Hot answers tagged photosynthesis
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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 ...
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There are 5 answers, all "yes".
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 addition to burglarizing the genes needed ...
8
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 ...
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If you mean the efficiency at which plants convert light energy to chemical energy (in sugar or other reduced C compounds) then there is definitely variability between plants, both at the species and individual level. The photosynthetic efficiency WP page gives ranges of between 0.1 and 8% of total solar radiation converted to "biomass", but these values are ...
6
According to wikipedia, plants typically convert around 5% of the energy of the sunlight that hit the leaves into energy usable by the plant. Sugarcane seems to be the best, it converts up to 8% of the energy into actual biomass.
The best solar panels on the market, according to the Independent, convert 21% of energy from sunlight into usable electricity. ...
5
This is not my field by a long shot, so take what I say with a grain of salt. However, this question is very hard to answer because whether or not a plant will grow depends on a great variety of factors. Even if we ignore the temperature as you say, there are other considerations. These include, but are not limited to:
Soil composition, I doubt that ...
5
Shigeta submitted his answer as I was writing this!
Sanseveria is one of a wide group of plants (mainly succulents) that adopt a photosynthetic strategy referred to as crassulacean acid metabolism (CAM).
Recall the basics of photosynthesis. The light-dependent reactions use energy from captured photons to generate ATP and NADPH, with the generation of O2. ...
5
It matters a lot.
Take a look at this graph:
This graph is for the "normal" plants containing chlorophyll.
There're also "abnormal" :-) ones, simple water plants and cyanobacteria, that contain various phycobilins for photosynthesis instead of the chlorophyll.
If your question is practical, I'd recommend using specialy-designed fluorescent lamps called ...
4
Your latter assumption is the best we have so far, to my understanding.
Here are a few excerpts from "Early Evolution of Photosynthesis" published in Plant Physiology, October 2010 (emphasis mine):
There is suggestive evidence that photosynthetic organisms were present approximately 3.2 to 3.5 billion years ago...
Overwhelming evidence indicates ...
4
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 (CO2)CH2CH(OH)(CO2) 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 ...
4
Yes and no. Yes as in the energetics do work out and you will be going down a small but non-trivial driving force as long as you continue to provide the luciferin to the algae.
However, the wavelengths of light by which photosynthesis absorbs its energy are well defined and narrow. As a result, light sources for photosynthetic organisms have to be fairly ...
3
I'm not sure that all phytoplankton perform the same type of photosynthesis.
Originally, people thought that they all performed C4, on the basis of genome sequencing, which revealed the presence of genes important for C4 photosynthesis. However, experiments on individual species seemed to indicate that the phytoplankton were performing multiple types of ...
3
This shows the major biological transformations of carbon in any system (not just lakes).
On the Left Side:
$GPP$ (Gross Primary Production) is the total amount of $C$ from atmospheric $CO_2$† that is reduced into organic molecules during the calvin cycle of photosynthesis. This is the process performed by photosynthetic organisms like green ...
3
The protein in question from Arabidopsis has this UniProt entry. In the comments you read: The N-terminus of the protein extends into the stroma where it is involved with adhesion of granal membranes and post-translational modifications; both are believed to mediate the distribution of excitation energy between photosystems I and II. As known PTMs we have ...
3
I think I found a reference. Most of these papers are behind paywalls - its a pretty obscure topic in biology, though not because it isn't interesting...
For those not familiar with the question, the thylakoid membranes are an organelle structure in the chloroplast, which contains all the photosynthetic machinery in the plant cell. The chloroplast is ...
3
Both are measures of carbon fixation rate.
RuBisCO activity specifically refers to the rate at which the enzyme RuBisCO fixes carbon to RuBP, and is measured by isolating the enzyme from tissue samples and, usually, using radiolabelled CO2 to measure how much carbon is fixed in a set amount of time in controlled conditions and with controlled supply of ...
2
One way to do this is to use the "humid operative temperature" equation, or something similar. A variant of this equation, specifically for estimating leaf temperature, is derived using a leaf energy balance equation in chapter 14.1 of the Environmental Biophysics book (cited below).
I'll let you look up the actual equation since I'm not sure how to do ...
1
In wiki there is a good answer for your question http://en.wikipedia.org/wiki/Cactus#Leaves
In plants photosynthesis takes place in chloroplasts. Chloroplasts may be in the cells of fruits, stems, but most of all in leaves. In some succulents (such as cacti), the main photosynthetic activity is associated with a stem.
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The rate of photosynthesis varies from plant to plant. Some plants require more light and some require less. If you move light closer to the plant, in most scenarios the rate of photosynthesis is likely to be increased. For some plants a minimal light is enough for their photosynthesis, so for those plants, moving light source closer or further will have ...
1
Well, according to the endosymbiosis theory both mitochondria and chloroplasts derive from ancestral bacteria that invaded/were phagocytosed (fancy word for eaten) by eukaryotic cells.
So, the electron transport chains of both mitochondria and chloroplasts would indeed share a common bacterial ancestor.
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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 ...
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