Questions tagged [photosynthesis]

The process by which light energy is harnessed to assemble organic compounds (esp. glucose) from inorganic carbon dioxide.

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Does the Bacteria culturing medium effect its performance?

Different mediums are used to culture different bacteria species in a Lab environment. I noticed that there is not one optimal medium for every bacteria. I am more curious about culturing ...
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Blooming at moonlight

At the moment a popular question in the physics SE community is about night-blooming cereus: this flower blooms at full moon, that is it is capable of making difference between the moonlight and ...
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Amount of carbon captured in photosynthesis by a plant

Is it more proportional to the mass or the volume of the plant? I thought it might be helpful to think on the cellular level here. Even a reference to an external explanation would be useful.
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Is averaged molar CO2 and O2 output/input necessarily identical?

Do we take up identical amounts of oxygen to the amounts of CO2 that we output? Equivalently, do plants take up identical amounts of CO2 as they release O2? (moles, averaged over >24 hours) I was ...
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What is special about Pulse-Amplitude-Modulation (PAM) fluorometry?

I know that PAM fluorometry is used to measure chlorophyll fluorescence and understand the principle of those measurements. It is in principle clear to me from prior research in the literature, that ...
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What genes are required to make E. coli photosynthetic?

"All" of the genes for bacterial photosynthesis were discovered in a gene cluster almost 40 years ago. Marrs, J.Bact. What more is needed to make E. coli photosynthetic?
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CAM Photosynthesis Oxygen Generation?

I've been looking into CAM plants - notably the snake plant which is native to West Africa. Upon researching the CAM photosynthesis cycle, I've found it fascinating that the plant stores CO2 at night ...
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Structure and reactions of the cofactors of oxidoreductases such as ferredoxin

I have seen the word flavoprotein being used in place of ferredoxin in few places and vice-versa. I have not found any source that mentions them both together and explains the relation between them. ...
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Calvin cycle- combining three “turns”

In the common Calvin cycle diagram, it is commonly stated that "three cycles are combined to show the production of 1 molecule of G3P". How does the G3P molecule escape from this cycle in ...
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Is there a known efficiency rate for CO2 capture from ambient air in photosynthesising plants?

When humans take in air to their lungs, we capture about 5% of the total quantity of the air as oxygen (which in turn equals about 24% of the available oxygen in the air) Is there an equivalent rate ...
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Light intensity effect on plant transpiration

In the graph of light intensity versus rate of transpiration, the rate increases up to a certain point but then remains constant. What is the reason that it stays constant, is there a limiting factor ...
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How do the High-Energy Electrons During Chemiosmosis Come from Water?

On Pg. 199 of Campbell, this is stated. Both* work by way of chemiosmosis, but in chloro- plasts, the high-energy electrons dropped down the transport chain come from water, while in mitochondria, ...
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How come only a handful of animals can do photosynthesis?

As far as I understand, all the energy that living beings rely on comes from the sun. It's processed by plants in photosynthesis. These plants are consumed by herbivores, which in turn are consumed by ...
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Do fish depend on plants for survival?

As far as I know, all land life depends on plants for survival. Plants convert sunlight to energy using photosynthesis, herbivores consume plants, and carnivores consume herbivores. All the energy is ...
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Why doesn't the rate of photosynthesis increase with increasing light energy (frequency)? [duplicate]

Why doesn't the rate of photosynthesis increase with increasing light energy (frequency)? I know that green light is not absorbed by chlorophyll, yet I am confused as to why this certain "...
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How many times did photosynthesis evolve?

Was it a 1 and done thing? Plants seem to have developed photosynthesis by the endosymbiosis of cyanobacteria. Is the latter the one time in Earth's history that the process independently came about? ...
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Can we achieve complete photosynthesis on a petri dish? Barriers and potential

If we were to place bacteriorhodopsin and ATP synthase in an acidified solution (for H+ ions) filled with phospholipids, ADP and inorganic phosphate, hopefully the bacteriorhodopsin and ATP synthase ...
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Are there any fluorescent proteins capable of transforming 500-600 nm light to 400-500 or 600-700 nm?

In order to improve photosynthesis, which doesn't use 500-600 nm light, I wonder if that light can be transformed into useful light? The idea is to transfect photosynthesis organisms with the gene for ...
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What part, roughly, of the carbon in a plant comes from the soil? As opposed to the atmosphere?

C4 plants contain a slightly higher percentage of carbon-13 than C3 plants. Is this because of carbon obtained from the soil or the atmosphere? I have read that plants using different chemical ...
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Can we produce sugar using chlorophyll dissolved in ethanol?

I can't find anything about this on the net. I read in my (high-school) textbook that if plants get sunlight, water and carbon dioxide, and the catalyst called chlorophyll, they can make sugar. I'm ...
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Is this question about limiting factors answerable?

This is from a Singapore-Cambridge GCE O-level Biology exam (a national exam for 16-year-olds). The exam board maintains that the question is "correct and accurate"—but isn't there a typo in ...
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How does the light-independent stage of photosynthesis get H+ ions?

From what I understand from my grade 11 biology: During the light-dependent stage of photosynthesis, water molecules split, producing hydrogen and oxygen atoms. The oxygen atoms are basically “waste ...
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How is Elysia chlorotica classified as an animal capable of photosynthesis?

Elysia chlorotica is a kind of sea slug. Technically, it's an animal. However, it undergoes a process called kleptoplasty, which is the absorption of chloroplasts from algal prey cells which are then ...
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How quickly are plants able to sense changes in light intensity?

Evidently due to the process of photosynthesis, plants are able to "sense" light (as demonstrated by the phototropic response). My question is, how quickly are plants able to perceive ...
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Is there such a thing as an autotroph that doesn't use photosynthesis?

I've heard of photoautotrophs, which are just autotrophs that use photosynthesis. What I'm wondering is if there's any other way for an organism to make its own food that doesn't involve it using ...
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Phytomass and photosynthesis

I have been introduced to the term "phytomass" and I was wondering if phytomass can be both photosynthetic and non-photosynthetic?
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Is there any study to find the plant with the absolute minimum light need?

Is there any study to find plants with absolute minimum light need? Consider a bathroom without windows that you have occasional artificial light (e.g. white LED light). Another question is there ...
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Do plants take in the same amount of CO2 as they release?

There are many claims in the media that trees remove more carbon dioxide form the atmosphere than they release back into the atmosphere. By what chemical pathway can this occur? The law that matter is ...
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Do plant cells recycle carbon dioxide from their respiration during photosynthesis? [duplicate]

It seems one of my colleague's biology textbook claims that plant cells, with presence of light, feed back 100% of carbon dioxide molecules from their respiration into photosynthesis. Can you say that ...
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Why do quaking aspens quake?

I've just finished reading The Hidden Lives of Trees by Peter Wohlleben, which I thoroughly enjoyed. According to the author, the advantage of shaking the leaves is that both sides of the leaf are ...
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Does photosynthesis begin instantly when a plant is exposed to light?

I'm curious to know if the process of photosynthesis has a "ramp-up" time to become useful to a plant, or if it begins instantaneously when the plant is exposed to light after a period of darkness. ...
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Nitrogen deficiency and chloroplast function

Q. The formation of which of the following in the chloroplast is affected by a deficiency in nitrogen? (a) Glyceraldehyde 3-phosphate (b) Starch (c) Enzymes (d) Carbohydrates My thoughts: Nitrogen ...
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Could Cyanobacteria farms help dilute pollutants in the atmosphere

If I understand correctly, roughly ~2.8 billion years ago cyanobacteria started pumping large amounts of oxygen into the atmosphere. Using modern industrial processes could this be emulated by ...
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Do plants refix some of the carbon dioxide in the Calvin cycle that they produce through cellular respiration?

Plants do cellular respiration and release CO2 into the air, but does the plant also use some of this CO2 to do the Calvin cycle? Or does all the CO2 required for the Calvin cycle come in through the ...
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Photolysis in the Light Reactions of Photosynthesis [duplicate]

I'm a bit confused concerning photolysis. During the light reactions, photons are used to excite the chlorophyll molecules so they are passed to the primary electron acceptor. The electrons initially ...
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Why does atrazine kill photosynthetic bacteria and not nonphotosynthetic bacteria?

Atrazine was found to bind to Qb, which is involved in electron transport to create ATP in photosynthetic bacteria. Why does this herbicide kill photosynthetic bacteria, while having little to no ...
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Plant respiration produces carbon dioxide, so why are plants regarded as decreasing its atmospheric concentration?

In the absence of sunlight, plants give out the greenhouse gas, carbon dioxide. So why is it said that plants increase the concentration of atmospheric oxygen? Do they not increase the concentration ...
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Effect of light intensity on the frequency of stomata

According to this article, the frequency of stomata increases with an increase in the intensity of light. What I inferred from this is, since the rate of photosynthesis increases at higher light ...
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How is C4 pathway more water efficient than C3 pathway in photosynthesis?

In the C3 pathway: 1 H2O molecule is required for the fixation of 1 CO2 molecule. In the C4 pathway: The only H2O molecule used is in the calvin cycle, so 1 H2O molecule required for fixation of 1 ...
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Photosynthesis production of oxygen [closed]

If you are to increase the intensity of light indefinitely, would you expect the production of oxygen to continue to increase?
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Photosynthesis immature fruits [duplicate]

Do immature fruits perform photosynthesis? Yes they have chlorophyll bodies. But do they have stomata through which they can absorb carbondioxide like the green leaves? Sincerely Ulrik
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Why have plants evolved to photosynthesize glucose instead of another molecular compound?

I think this question can be broken down into two sub-questions: Why do plants produce $C_6H_{12}O_6$ as opposed to another molecule following the formula of $C_nH_{2n}O_n$? Why not $C_8H_{16}O_8$, $...
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Chorophyll and photosynthesis in plants with coloured leaves

Do plants that have only coloured leaves (e.g. ‘ornamental’ plants) contain chlorophyll and perform photosynthesis? If they don’t, how do they obtain energy and metabolic intermediates?
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How many electrons does the b6-f complex need to pump one proton into the thylakoid lumen?

In photosynthesis, photons are used through photolysis to split water molecules and retrieve their hydrogen ions and electrons in the water-splitting complex. For each four photons, two water ...
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what is the integral of PAR radiation over total solar radiation

This paper say 48%: What is the maximum efficiency with which photosynthesis can convert solar energy into biomass? -Zhu 2008 Also why does Zhu use 740 nm at high end of PAR wavelength! My ...
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Which complexes physically pump protons in photosynthesis?

The cytochrome b6f complex is often drawn as pumping protons, but then someone told me that actually there is no pumping, rather the Q cycle. According to this view, what actually moves the protons ...
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How does the emerson effect produce a higher rate of photosynthesis?

Can anyone explain how the emerson effect works to increase the rate of photosynthesis, and as the original studies were done over 50 years ago, how much research is still done into this area? Or is ...
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Is coral photosynthesis dependant on the wavelength or frequency of light?

When buying a light fixture for a marine fish tank, it is often sold with some technical data reguarding the spectral output of the light, with a peak in the blue region of visible light, somewhere ...
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Why “Having chlorophyll without photosynthesis is actually very dangerous” and “like living with a bomb”?

The Phys.org article Scientists discover first organism with chlorophyll genes that doesn't photosynthesize says "For the first time scientists have found an organism that can produce ...
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Photosynthesis: Can light directly excite the reaction center instead of going through the antenna complex?

The reaction centers that I am interested in are P680(photosystem II) and P700 (photosystem I) Here is what I think: If pigments such as chlorophyll a and b capture light in the antenna complex, and ...

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