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

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Is there a reason why human eyesight and plants make use of the same wavelength of light?

The accepted range for the wavelengths of light that the human eye can detect is roughly between 400nm and 700nm. Is it a co-incidence that these wavelengths are identical to those in the ...
53
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6answers
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Why do plants have green leaves and not red?

I know plants are green due to chlorophyll. Surely it would be more beneficial for plants to be red than green as by being green they reflect green light and do not absorb it even though green light ...
27
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3answers
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Do trees really get a large share of their mass from the carbon in the air?

I remember hearing that trees and other plants actually obtain a large amount of their mass from the carbon floating in the air, not the ground beneath them. Does the makeup of air actually contain ...
16
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2answers
814 views

Do plant-animal cross races exist?

Plants and animals have the following distinct properties: Plants live from solar energy by photosynthesis, they use solar energy to make sugar and oxygen out of carbon dioxide, which gives them ...
14
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3answers
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NADH vs. NADPH: Where is each one used and why that instead of the other?

I know NADH is used in cellular respiration and NADPH is used in photosynthesis. What difference does the phosphate group make that the same one isn't or can't be used for both? Is there a greater ...
14
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1answer
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How does a plant grow before photosynthesis is possible?

During photosynthesis, a plant translates CO2, water and light into O2. I assume the carbon C is further used for the growing process. I wonder how the plant grows before the time where photosynthesis ...
13
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748 views

Do electromagnetic waves outside the visible spectrum have any role in photosynthesis?

Does photosynthesis occur only in the visible spectrum? If there is a way to completely remove all other electromagnetic bands from the sunlight, including infrared (IR), will photosynthesis continue ...
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How will rising carbon dioxide levels in the troposphere affect photosynthetic producers?

Much discussion has been had about the affects of climate change on plantlife, but how will rising carbon dioxide concentrations affect the photosynthetic process itself? Since CO₂ is a reagent in ...
13
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1answer
112 views

Does a theory exist for the formation of thylakoid structure?

I'm interested in how the structure of the thylakoid forms into its characteristic highly rugose stacks of grana. What causes the thylakoid to invaginate and self-associate, albeit with what appear to ...
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Are trees the only source of large amounts of oxygen?

Trees use carbon dioxide and produce oxygen in the presence of sunlight. But is there any other source? If yes, are trees the most important source of oxygen, or is there any other source which ...
9
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445 views

What vegetation would thrive in the Martian atmosphere? [duplicate]

Most plants require carbon dioxide for their photosynthesis, which Mars has in overabundance. Would atmosphere composition (let's ignore temperatures for the purpose of this question) of Mars allow ...
9
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2answers
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Does Sansevieria trifasciata really absorb Carbon Dioxide at night?

There's a claim that Sansevieria trifasciata (Mother-in-law’s Tongue) generates oxygen from carbon dioxide during the night. This seems surprising to me: that process requires energy; plants generate ...
9
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1answer
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What's the effect of oxygen deficit on plants?

As I know all cells require oxygen. So my question is how efficiently can plants operate in no-oxygen atmosphere? Do all plants produce enough oxygen for themselves? Can they consume their own oxygen ...
8
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1answer
464 views

Can Bioluminescence drive photosynthesis?

I'm trying to construct an anaerobic kitchen-waste digester at home. The major output from the digester is methane - with a significant component of carbon dioxide. To scrub/reduce the CO2 I was ...
7
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2answers
759 views

How do white Caladiums perform enough photosynthesis to support their mass?

In some white caladiums, there is less than a square inch of green space spread over the whole leaf. How do these plants perform the photosynthesis necessary to support the large leaves, the roots, ...
7
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1answer
162 views

Why are there no known photosynthetic archaea?

I'm taking a microbial physiology course and we noted that, while some archaea are phototrophic, there are no known photosynethetic archaea. Are there any physiological characteristics that make ...
7
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2answers
87 views

Exactly which amino acids are phosphorylated in higher plants during state transitions?

I know it is usually stated as the threonine residue near the N-terminus of either light harvesting complex (lhc) b1 or lhcb2, but if this is somehow lost, say in a mutant, is the system flexible ...
7
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1answer
239 views

Compare and contrast “Rubisco activity” and “assimilation rate” (is there a difference, and if so, what is it)?

I am confused about the variable "RuBisCO activity". How is it measured, and is it any different from the net assimilation rate? Based on some background reading (e.g. Kling, 2008; Lambers et al ...
7
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1answer
413 views

Can I estimate leaf temperature from air temperature? What other information would be required?

Physiological measurements such as respiration rate and assimilation rate depend on temperature. Most papers report tissue temperature (e.g. leaf temperature for leaf measurements), although some ...
6
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1answer
444 views

Photosynthetic Pigments vs. Chloroplasts

What is the difference between Photosynthetic Pigments and Chloroplasts? I know plants have both but Prokaryotes (Bacteria and Archeae) only have the former.
6
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1answer
834 views

Do immature fruits perform photosynthesis?

Most immature fruits are green: peppers, pine cones, plums, lots of them. I want to know if the green is from chlorophyll in the cells. Do the fruit cells perform photosynthesis? When you cover a ...
6
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1answer
33 views

What Goes on in Photosystems at the Molecular/Atomic Level?

In light-harvesting complexes, how is the energy of a photon transferred from one pigment molecule to another? And in reaction-center complexes, how does the primary electron acceptor capture an ...
6
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1answer
180 views

Which will produce more oxygen? Less number of (larger) trees or more number of (smaller) plants?

In a given area A, we have two choices - (i) we can plant maximum number of trees (which are larger in size) possible in A, say m OR (ii) we can plant maximum number of plants (which are smaller in ...
5
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3answers
70 views

Why is there a seeming dichotomy between mobility and photosynthesis?

At least among more complex organisms, I cannot think of any examples of highly mobile species (like animals) that also incorporate photosynthesis. Perhaps there are examples that I'm unaware of, but ...
5
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1answer
424 views

Do all plants photosynthesize with equal efficiency?

Just what the title states. Given identical, necessary and favourable conditions (Probably nutrients, humidity, and light but what I mean is all necessary requirements are fulfilled) - Is ...
5
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2answers
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Why does the oxygen produced in the photosynthesis come from water and not CO$_2$?

In the photosynthesis equation $$6*CO_2+6*H_2O+sunlight\rightarrow C_6H_{12}O_6+6*O_2$$ the only place where we have 6 molecules of $O_2$ is in the $6*CO_2$. Then it reacts with $H_2O$ to form ...
5
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1answer
269 views

What is the lowest intensity threshold of light for photosynthesis in any species?

Recently, I was reading the question "Photosynthesis - light intensity, particularly the answer, that states that different species require different intensity of light. My question is what is the ...
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2answers
216 views

How high is the energy yield of photovoltaics compared to photosynthesis?

I'm not an expert in plant physiology. I was wondering if, per square centimeter, leaves are converting more or less energy than photovoltaic systems. Can this be estimated? How?
5
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1answer
62 views

How does CO₂ concentration affect photosynthesis?

I have heard the theory that with the increase of CO2 in the air, the speed of the photosynthesis would increase, thereby limiting the increase of CO2 levels. What is currently the rate limiting ...
5
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1answer
2k views

Does the light color spectrum and frequency matter for photosynthesis?

Do plants grow differently when given sun light, wolfram lamp, fluorescent light, LED light, infrared, ultraviolet, x-ray, unfocused laser and stroboscope?
5
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1answer
94 views

Photosynthesis regulation

I read about the regulation of Calvin cycle by thioredoxin which activates key enzymes essentially by converting disulphide linkages on inactive enzymes into sulfhydryls. Another regulatory mechanism ...
5
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1answer
39 views

Total dark deprivation at day-neutral plants

First of all, I am not a biologist. Almost for a week, a question has come to my mind: "Is it harmful ceaselessly exposing a plant to light?" (I mean with natural & artificial light with ...
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0answers
85 views

Where can I get numerical data for the PAR (photosynthetically active radiation) curve?

I'm trying to do some rough figuring to calculating efficiencies of various light sources for growing plants. I'm hampered, however, by the lack of a curve to multiply by the spectrum of light ...
4
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6answers
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Can we harvest energy from plants?

This is a cross-cutting question but I think its core is about biology. Our society's need for energy is dramatically growing and we are messing up with our environment to answer them. Maybe another ...
4
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2answers
88 views

Is chloroplasts per cell indicative of the photosynthetic power of a plant?

Plant-A has on average N chloroplasts per cell. Plant-B has on average M chloroplasts per cell. If N > M, is plant-A more efficient in turning carbon dioxide into oxygen? Also, is it possible to see ...
4
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1answer
59 views

Why oceans are carbon sinks?

Building on this question, I understand pretty clearly why forests are carbon sinks (trees grow, and there is carbon stored in soil and biomass). What about the oceans, though? Are underwater ...
4
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1answer
3k views

Does photosynthesis require only direct sunlight

I have learned throughout my basic science classes in high school that in the process of photosynthesis, plants absorb sunlight & produce food. They use carbon dioxide & water vapour. My ...
4
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2answers
59 views

Photolysis of Water?

In chemistry, I studied the decomposition of water as being $2H_2O_{(l)} \rightarrow 2H_{2(g)} + O_{2(g)}$. However, when water is split, the equation is $2H_2O_{(l)} \rightarrow 4H^+ + 4e^- ...
4
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1answer
145 views

When is Water Produced During Photosynthesis?

The formula for photosynthesis is: $$6CO_2+12H_2O \rightarrow C_6H_{12}O_6+6O_2+6H_2O$$ I can count the carbons, the waters on the reactant side, the oxygens, and the glucose, but I cannot seem to ...
4
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2answers
158 views

How is photosynthesis observed?

How is photosynthesis observed? Say I have plants A and B, and I want to find how fast they are able to turn carbon dioxide into oxygen. How would I experiment this? Say I have one plant A, which ...
3
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4answers
614 views

Do plants with non-green leaves have chlorophyll and photosynthesis?

Is it even possible that plants with non-green leaves have chlorophyll, and do such non-green leaved plants carry out photosynthesis?
3
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1answer
29 views

Decreasing Solubility as Solvent Moves Higher in Paper Chromatography

In paper chromatography, as the mobile phase (I used 1:9 acetone/petroleum ether) climbs higher and higher, will the solubility of the solutes decrease as the solvent moves higher? I speak mostly ...
3
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2answers
231 views

What does “chlorophyll photosynthesis peak” mean in relation to photon wavelength?

When reading about how green / leafy plants work, I saw that they have chlorophyll A & B, which allow the plant to use the energy from light by capturing and transforming. When reading about ...
3
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1answer
550 views

What types of light can't a plant photosynthesize in?

I have a plant on my desk, and it got me to wondering: Can my plant use the light from my monitors to photosynthesize? If so, what light (apart from green light, to a degree) can't plants use to ...
3
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2answers
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Is there an evolutionary reason for the 5 electron transport complexes in plants and animals?

The electron transport chains of both the light reactions of photosynthesis (in plants) and oxidative phosphorylation (in animals) both contain 5 complexes including ATP synthase, as shown below. ...
3
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1answer
53 views

Where is ATP used in Phosphorylation?

In the section describing the Calvin Cycle, under the subheading "Reduction", my textbook states that: The steps involve utilisation of 2 molecules of ATP for Phosphorylation... I could not get ...
3
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1answer
27 views

How exactly is glyceraldehyde 3-Phosphate reverted to ribulose 1,5-bisphosphate for the continuation of the calvin cycle?

Around 6 molecules of G3P is produced at the end of the Calvin Cycle (light independent reactions of photosynthesis), and 5 of which are reverted back to RuBp. The general equation that I read is 5 ...
3
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1answer
105 views

Where does all the carbon go?

I found it hard to get numbers on global primary production, but apparently it's somewhere around 50-60 $Gt / year$ for carbon content in the terrestrial production, and a similar figure for the ...
3
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1answer
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How Does NADPH Reduce 1,3-BPG?

If NADPH returns to being NADP+, then that means one proton and two electrons have been incorporated into 1,3-BPG. If only one proton and one electron were attached to the carbon in 1,3-BPG (removing ...
3
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2answers
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Would a plant need light if the chemicals gained by photosynthesis were given through the roots or as a foliar spray?

If you took the chemicals a plant gains through photosynthesis and put it through the plants' roots or by injection, or used as a foliar application for intake through the stomata, would the plant ...