Photosynthesis - Science topic
The synthesis by organisms of organic chemical compounds, especially carbohydrates, from carbon dioxide using energy obtained from light rather than from the oxidation of chemical compounds. Photosynthesis comprises two separate processes: the light reactions and the dark reactions. In higher plants; GREEN ALGAE; and CYANOBACTERIA; NADPH and ATP formed by the light reactions drive the dark reactions which result in the fixation of carbon dioxide. (from Oxford Dictionary of Biochemistry and Molecular Biology, 2001)
Questions related to Photosynthesis
Light (PAR) is necessary for photosynthesis. But how to calculate the minimum amount of sunlight necessary for the expected growth of a crop( no crop loss ) and beyond this PAR the plant is considered to be subjected to low light stress?
Is there any paper of systematic protocol?
I have plenty of data from leaves, but is there a way to calculate their photosynthesis rate?
I count with:
- Leaf temperature
- Leaf VPD
- Stomatal conductance and density (stomata/cm2) and their % aperture
- RH & Temperature from the environment
- Irradiation from the sun (W/m2)
- PAR Light
I know that the best way to obtain photosynthesis rate is with a enclosed chamber and measure the decrease of CO2, but is there a way to calculate it with some of the data that I already have?
I have been searching for a mathematical model or any kind of coupled equations, but I haven't found any info.
Thanks in advance.
photosynthesis depends on the light energy captured by the chlorophyll pigments, this green light is made up of three Green-Red and Blue bands.can infiltration of light energy damage cells to cause leaf senescence?
I'm trying to figure out how to measure chlorophyll/unit leaf area and photosynthesis/unit chlorophyll, and I have DMSO and SPAD chlorophyll data. If you have any suggestions, please let me know.
I need some good papers which can explain the above-asked question. I need to know what exactly LRCs tell about the photosynthesis in plants which is not covered by chlorophyll fluorescence alone. If anyone can explain in simple words (with some references), it would be highly appreciable.
In addition to transpiration and assimilation, which physiological, anatomical or morphological traits you think could have significant impact on water use efficiency in plants?
Moreover which WUE assessment technique you find to be the most robust and representative?
Stomata are pore spaces that allow for the exchange of gases and water. Is it possible to increase stomatal density to help in photosynthesis?
To construct an theoretical framework to balance cost of carbon gain at the expense of water, it was interpreted that Michaelis constant plays crucial role in developing model. However, there are numbers of publications just described this parameters in one line with no complete description which is confusing for followers. Please me to help get out of this confusion with suggestions and answers.
Thanks in advance
Hello. I've been working on photosynthesis pigment content in in vitro grown trees and was examining the formulas for determining the concentration of chlorophyll a and b and carotenoids based on absorbance, i.e. using a spectrophotometer. I've found various formulas, and even though they all share the same general design: concentration=coefficient1*adsorbance1-coeficeint2*adsorbance2, the coefficients differ among sources. I was curious as to the reason behind this. Is it due to the use of different equipment, i.e. every spectrophotometer is different, or something else? I'm new to this field, thus any help, directions to relevant introductory literature, articles, would be great.
Trees have different effects on the climate directly or indirectly. These effects emanate from trees’ reactions to varying climate-related factors. Factors such as greenhouse gases emission, production and emission of aerosols, albedo (whiteness), carbon and nitrogen deposition, transpiration and photosynthesis can affect the speed of climate change.
I am working on photosynthesis mechanisms on a new alga strain that has no previous studies and want to separate a special LHC under a specific light enviornment. At first, I want to compare the protein on the thylakoid membrane of this strain with Chlamydomonas reinhardtii by SDS-PAGE, therefore to determine the specific protein of each band. However, I found this is not accurate unless I undertake immunoblotting steps further. If I use BN-PAGE to separate complex first and to compare the result with C. reinhardtii, is it possible for me to determine these complexes on the thylakoid membrane and find the special LHC by following 2D-PAGE electrophoresis?
I am working on a synthetic biology project in which I am redesigning the pathways in photosynthesis of Synechococcus elongatus to become more efficient, evaluated by increase in biomass. We want to computationally model this in R but we are struggling to find packages that can help us with this. I've looked at deSolve::aquaphy which models C and N assimilation but photosynthesis rate is an input and we want to model this also.
I am looking for a model that corresponds to the photosynthesis of a plant (with the physiological signal). Please, does anyone have a clue ?
micro plastic contamination will reduce sunlight penetration and affect the photosynthesis activities and other impact. do have any report or case studies in this regard
I am trying to do photosynthetic response curves at different leaf temperatures in Montreal trees. The goal is to measure from 25 to 40˚C using a Licor 6400XT. When I increase the temperature, the block can achieve until 38˚C, but the leaf temperature never exceeds ~31-32˚C. In many articles I see curves until 40˚C, can someone recommend me a technic to increase the leaf temperature or how to exceed 31˚C in the leaf temperature.
Thanks so much!
Light is inevitable for the process of photosynthesis reaction. Naturally sunlight plays the vital role for this process. Light may be of different colours like white, red, yellow, blue etc. However, is the rate of photosynthesis depend on different colour?
Does the shade of green in plants affect the rate of sunlight needed for survival. Can deeper green shaded plant tolerate more lowlight.
we are looking to buy a photosynthesis meter that can potentially measure photosynthetic rate, stomatal conductance, CO2 assimilation, PS1 and PSII efficiency (if possible), etc. it would be great if the experts in the field can give their opinion that will save our time and money. please drop a link if you know about something.
Do iron salts increase photosynthesis, or do they increase the size of chloroplasts, or cytochromes when iron is sufficient? In other words, is greening-up functional or structural under these conditions?
There is plenty of research showing how iron deficient plants will "green up" when Fe2+ is applied, usually attributed to increased photosynthesis. Unfortunately, iron is typically over-applied to golf course greens entirely for aesthetic purposes. As a result, Cr, Cu, Mn, Mo, Si, W, and Zn are antagonized, increasing susceptibility to disease, followed by over-application of pesticides.
As it is not directly my field, I would like to ask for help in terms of the correlation between light intensity, wavelength, frequency and amplitude.
Let's say, I have a radiophotometer which measures the light intensity of 3 different light source with different wavelengths (blue, green, red). They are all set to 100 umol m-2 s-1 photon flux.
I am using these conditions to algae culturing.
My question is the following;
if blue light has shorter wavelength, higher frequency, therefore higher energy than red light, although intensity is set to equal (100 umol m-2 s-1),
Is it fair to assume that I am exposing my algae to higher energy for photosynthesis when I use blue light?
I hope my question is understandable,
Thank you very much for the responses in advance.
If we are serious about feeding the world's growing population, and to grant food security for the next generations, we must think about boosting food production without ruining our planet.
One of the avenues being recently explored is the improvement of photosynthetic capacity by installing the C4 photosynthetic pathway into C3 crops.
By increasing the photosynthetic capacity, crops with an enhanced photosynthetic mechanism would better utilize the solar radiation that can be translated into yield.
I want to know how can we insert a C4 photosynthetic pathway into C3 ? And what are the disadvantages of this technique !?
Hello, I hope somebody could help in clarifying this point.
I am following an experiment on young olive plants in southern Italy, and I will take chlorophyll fluorescence measurements using a Fluorpen (PSI).
I will use the OJIP protocol and I am in the process of setting the saturating light intensity: I understand that in order to obtain proper Fmax measurements in dark adapted samples, one should make sure that the intensity of the initial flash of high intensity light is strong enough to temporarily close all Reaction Centers.
My questions is: which is the procedure to find the saturating light intensity ?
I already performed a series of OJIP measurements setting the light intensity from 300 to 3000 micromoles of PAR but it is not clear for me which value I should choose.
According to the Fluorpen instruction manual, one should choose the light intensity which results in the maximum Fv/Fmax ratio.
In my case this occurs at 1200 micromoles of PAR, while this ratio decreases at higher sat pulse intensities.
I also found a different suggestion in a recent review by M. Tsimilli-Michael (Revisiting JIP-test, Photosynthetic 57, 90.107, 2019): to test different light intensities (I) and to select the value for which Fpeak/I gets saturated. In my case this ratio reaches a peak at 1200 micro moles of PAR after which it starts decreasing, but I cannot see it reaching a steady value.
Am I following the right procedure ? Actually, I am not sure that 1200 micro moles could actually be a strong enough light to close all RCs in olive plants, since the “midday" PAR intensity can be over 2000 in this season.
I am looking forward to reading your comments.
I have an experiment in which I want to estimate the photosynthetic activity and carbon dioxide flux of wheat plant. However, in my institute does not have potable photosynthesis equipment. Is there any institute in Northern India from where I can hire this device on a payment basis. The device will be needed on a thirty days interval for six months. Is there any institutes which provide this facility?
Will the plant become poisonous when increased in reception of cosmic rays?
The plant's food is converted into photosynthesis
Through this process, excess radiation is received, which intends to convert it into toxic substances
These substances affect a person if he consumes the plant and results in cancers and other diseases
The affected areas are the mountainous and northern regions
I am interested in locating nutrients important for photosynthesis. How can I locate them in lemongrass leaf using SEM or some other protocol.
I am interested in locating nutrients important for photosynthesis. How can I locate them in lemongrass leaf using SEM or some other protocol.
Wish to know the detail working of a plant photosynthesis meter (infrared gas analyser) with special reference to
1. Controls that are used for analysis
2. Time of Measurements of photosynthesis i.e. before placing the leaf and after placing the leaf (stability check)
3. Analysis of the data obtained.
Request for these with special reference to the IRGA CIRAS3.
What are the current advances in techniques of remote sensing for either photosynthesis or gas exchange evaluations? What are the most promising systems? Any relevant aspect that differentiates the methods applied for a local and global scale will be very welcome.
I have been googling quite a bit but without much success but I would say someone had to have the same problem before. What I am doing is pretty much proteome-wide (translated CDS) alignments of >60 species, many of them non-model ones, to identify changes in coding regions possibly related to different photosynthesis strategies. Of course I have a list of "favourite" genes the, alignments of whic I can check manually. But I want to compare in a more non-target way to hopefully find some new genes we have not been considering as relevant so far. How can I proceed to identify such cases, e.g. new domains or amino acid substitutions occurring in a subset of species in a mremore automated way?
Is there a tool doing exactly that? Or a way to achieve this with a script (in the best case with R)?
Thank you for your suggestions.
I will be cryo-fixing a variety of plant species (woody eudicots) for ultrastructure studies via transmission electron microscopy. Previously, I have used standard chemical fixation techniques, which have not provided optimal morphology preservation. Given that cryo-fixation may be better suited for preservation and eliminating artifacts, I am interested in maximizing leaf sucrose content (sucrose serves as a cryo-protectant) in order to minimize crystal formation.
In the past, my lab has left plants in our dark room overnight (16 hours) to allow for starch degradation. My thought is that degradation of starch for chemical fixation is ideal, as starch decreases fixation penetration efficiency and time. In the context of cryo-fixing, I would guess that maximizing starch content is ideal as this will allow for faster freezing.
Any thoughts or suggestions on minimizing artifacts with cryo-fixing plant tissues would be greatly appreciated!
Main aim is to make Egyptian rice consume less water as it is a plant that requires to be flooded in water in order for the C3 photosynthesis to start. This proposal is for college and it aims to solve the water scarcity problem in Egypt and its effect on agriculture and limiting the water demanding crops such as Rice. Feel free to provide me with any thoughts, advice, sources, or genome editing tools.
Using a Horiba FluoroMax - just getting going on this procedure for the first time and can't find any explicitly clear literature online.
Some statements in Literature (Jennings et al., 2005; 2006; 2007) suggest the possibility that the second law of thermodynamics might stand in contradiction to the primary photochemistry of plants. Such an opinion seems to be rather challenging, if not to say wrong.
The necessary rise of the overall entropy when a plant grows is correlated with dissipation of energy into the environment. If a system absorbs photons and then relaxes to a final state emitting more photons than previously absorbed (in particular the production of phonons or any bosons fullfills the necessary increase of entropy) then the final state can be of lower entropy than the initial state in full accordance to the second law of thermodynamics because the environment has taken up entropy. I am currently searching for a quantitative analysis of this problem.I know (Lavergne, 2006) however the final discussion does not seem to be completely finished.
Jennings R.C., Engelmann E., Garlaschi F., Casazza A.P., Zucchelli G. Photosynthesis and negative entropy production, Biochim. Biophys. Acta, 2005, Vol. 1709, p. 251.
Jennings R.C., Casazza A.P., Belgio E., Garlaschi F.M., Zucchelli G. Reply to commentary on: Photosynthesis and negative entropy production, Biochim. Biophys. Acta, 2006, Vol. 1757, p. 1460.
Jennings R.C., Belgio E., Casazza A.P.,Garlaschi F.M., Zucchelli G. Entropy consumption in primary photosynthesis, Biochim. Biophys. Acta, 2007, Vol. 1767, p. 1194 Lavergne J. Commentary on: Photosynthesis and negative entropy production by Jennings and coworkers, Biochim. Biophys. Acta, 2006, Vol. 1757, p. 1453.
I am looking for a list of plants that utilize CAM photosynthesis. I have been searching but seems like I am missing something, anyone came across this? perhaps a document?
I am using FluorPen FP 100 (PSI, CZ) for measuring OJIP transients of various Panicum antidotale grass accession collected from various locations to assess their potential for drought tolerance. Of various JIP-test parameters, computed parameters are Phi_Pav, Pi_Abs. I assume that these two parameters are related with performance index. However, on our manuscript the reviewer commented that you have to take measurements two times for the calculations of performance index which is most suitable.
In several research papers including review articles, it has been mentioned that under non-stressed or optimum growth conditions, the Fv/Fm of PSII should be in the range of 0.81-0.83 and stress conditions might reduce the value. However, elevated [CO2] generally stimulates photosynthesis and growth of C3 plants when nitrogen supply is not limited and air temperature is within the optimum range for growth. Can Fv/Fm also increase beyond 0.83 in that case (High CO2 & N under optimum temperature) especially when taken early in the morning (8 - 11 am) after 20 min dark-adaption?
I need structural differences as well as functional differences for the three types of photosynthetic plants and how they carry out photosynthesis
The increase in plant biomass during feeding depends on the intensity of chlorophyll photosynthesis, and the NDVI is too coarse for this index - it poorly follows the high chlorophyll content and gives “duplicate” -identical values for different spectra (15-26% on wheat crops)
What alternative NDVI more accurate indices (photosynthesis rate-chlorophyll concentration) were found?
I am meeting a problem of measuring light response curve with Licor LI-6400XT. When everything is ready, the leaf temperature (Tleaf) displayed in LPL screen goes up to around 70℃ as the lamp (LED source) is turned on, but will go down to room temperature (around 20℃) as the lamp is turned off. The Tblock and Tair remain at room temperature no matter the lamp is turned on or off. Has anyone of you met the similar problem or had any possible solutions?
Thank you in advance.
Troposphere sphere contains 99℅ (by weight) of the total atmosphere. CO2 is water soluble and continuously washed during rain. Some CO2 is also get dissolved in surface water. A big percentage is trapped during photosynthesis. Still we blamed CO2 for global warming and climate change?
I read in a book Environmental Chemistry that" in anoxic region of water bodies , some bacteria use sulfate ion as an electron receptor where as other bacteria reduce iron(III) to iron (II). These two products react to give a black later of iron (II) sulfide sediment. This frequently occurs during winter, alternating with production of calcium carbonate by product from photosynthesis during the summer. "
Can anyone help me understand why this phenomena occurs during summer and winter??
Several studies on the mechanisms of acclimation in C3, C4 and CAM plants to global changes such as temperature and CO2 level fluctuations are extensively discussed. There is no distinct separation on the reported effects between the three pathways due to the involvement of many factors when studying climate change and the distribution of species in biomes of varied climate patterns; lack of data and understanding of the concepts in climate change is often cited by researchers. Though if we were to generalize a specific pathway of photosynthesis as being the most positively associated with climate change, which pathway should be considered?
I want to measure photosynthesis rate of a wheat ear by IRGA. Which is the most suitable chamber for it? Since its 3 dimensional, how will the area of ear be taken care of
I grew Podocarpus seedlings at elevated temperatures for 16 weeks after which I ran temperature response curves using a Licor 6400 IRGA.
The optimum temperature for photosynthesis remained roughly the same for heat acclimated and none-heat acclimated plants, however, max photosynthesis decreased in the heat acclimated plants. The graph is attached!
Does anyone have an explanation for this?
I've run multiple RLC's (6 reps for each of; 3 seagrass species, 5 time periods and 6 treatments). I'm am looking for a R script that can pull out the slope, ETRmax and saturating irradiance parameters.
Thank you for your help.
In general nature Escherichia coli bacteria does not contain any gene which can perform photosynthesis. whether it can develop the capability of photosynthesis after the artificial addition of photosynthesis gene from the plants to the bacteria.
Do you think using colorimetric methods to investigate the type of photosynthetic mechanism might be appropriate?
What methods do you recommend other than Spectrophotometry and HPLC methods? I would like to know your suggestions.
Is it growth parameters & biomass yield, photosynthetic pigments, nutrients, compatible solutes, photosynthesis, enzyme activities,ultrastructure?
What is the key mechanisms of biostimulant and also calcium application on stomatal conductance and photosynthesis of plants under water stress condition?
Using a chlorophyll fluorometer (Mini-PAM; Walz; Effeltrich, Germany) I plotted ETR vs PPFD curves. What software / r package/excel sheet can I used to fit this data to a rectangular hyperbola model or other models.
Most literature focuses on fitting gas exchange data, not fluorescence.
Can the same models/excel sheets as created in Lobo et al. 2013 (Fitting net photosynthetic light-response curves with Microsoft Excel - a critical look at the models work?)
Suggestions are welcomed!
It is difficult to work on crops and chances of successful experiments are very less, that is why we prefer these model organisms to study the mechanism and then apply the same knowledge on other crops. So, according to you, for different traits and developmental studies which is better?
I am trying to use paraquat (methyl viologen) to test a hypothesis related to my research on chlorophyll fluorescence. Most of the literature on paraquat that I've seen (at least to study photosynthesis) uses thylakoid suspensions. I'm not having much luck using it on whole diatom cells and I was wondering if anyone had any advice.
In immobilized algae beads, nutrients such as NH4 and PO4 get adsorbed by the immobilizing matrix (such as alginate), following which they are assimilated by the microalgae via process of photosynthesis. In most research studies, the removal of nutrients by immobilized algae beads is much higher than blank beads. So is the assimilation process faster than the adsorption process?
The figure cannot be 8 ot 9 like in oxygenic photosynthesis because NADPH2 is made by reverse electron flow in RC-2 type PS Bacteria.
Any help would be appreciated.
I am trying to measure photosynthesis of citrus (grapefruit) using Licor 6400XT. The problem is I am getting negative values. I tried with several other plants including weeds but I am not getting a positive result. I performed all the task like warming up, however, the reading is still negative. Please advice...
We're looking in addition to LICOR, and Delta-T leaf area bench meters for other options, which can be made/distributed within American or European continent (Restricted due to shipping and handling fees).
I am looking for scientific data concerning alterations in chlorophyll content, Chla/b and Chl/Car. How fast such changes can be in nature? Can they occur in hours, minutes?
I am relatively a newcomer to the amazing fields of photophysics and photochemistry.
From the available scientific literature, we may read that induced chlorophyll a fluorescence is mainly emitted by chlorophyll a molecules, located in Photosystem II (PSII), upon illumination onset. It has been reported about 300-500 chlorophyll a molecules in a single Photosystem II.
PSI fluorescence is constant and much lower than fluorescence from PSII. Its contribution to emitted plant fluorescence is considered negligible.
Some authors speak about P680 (a pigment named P680, located in Photosystem II), the reaction center RC or the special pair or the special chlorophyll dimers pigments PD1 or PD2, as the only source of fluorescence. I have a bit of confusion because it is not clear what chemical species is emitting the fluorescence that we can sense with our portable fluorometers.
1) If the Special Pair or RC is closed (it has been chemically switched to its reduced state), during the time that the Special pair is in that state, is the full bunch of chlorophyll a molecules in PSII going to dissipate their excitonic energy as fluorescence?
2) Why fluorescence emitted from PSI is not variable but constant? Does it has this fact something to do with the ratio [Chl a] to [Chl b] ???
Thank you so much in advance for your precious and kind help!
The presence of free radicals in photosynthetic and respiratory systems is inevitable, even in optimal condition for growth.
In these conditions, How much free radicals can be loss in yield?
Genetic methods to screen for mutations in plant genes, enable genes and function to be identified. High-throughput screens are needed to be able to identify low frequency mutations. Since photosynthesis has many genes and pathways, what are the components of photosynthesis that are most amendable to identify mutants using different screens?
Indoor plants that are known to survive in low light environments and also improve indoor air quality by removing some of the indoor air pollutants. Most plants perform photosynthesis and release oxygen during the day and during the night release CO2 during the respiration process.
1. Does the same scenario occur in indoor plants?
2. If so, what amount of oxygen is released during the day and the CO2 emitted during the night from the particular leaf area?
2a. Is there any ration between oxygen and carbon-di-oxide release?
2b. If so, the ratio is same for indoor and outdoor plants?
3. If not and then the houseplants also release O2 overnight. So, what is the mechanism behind this?
Apparently it is already possible to produce in laboratory conditions photochemical systems capable of conducting processes of artificial photosynthesis?
Will the construction of photochemical systems capable of conducting processes of artificial photosynthesis reduce in the future the excessive emission of greenhouse gases and protect the Earth, natural ecosystems and humans against the growing cry of accelerating the global warning process and the potential negative effects of increasingly frequent climatic cataclysms?
Will man manage to build photochemical systems capable of conducting artificial photosynthesis processes on an industrial scale to buffer the negative effects of increasing greenhouse gas emissions and inhibit the global warming process?
Carbon fixation is the conversion process of inorganic carbon (carbon dioxide) to organic compounds by living organisms. The most prominent example is photosynthesis, although chemosynthesis is another form of carbon fixation that can take place in the absence of sunlight. Organisms that grow by fixing carbon are called autotrophs. Autotrophs include photoautotrophs, which synthesize organic compounds using the energy of sunlight, and lithoautotrophs, which synthesize organic compounds using the energy of inorganic oxidation. Heterotrophs are organisms that grow using the carbon fixed by autotrophs. The organic compounds are used by heterotrophs to produce energy and to build body structures. "Fixed carbon", "reduced carbon", and "organic carbon" are equivalent terms for various organic compounds