure of the resulting carbohydrate. However, hexose sugars and starch are the primary products, so the following generalised equation is often used to represent carbon reduction.

Carbon Dioxide + Water + Light energy → Glucose + Oxygen + Water

6 CO2 + 12 H2O + ATP + NADPH → C6H12O6 + 6 O2 + 6 H2O

More specifically, carbon fixation produces an intermediate product, which is then converted to the final hexose carbohydrate products. These carbohydrate products are then variously used to form other organic compounds, such as the building material cellulose, as precursors for lipid and amino acid biosynthesis or as a fuel in cellular respiration. The latter not only occurs in plants, but also in animals when the energy from plants get passed through a food chain. Organisms dependent on photosynthetic and chemosynthetic organisms are called heterotrophs. In general outline, cellular respiration is the opposite of photosynthesis: glucose and other compounds are oxidised to produce carbon dioxide, water, and chemical energy. However, both processes actually take place through a different sequence of reactions and in different cellular compartments.

Plants capture light primarily using the pigment chlorophyll, which is the reason that most plants have a green color. The function of chlorophyll is often supported by other accessory pigments such as carotenes and xanthophylls. Both chlorophyll and accessory pigments are contained in organelles (compartments within the cell) called chloroplasts. Although all cells in the green parts of a plant have chloroplasts, most of the energy is captured in the leaves. The cells in the interior tissues of a leaf, called the mesophyll, contain about half a million chloroplasts for every square millimeter of leaf. The surface of the leaf is uniformly coated with a water-resistant, waxy cuticle, that protects the leaf from excessive evaporation of water and decreases the absorption of ultraviolet or blue light to reduce heating. The transparent epidermis layer allows light to pass through to the palisade mesophyll cells where most of the photosynthesis takes place.
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Photosynthesis in algae and bacteria

Algae is a range from multicellular forms like kelp to microscopic, single-celled organisms. Although they are not as complex as land plants, photosynthesis takes place biochemically the same way. Very much like plants, algae have chloroplasts and chlorophyll, but various accessory pigments are present in some algae such as phycoerythrin in red algae (rhodophytes), resulting in a wide variety of colours. All algae produce oxygen, and many are autotrophic. However, some are heterotrophic, relying on materials produced by other organisms. For example, in coral reefs, there is a symbiotic relationship between zooxanthellae and the coral polyps.

Photosynthetic bacteria do not have chloroplasts (or any membrane-bound organelles), instead, photosynthesis takes place directly within the cell. Cyanobacteria contain thylakoid membranes very similar to those in chloroplasts and are the only prokaryotes that perform oxygen-generating photosynthesis, in fact chloroplasts are now considered to have evolved from an endosymbiotic bacterium, which was also an ancestor of and later gave rise to cyanobacterium. The other photosynthetic bacteria have a variety of different pigments, called bacteriochlorophylls, and do not produce oxygen. Some bacteria such as Chromatium, oxidize hydrogen sulfide instead of water for photosynthesis, producing sulfur as waste.

Photosynthesis is affected by its surroundings. The rate of photosynthesis is affected by carbon dioxide, light intensity and the temperature.
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Molecular production
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Light to chemical energy

Main article: Light-dependent reaction

A Photosystem: A light-harvesting cluster of photosynthetic pigments present in the thylakoid membrane of chloroplasts.
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A Photosystem: A light-harvesting cluster of photosynthetic pigments present in the thylakoid membrane of chloroplasts.
The Photosynthetic Process: The Light Dependent Reaction (Non-cyclic and Cyclic Phosphorylation) and the Light Independent Reaction (Calvin Cycle).
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The Photosynthetic Process: The Light Dependent Reaction (Non-cyclic and Cyclic Phosphorylation) and the Light Independent Reaction (Calvin Cycle).

The light energy is converted to chemical energy using the light-dependent reactions. The products of the light dependent reactions are ATP from photophosphorylation and NADPH from photoreduction. Both are then utilized as an energy source for the Light independent reactions.
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Z scheme

In plants, the light dependent reactions occur in the thylakoid membranes of the chloroplasts and use light energy to synthesize ATP and NADPH. The light dependent reaction has two forms; cyclic and non-cyclic reaction. In the non-cyclic reaction, The photons are captured in the light-harvesting antenna complexes of photosystem II by chlorophyll and other accessory pigments (see diagram at right). When a chlorophyll molecule at the core of the photosystem II reaction center obtains sufficient excitation energy from the adjacent antenna pigments, an electron is transferred to the primary electron-acceptor molecule, Phaephytin, through a process called Photoinduced charge separation. These electrons are shuttled through an electron transport chain, the so called Z-scheme shown in the diagram, that initially functions to generate a chemiosmotic potential across the membrane. An ATP synthase enzyme uses the chemiosmotic potential to make ATP during photophosphorylation while NADPH is a product of the terminal redox reaction in the Z-scheme. The electron enters the Photosystem I molecule. The electron is emitted due to the light absorbed by the photosystem. A second electron carrier accepts the electron, which again is passed down lowering energies of electron acceptors. The energy created by the electron acceptors is used to move hydogen ions across the thylakoid membrane into the lumen. The electron is used to reduce the co-enzyme NADH, which has functions in the light-independent reaction. The cyclic reaction is similar to that of the non-cyclic, but differs in the form that it only generates ATP and no reduced NADP (NADPH) is created. The cyclic reaction takes place only at photosystem I. Once the electron is displaced from the photosystem, the electron is passed down the electron acceptor molecules and returns back to photosystem I, from where is was emitted. Hence the name, cyclic reaction.
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Water photolysis

The NADPH is the main reducing agent in chloroplasts, providing a source of energetic electrons to other reactions. Its production leaves chlorophyll with a deficit of electrons (oxidized), which must be obtained from some other reducing agent. The excited electrons lost from chlorophyll in photosystem I are replaced from the electron transport chain by plastocyanin. However, since photosystem II includes the first steps of the Z-scheme, an external source of electrons is required to reduce its oxidized chlorophyll a molecules. The source of electrons in green-plant and cyanobacterial photosynthesis is water. Each water molecule is oxidized by four successive charge-separation reactions by photosystem II to yield a molecule of diatomic oxygen and four hydrogen ions; the electron yielded in each step is transferred to a redox-active tyrosine residue that then reduces the photooxidized paired-chlorophyll a species called P680 that serves as the primary (light-driven) electron donor in the photosystem II reaction center. The oxidation of water is catalyzed in photosystem II by a redox-active structure that contains four manganese ions; this oxygen-evolving complex binds two water molecules and stores the four oxidizing equivalents that are required to drive the water-oxidizing reaction. Photosystem II is the only known biological enzyme that carries out this oxidation of water. The hydrogen ions contribute to the transmembrane chemiosmotic potential that leads to ATP synthesis. Oxygen is a waste product of light-independent reactions, but the majority of organisms on Earth use oxygen for cellular respiration, including photosynthetic organisms.
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Oxygen and photosynthesis

With respect to oxygen and photosynthesis, there are two important concepts.

* Plant and cyanobacterial (blue-green algal) cells also use oxygen for cellular respiration, although they have a net output of oxygen since much more is produced during photosynthesis.
* Oxygen is a product of the light-driven water-oxidation reaction catalyzed by photosystem II; it is not generated by the fixation of carbon dioxide. Consequently, the source of oxygen during photosynthesis is water, not carbon dioxide.

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Bacterial variations

The concept that oxygen production is not directly associated with the fixation of carbon dioxide was first proposed by Cornelis Van Niel in the 1930s, who studied photosynthetic bacteria. Aside from the cyanobacteria, bacteria only have one photosystem and use reducing agents other than water. They get electrons from a variety of different inorganic chemicals including sulfide or hydrogen, so for most of these bacteria oxygen is not produced.

Others, such as the halophiles (an Archaea) produced so called purple membranes where the bacteriorhodopsin could harvest light and produce energy. The purple membranes was one of the first to be used to demonstrate the chemiosmotic theory: light hit the membranes and the pH of the solution that contained the purple membranes dropped as protons were pumping out of the membrane.
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Carbon fixation

Main article: Carbon fixation

The fixation or reduction of carbon dioxide is a light-independent process in which carbon dioxide combines with a five-carbon sugar, ribulose 1,5-bisphosphate (RuBP), to give two molecules of a three-carbon compound, glycerate 3-phosphate (GP). This compound is also sometimes known as 3-phosphoglycerate (PGA). GP, in the presence of ATP and NADPH from the light-dependent stages, is reduced to glyceraldehyde 3-phosphate (G3P). This product is also referred to as 3-phosphoglyceraldehyde (PGAL) or even as triose phosphate (a three-carbon sugar). This is the point at which carbohydrates are produced during photosynthesis. Some of the triose phosphates condense to form hexose phosphates, sucrose, starch and cellulose or are converted to acetyl-coenzyme A to make amino acids and lipids. Others go on to regenerate RuBP so the process can continue (see Calvin-Benson cycle).
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Discovery

Although some of the steps in photosynthesis are still not completely understood, the overall photosynthetic equation has been known since the 1800s.

Jan van Helmont began the research of the process in the mid-1600s when he carefully measured the mass of the soil used by a plant and the mass of the plant as it grew. After noticing that the soil mass changed very little, he hypothesized that the mass of the growing plant must come from the water, the only substance he added to the potted plant. This was a partially accurate hypothesis - much of the gained mass also comes from carbon dioxide as well as water. However, this was a signalling point to the idea that the bulk of a plant's biomass comes from the inputs of photosynthesis, not the soil itself.

Joseph Priestley, a chemist and minister, discovered that when he isolated a volume of air under an inverted jar, and burned a candle in it, the candle would burn out very quickly, much before it ran out of wax. He further discovered that a mouse could similarly "injure" air. He then showed that the air that had been "injured" by the candle and the mouse could be restored by a plant.

In 1778, Jan Ingenhousz, court physician to the Austrian Empress, repeated Priestley's experiments. He discovered that it was the influence of sun and light on the plant that could cause it to rescue a mouse in a matter of hours.

In 1796, Jean Senebier, a French pastor, showed that CO2 was the "fixed" or "injured" air and that it was taken up by plants in photosynthesis. Soon afterwards, Nicolas-Théodore de Saussure showed that the increase in mass of the plant as it grows could not be due only to uptake of CO2, but also to the incorporation of water. Thus the basic reaction by which photosynthesis is used to produce food (such as glucose) was outlined.

Modern scientists built on the foundation of knowledge from those scientists centuries ago and were able to discover many things.

Cornelis Van Niel made key discoveries explaining the chemistry of photosynthesis. By studying purple sulfur bacteria and green bacteria he was the first scientist to demonstrate that photosynthesis is a light-dependent redox reaction, in which hydrogen reduces carbon dioxide.

Further experiments to prove that the oxygen developed during the photosynthesis of green plants came from water, were performed by Robert Hill in 1937 and 1939. He showed that isolated chloroplasts give off oxygen in the presence of unnatural reducing agents like iron oxalate, ferricyanide or benzoquinone after exposure to light. The Hill reaction is as follows:

2 H2O + 2 A + (light, chloroplasts) → 2 AH2 + O2

where A is the electron acceptor. Therefore, in light the electron acceptor is reduced and oxygen is evolved.

Samuel Ruben and Martin Kamen used radioactive isotopes to determine that the oxygen liberated in photosynthesis came from the water.

Melvin Calvin and Andrew Benson, along with James Bassham, elucidated the path of carbon assimilation (the photosynthetic carbon reduction cycle) in plants. The carbon reduction cycle is known as the Calvin cycle, which inappropriately ignores the contribution of Bassham and Benson. Many scientists refer to the cycle as the Calvin-Benson Cycle, Benson-Calvin, and some even call it the Calvin-Benson-Bassham (or CBB) Cycle.

A Nobel Prize winning scientist, Rudolph A. Marcus, was able to discover the function and significance of the electron transport chain.
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Bioenergetics of photosynthesis
This section is a stub. You can help by adding to it.

Photosynthesis is a physiological phenomenon that converts solar energy into photochemical energy. This physiological phenomenon may be described thermodynamically in terms of changes in energy, entropy and free energy. The energetics of photosynthesis, driven by light, causes a change in entropy that in turn yields a usable source of energy for the plant.

The following chemical equation summarizes the products and reactants of carbon reduction in the typical green photosynthesizing plant:

CO2 + H2O → O2 + (CH2O) + 112 kcal/mol

On earth, there are two sources of free energy: light energy from the sun, and terrestrial sources, including volcanoes, hot springs and radioactivity of certain elements. The biochemical value of electromagnetic radiation has led plants to use the free energy from the sun in particular. Visible light, which is used specifically by green plants to photosynthesize, may result in the formation of electronically excited states of certain substances called pigments (Gregory). For example, Chlorophyll a is a pigment which acts as a catalyst, converting solar energy into photochemical energy that is necessary for photosynthesis (Govindjee).

With the presence of solar energy, the plant has a usable source of energy, which is termed the free energy (G) of the system. However, thermal energy is not completely interconvertible, which means that the character of the solar energy may lead to the limited convertibility of it into forms that may be used by the plant. This relates back to the work of Josiah Willard Gibbs: the change in free energy (ΔrG) is related to both the change in entropy (ΔrS) and the change in enthalpy (ΔrH) of the system (Rabinowitch).

Gibbs free energy equation: ΔrG = ΔrH – TΔrS... where ΔH is enthalpy, ΔS is entropy, and T is temperature.

Past experiments have shown that the total energy produced by photosynthesis is 112 kcal/mol. However in the experiment, the free energy due to light was 120 kcal/mol. An overall loss of 8 kcal/mol was due to entropy, as described by Gibbs equation (Govindjee). In other words, since the usable energy of the system is related directly to the entropy and temperature of the system, a smaller amount of thermal energy is available for conversion into usable forms of energy (including mechanical and chemical) when entropy is great (Rabinowitch). This concept relates back to the second law of thermodynamics in that an increase in entropy is needed to convert light energy into energy suitable for the plant.

Overall, in conjunction with the oxidation-reduction reaction nature of the photosynthesis equation, and the interrelationships between entropy and enthalpy, energy in a usable form will be produced by the photosynthesizing green plant.
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Factors affecting photosynthesis

There are three main factors affecting photosynthesis and several corollary factors. The three main are:

* Light irradiance and wavelength
* Carbon dioxide concentration
* Temperature

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Light intensity (Irradiance), wavelength and temperature

In the early 1900s Frederick Frost Blackman along with Gabrielle Matthaei investigated the effects of light intensity (irradiance) and temperature on the rate of carbon assimilation.

* At constant temperature, the rate of carbon assimilation varies with irradiance, initially increasing as the irradiance increases. However at higher irradiance this relationship no longer holds and the rate of carbon assimilation reaches a plateau.
* At constant irradiance, the rate of carbon assimilation increases as the temperature is increased over a limited range. This effect is only seen at high irradiance levels. At low irradiance, increasing the temperature has little influence on the rate of carbon assimilation.

These two experiments illustrate vital points: firstly, from research it is known that photochemical reactions are not generally affected by temperature. However, these experiments clearly show that temperature affects the rate of carbon assimilation, so there must be two sets of reactions in the full process of carbon assimilation. These are of course the light-dependent 'photochemical' stage and the light-independent, temperature-dependent stage. Secondly, Blackman's experiments illustrate the concept of limiting factors. Another limiting factor is the wavelength of light. Cyanobacteria which reside several meters underwater cannot receive the correct wavelengths required to cause photoinduced charge separation in conventional photosynthetic pigments. To combat this problem a series of proteins with different pigments surround the reaction center. This unit is called a phycobilisome.
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Carbon dioxide
This section is a stub. You can help by adding to it.

As carbon dioxide concentrations rise, the rate at which sugars are made by the light-independent reactions increases until limited by other factors. One reason for this is that RuBisCO, the enzyme fixing the carbon dioxide in the light-dependent reactions, has a binding affinity for both carbon dioxide and oxygen. Thus, an increase in the concentration of carbon dioxide increases the probability of RuBisCO fixing carbon dioxide instead of oxygen.

A reduced RuBisCO oxygenase activity is advantageous to plants for several reasons.

1. One product of oxygenase activity is phosphoglycolate (2 carbon) instead of 3-phosphoglycerate (3 carbon). Phosphoglycolate cannot be metabolized by the Calvin-Benson cycle and represents carbon lost from the cycle. A high oxygenase activity, therefore, drains the sugars that are required to recycle ribulose 5-bisphosphate and for the continuation of the Calvin-Benson cycle.
2. Phosphoglycolate is quickly metabolized to glycolate that is toxic to a plant at a high concentration; it inhibits photosynthesis.
3. Salvaging glycolate is an energetically expensive process that uses the glycolate pathway and only 75% of the carbon is returned to the Calvin-Benson cycle as 3-phosphoglycerate.

A highly simplified summary is:

2 glycolate + ATP → 3-phophoglycerate + carbon dioxide + ADP +NH3

The salvaging pathway for the products of RuBisCO oxygenase activity is more commonly known as photorespiration since it is characterized by light dependent oxygen consumption and the release of carbon dioxide.
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Corollary factors
This section is a stub. You can help by adding to it.

* Amount of water
* Leaf morphology
* Leaf nitrogen content
* Molecular carriers such as NADP and FAD

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In detail

Metabolic pathways involved in photosynthesis:

* Light-dependent reaction
* Light-independent reaction

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References

* Blankenship, R.E., 2002. "Molecular Mechanisms of Photosynthesis". Blackwell Science.
* Campbell, N., & Reece, J., 2005. Biology 7th ed. San Francisco: Benjamin Cummings.
* Gregory, R.P.F., 1971. Biochemistry of Photosynthesis. Belfast: Universities Press.
* Govindjee, 1975. Bioenergetics of Photosynthesis. New York: Academic Press.
* Govindjee; Beatty, J.T., Gest, H. and Allen, J.F. (Eds.), 2005. Discoveries in Photosynthesis. Advances in Photosynthesis and Respiration, Volume 20, Springer.
* Rabinowitch, E. and Govindjee., 1969. Photosynthesis. New York: John Wiley & Sons, Inc.


Good luck.

Answer 2

Photosynthesis

Photosynthesis is the process of converting light energy to chemical energy and storing it in the bonds of sugar. This process occurs in plants and some algae (Kingdom Protista). Plants need only light energy, CO2, and H2O to make sugar. The process of photosynthesis takes place in the chloroplasts, specifically using chlorophyll, the green pigment involved in photosynthesis.

Photosynthesis takes place primarily in plant leaves, and little to none occurs in stems, etc. The parts of a typical leaf include the upper and lower epidermis, the mesophyll, the vascular bundle(s) (veins), and the stomates. The upper and lower epidermal cells do not have chloroplasts, thus photosynthesis does not occur there. They serve primarily as protection for the rest of the leaf. The stomates are holes which occur primarily in the lower epidermis and are for air exchange: they let CO2 in and O2 out. The vascular bundles or veins in a leaf are part of the plant's transportation system, moving water and nutrients around the plant as needed. The mesophyll cells have chloroplasts and this is where photosynthesis occurs.



As you hopefully recall, the parts of a chloroplast include the outer and inner membranes, intermembrane space, stroma, and thylakoids stacked in grana. The chlorophyll is built into the membranes of the thylakoids.

Chlorophyll looks green because it absorbs red and blue light, making these colors unavailable to be seen by our eyes. It is the green light which is NOT absorbed that finally reaches our eyes, making chlorophyll appear green. However, it is the energy from the red and blue light that are absorbed that is, thereby, able to be used to do photosynthesis. The green light we can see is not/cannot be absorbed by the plant, and thus cannot be used to do photosynthesis.

The overall chemical reaction involved in photosynthesis is: 6CO2 + 6H2O (+ light energy) C6H12O6 + 6O2. This is the source of the O2 we breathe, and thus, a significant factor in the concerns about deforestation.

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There are two parts to photosynthesis:

The light reaction happens in the thylakoid membrane and converts light energy to chemical energy. This chemical reaction must, therefore, take place in the light. Chlorophyll and several other pigments such as beta-carotene are organized in clusters in the thylakoid membrane and are involved in the light reaction. Each of these differently-colored pigments can absorb a slightly different color of light and pass its energy to the central chlorphyll molecule to do photosynthesis. The central part of the chemical structure of a chlorophyll molecule is a porphyrin ring, which consists of several fused rings of carbon and nitrogen with a magnesium ion in the center.

The energy harvested via the light reaction is stored by forming a chemical called ATP (adenosine triphosphate), a compound used by cells for energy storage. This chemical is made of the nucleotide adenine bonded to a ribose sugar, and that is bonded to three phosphate groups. This molecule is very similar to the building blocks for our DNA.


The dark reaction takes place in the stroma within the chloroplast, and converts CO2 to sugar. This reaction doesn't directly need light in order to occur, but it does need the products of the light reaction (ATP and another chemical called NADPH). The dark reaction involves a cycle called the Calvin cycle in which CO2 and energy from ATP are used to form sugar. Actually, notice that the first product of photosynthesis is a three-carbon compound called glyceraldehyde 3-phosphate. Almost immediately, two of these join to form a glucose molecule.

Most plants put CO2 directly into the Calvin cycle. Thus the first stable organic compound formed is the glyceraldehyde 3-phosphate. Since that molecule contains three carbon atoms, these plants are called C3 plants. For all plants, hot summer weather increases the amount of water that evaporates from the plant. Plants lessen the amount of water that evaporates by keeping their stomates closed during hot, dry weather. Unfortunately, this means that once the CO2 in their leaves reaches a low level, they must stop doing photosynthesis. Even if there is a tiny bit of CO2 left, the enzymes used to grab it and put it into the Calvin cycle just don't have enough CO2 to use. Typically the grass in our yards just turns brown and goes dormant. Some plants like crabgrass, corn, and sugar cane have a special modification to conserve water. These plants capture CO2 in a different way: they do an extra step first, before doing the Calvin cycle. These plants have a special enzyme that can work better, even at very low CO2 levels, to grab CO2 and turn it first into oxaloacetate, which contains four carbons. Thus, these plants are called C4 plants. The CO2 is then released from the oxaloacetate and put into the Calvin cycle. This is why crabgrass can stay green and keep growing when all the rest of your grass is dried up and brown.

There is yet another strategy to cope with very hot, dry, desert weather and conserve water. Some plants (for example, cacti and pineapple) that live in extremely hot, dry areas like deserts, can only safely open their stomates at night when the weather is cool. Thus, there is no chance for them to get the CO2 needed for the dark reaction during the daytime. At night when they can open their stomates and take in CO2, these plants incorporate the CO2 into various organic compounds to store it. In the daytime, when the light reaction is occurring and ATP is available (but the stomates must remain closed), they take the CO2 from these organic compounds and put it into the Calvin cycle. These plants are called CAM plants, which stands for crassulacean acid metabolism after the plant family, Crassulaceae (which includes the garden plant Sedum) where this process was first discovered.

Answer 3

Sunlight goes into plants, plants convert sunlight to energy, and the energy is food for the plants to grow.

Look at the wikipedia entry for details.

Answer 4

Photosynthesis is cool,man.

Answer 5

I think those guys and gals have it pretty much covered.

Answer 6

Its simple... its just about plants!

..

Answer 7

you lazy a_s...you just got hooked up...citations and everything.

Answer 8

my goooooodness !!!!!!!!! not sure if there was any room after that !!

Answer 9

sorry i dont know what to do???

Answer 10

no