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tl;dr: Yes, all plants breathe.— I'm not sure whether I understand the question correctly; because all plants use respiration! Some of the organic high-energy substances produced by photosynthesis are later "burnt" to produce energy in the same "respiration" process used by animals, producing CO2. The difference to animals is that green plants ...


44

Chlorophyll absorbs photons (light). The energy in the photon extracts an electron from a molecule of water. Electron transfer creates intermediate superoxide and hydroxyl radicals from the oxygen and hydrogen from the donor water molecule. In normal photosynthesis, these radicals are quickly used to power the reduction of NADP to NADPH and the synthesis ...


39

71% of the earth's surface is taken up by water. Not surprisingly therefore, the seas are an important source of oxygen. National Geographic claims that photosynthesis by phytoplankton (mostly single-celled phototrophs, such as cyanobacteria, green algae and diatoms) account for half of the earth's oxygen production. The other half, they claim, is produced ...


38

There are 5 answers, all "yes" (though the first one is disputable). First: there exists at least one animal which can produce its own chlorophyll: A green sea slug appears to be part animal, part plant. It's the first critter discovered to produce the plant pigment chlorophyll. The sea slugs live in salt marshes in New England and Canada. In ...


31

The vast majority of a tree's carbon comes from the air, which averages 0.03-0.04% by volume (300-400 ppmv) CO2. This is fixed through photosynthesis and eventually stored as glucose which the plant can then use for its metabolism. Doing some quick math, this means that in order to produce 1 kilogram of carbohydrates (e.g. cellulose) a plant needs to ...


29

Short answer It has been shown that plants may already suffer from doubling the atmospheric CO2 concentration from 340 to 610 ppm, something that might happen during the next hundred years or so based on current emissions. Background A popular science website tells us that an excess of carbon dioxide (CO2) reduces the rate of transpiration of some plants. ...


20

Photosynthesis is nearly all visible light. There's usually not enough UV and thermodynamics more or less rules out infrared. Chris covered that pretty spectacularly, but that nearly is significant. There is some evidence that certain kinds of fungi can use gamma rays or other ionizing radiation for energy, but they're not particularly common. Melanin is ...


20

The issue is that it is not always a cycle, when you drain wetlands or burn forests to make more farmland that's not a cycle that is permanent change. A change that can continue having effects for centuries. Then of course you have petroleum fuel used to run tractors and the production of fertilizer which are often not cycles either but pure extraction. ...


18

I'm surprised nobody has mentioned Jan van Helmont. To summarise Blankenship's account, in the 17th century, he (Helmont, not Blankenship) grew a tree in a known dry weight of soil and weighed the fallen leaves of the tree, and then eventually the whole tree including the root system. He found that the mass of the soil had barely diminished and concluded ...


18

Of course they can and do, except in total darkness (spectroscopically, only bands in the far red and in the blue spectra matter - blanking these affects 'total darkness'). In photosynhesis a photon is adsorbed by Photosystem II to break down water into oxygen and protons in solution. Another photon must be adsorbed by Photosystem ! to power the enzymatic ...


17

Photosynthesis only occurs in the visible light.have a look at the absorption spectra of the different pigments involved in photosynthesis, you see that all these pigments absorb light between 400 and 700nm (from a diagram from here): You see that the absorption spectra of chlorophyll a and b are located from 400 to 500nm and again from 630 to 700nm. The ...


17

It depends upon the plant species. As explained in Algae thrive under Pure CO2 Nature 227, pages 744–745 (15 August 1970): Cyanidium caldarium (an algae found in Yellowstone National Park) grows much better in pure carbon dioxide than in air. However, other plants can suffer from acidification of cell fluids at high carbon dioxide concentrations. ...


16

Most of ornamental (often variegated ) plants do performs photosynthesis. They do have chlorophyll even if their color is not green. They have non-green color due to various different pigments. These extra color has their own functions like blocking harsh sunlight or protection from insects (Karageorgou and Manetas 2006). In many non-green plants ...


15

You are missing some knowledge here for sure, photosynthesis is a little complicated at A level, so I will describe it in brief. During photosynthesis electrons and protons (A hydrogen atom without the electron) are required for a process called the electron transport chain and proton motive force. This happens during the light dependent stage of ...


15

Photosynthesis uses chlorophyll (or other pigments) for harnessing photons and water (or other compounds) as electron donor $H_2O = 1/2O_2 + 2H^+ + 2e^-$. After splitting the water it sends the electrons through the further steps of an electron transport chain and at the end it reduces $NADP^+$ into $NADPH$. Meanwhile it increases the $H^+$ concentration ...


15

Besides the unicellular organisms cited by other answers (and the fact that plants actually do respiration), there are some animals who are able to get, although indirectly, energy from photosynthesis through symbiosis with photosynthesizing organisms. You can try the spotted salamander Ambystoma maculatum: The spotted salamander is similar to the sea-...


14

There are two factors at play here. First is the balance between how much energy a plant can collect and how much it can use. It is not a problem of too much heat, but too many electrons. If it were a question of heat, a number of flowers selected for their black pigmentation would have their petals cooked off. ;) If a plant does not have enough water, is ...


14

Short Answer: Any plant can produce oxygen at night, but plants cannot produce oxygen without light. Longer Answer: It all comes down to spontaneity of a reaction i.e. whether a reaction can occur without input of energy or not. Before we talk about spontaneity, I feel it better to first know about the process we're talking about here. In photosynthesis, ...


13

Yes. In fact the organic compounds' mass comes mostly from the air, since Photosynthesis essentially builds up glucose by only adding hydrogen to CO₂. The 2 H₂O → 2H₂ + O₂ reaction can be treated seperately, as was determined by Sam Ruben and Michael Kamen with ¹⁸O isotope tracing, i.e. in fact only the hydrogen in the carbohydrates comes from the soil, and ...


13

As far as I can understand your question, you wish to know why a plant cell consumes ATP to produce glucose when it can directly use the ATP as an energy molecule. ATP is an energy currency and is required in different biochemical pathways. However, it is not a good energy storage molecule. Following are the reasons why production of an energy molecule ...


13

Evolutionary answer: I like to go one step before green plants and consider the humble alga. Algae were historically classified as green, red, and brown, based on the wavelengths that their characteristic pigments absorbed. It is believed that land plants evolved from a common ancestor of algae, so you might wonder why we don't have similar broad categories ...


12

tl;dr: Sort of? Logically, either red or blue light should be sufficient. Chlorophyll a and chlorophyll b preferentially activate different photosystems, and both photosystems are required in green plants. Practically, we're in luck and someone has actually done the experiment. As the original study reports, plants need a little blue light to grow into ...


12

I'm not sure from your question if you're clear on the relationship between carbon fixation and 'energy', so just to be clear: carbon fixation in photosynthesis is the process of capturing CO2 and using it to store light energy in the form of carbohydrates. More CO2 capture = more harvestable 'energy'. Improving the efficiency of photosynthesis therefore ...


11

I'll stick to considering the atmospheric composition, as referred to in the original question: Although there may be some rare exceptions that I can't recall, under normal circumstances all green plants use aerobic respiration with O2 as final electron acceptor for energy production. This means that they require oxygen, which is essentially absent from the ...


11

This is an interesting topic! Crassulacean acid metabolism is a second CO₂ fixation pathway where CO₂ is absorbed at night. The CO₂ is fixed into maleic acid HOOC-CH₂CH(OH)-COOH which stores some of the CO₂ in the form of carboxyl groups. During the day carboxylases release the CO₂ for fixation during the day. This is an adaptation where the stomata ...


11

I know this question was asked and answered a number of years ago (with many great answers), but I couldn't help but notice that no one had approached this from an evolutionary perspective (like the answer to this question)... Short Answer Pigments appear as whatever color is not absorbed (i.e, they appear as whichever wavelength(s) of light they ...


11

Yes they can, but their normal growth is somewhat impaired. A study by Bugbee and collaborators showed that while the yield of rice and wheat increases with CO2 up to about 0.1% CO2, yield decreases sharply as CO2 climbs from 0.1% to 0.25%. There is a smaller loss in yield as CO2 is further increased from 0.25% to 2%. One interesting thing to note about the ...


11

The reason that chlorophyll is green is because it absorbs other colors of light such as red and blue, so in a way the green light is reflected out since the pigment does not absorb it. Because life might have been purple: It is possible that the very first life form to process light may have been purple colored. This would mean it was reflecting red and ...


10

Photosynthetic pigments are the chemicals which take part in photosynthesis, in particular they are they ones which absorb photons and fluoresce (emit photons of a different wavelength) or emit electrons. Pigments are molecules, and chlorophyll is a key example. These pigments are required for photosynthesis to take place, as they generate the electrons ...


10

The biologist John Berman has offered the opinion that evolution is not an engineering process, and so it is often subject to various limitations that an engineer or other designer is not. Even if black leaves were better, evolution's limitations can prevent species from climbing to the absolute highest peak on the fitness landscape. Berman wrote that ...


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