In Cellular respiration, glucose(C₆H₁₂O₆) and oxygen(O₂) are used to make carbondioxide(CO₂) and water(H₂O).

C₆H₁₂O₆+O₂ –> CO₂+H₂O

In Photosynthesis, carbondioxide and water are used to produce glucose(C₆H₁₂O₆) and oxygen(O₂).

CO₂+H₂O –> C₆H₁₂O₆+O₂

The overall equation for aerobic cellular respiration is the opposite of that for photosynthesis:

energy (ATP)+ 6 CO₂ + 6 H₂O <== C₆H₁₂O₆ + 6 O₂ (cellular respiration)

energy (light) + 6 CO₂ + 6 H₂O ==> C₆H₁₂O₆ + 6 O₂ (photosynthesis)

Cellular respiration occurs in the mitochondria, oxidation of glucose occurs, energy and carbon dioxide are released. It requires oxygen and occurs in both plants and animals, day or night.

Photosynthesis occurs in the chloroplast, reduction occurs, energy and oxygen are released while requiring carbon dioxide.

Light Wavelength: Red and blue wavelengths are most effective for photosynthesis. Green (500nm) is least effective.

Light Intensity: Photosynthesis is faster in more intense light until limited by some other factor. Once the reactions are going as fast as they can, more intense light has no effect.

Humidity: If the humidity is low, the stomata will close to reduce water loss through transpiration. Closed stomata limit gas exchange, and photosynthesis is slowed by a reduction in carbon dioxide availability.

Temperature: The rate of photosynthesis increases with temperature. Above the optimum temperature for photosynthetic enzyme function, photosynthesis is inhibited or shut down completely.

Carbon Dioxide Concentration: More carbon dioxide in the air allows more photosynthetic conversion into sugar, until limited by another factor.

Water: Compared to the amount of water needed to sustain a plant, the amount needed for photosynthesis is small. However, a dehydrated plant cannot perform efficient photosynthesis.

Composite image showing the global distribution of photosynthesis, including both oceanic phytoplankton and land vegetation.

1. outer membrane
2. intermembrane space
3. inner membrane (1+2+3: envelope)
4. stroma (aqueous fluid)
5. thylakoid lumen (inside of thylakoid)
6. thylakoid membrane
7. granum (stack of thylakoids)
8. thylakoid (lamella)
9. starch
10. ribosome
11. plastidial DNA
12. plastoglobule (drop of lipids)

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. Two water molecules are 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 photoxidized 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 and a calcium ion; 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-dependent reactions, but the majority of organisms on Earth use oxygen for cellular respiration, including photosynthetic organisms.

The reason why nanowires are used is the fact that they have the ability to break down water molecules into hydrogen and oxygen. The nanowires make artificial photosynthesis very efficient, something that the scientific community has been after for years.

Scientists believe that being able to have this capability included inside a battery would be one of the first and also most important steps towards obtaining efficient and affordable chemical storage abilities.

Using this technology it may be possible to develop storage materials that could contain the electric energy output of power plants utilizing alternative energy.

Such facilities, which either run on wind or sunlight, only output energy during the day, or during periods of high wind, respectively, which means they don’t have a steady production capability.

Taking this line of though a step further, this means that national power grids are placed under a lot of strain every time alternative energy facilities kick into gear.

The excess power can damage grid components, and also destabilize the system as a whole. But having storage devices of the aforementioned nature could ensure that this never happens again.

Basically, research team are moving towards creating a system that would ensure electricity produced by solar power plants and wind farms is being fed into the grid gradually, and a constant pace.

The new wires play an important role in this because they can imitate one of nature’s essential phenomenon, photosynthesis. Using this process, plants convert carbon dioxide into oxygen, allowing for complex life to exist on this planet.

The new constructs are made out of titanium dioxide (TiO2), and have large surface areas. This allows for them to be mounted on sensors that absorb ultraviolet (UV) lights, and also to increase the latter’s efficiency.

A clear paleontological window on cyanobacterial evolution opened about 2000 Ma, indicating an already-diverse biota of blue-greens. Cyanobacteria remained the main producers throughout the Proterozoic Eon (2500-543 Ma), because the redox structure of the oceans favored photoautotrophs capable of nitrogen fixation.

Green algae joined blue-greens as major primary producers on continental shelves near the end of the Proterozoic, but only with the Mesozoic (251-65 Ma) dinoflagellates, coccolithophorids, and diatoms did primary production in marine shelf waters take modern form.

Cyanobacteria play an essential role in marine ecosystems as primary producers in oceanic gyres, as agents of biological nitrogen fixation, and, in modified form, as the plastids of marine algae.

This new type of chlorophyll named ‘chlorophyll f’ is found in stromatolites–rock-like structures built by cyanobacteria in Western Australia‘s Shark Bay. The new pigment can utilize lower light energy than other known types of chlorophyll. It is the fifth known type of chlorophyll.

The discovery was announced by Dr. Min Chen, a scientist working at the University of Sydney. “Discovering this new chlorophyll has completely overturned the traditional notion that photosynthesis needs high energy light,” Chen said.

Chlorophyll is the green colored pigment that in found in the leaves of plants. It is also found in many bacteria. It enables plants to trap the energy of sunlight and convert it into carbohydrate by absorbing carbon dioxide from the atmosphere. Photosynthesis is a crucial process for the sustenance of life on our planet.

Via: English.News.cn

Air pollution can affect photosynthesis adversely. For example, smog can block out light that is needed for photosynthesis, affecting photosynthesis through which plants convert CO₂ to sugars and oxygen.

Air pollution can also cause “acid rain.” Acid rain is a popular term for the atmospheric deposition of acidified rain, snow, sleet, hail, acidifying gases and particles, as well as acidified fog. Acid rain harms the leaves of a plant, which reduces how well it can conduct photosynthesis.

Carotenoids present in green leaves can absorb the upper frequency band of the visible light spectrum i.e. violets, blue, dark green frequencies. Since leaves also contain carotenoids, plants will be able to perform photosynthesis but only to a small extent.

Stored energy wouldn’t be used for photosynthesis, or at least the light reactions – note the light reactions are the ones that use light energy to generate ATP and NADPH. The dark reactions use these molecules to generate oxygen and sugars. Stored energy would most likely undergo respiration to generate energy from pre-existing sugars.