The process by which light energy is harnessed to assemble organic compounds (esp. glucose) from inorganic carbon dioxide.
1
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0answers
13 views
Where does NADP+ come from?
Trying to understand Photosynthesis better. I understand the NADP+ is reduced to NADPH in light dependent reactions and NADPH is then recycled back into NADP+ in the Calvin cycle. What I don't ...
-4
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0answers
15 views
WHAT HAPPENS AFTER PGAL HAS BEEN FORMED?
after, PGAL is formed, how does form glucose phosphate, and how does that glucose phosphate form glucose
6
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1answer
46 views
Does an old growth forest ecosystem produce more oxygen than it consumes?
I would like to consider an old growth forest ecosystem such as a large part of the Amazonian forest. It is common to refer to such beautiful forests as a source of oxygen for the world. For example, ...
0
votes
0answers
22 views
Which colour is absorbed by photosynthetic pigments?
In the process of photosynthesis, which colour is maximally absorbed by chlorophyll a?
For which colour rate of photosynthesis is maximum?
For which colour rate of absorption is maximum?
Which ...
1
vote
1answer
26 views
What values to be taken for x-axis and y-axis?
I did a lab on form and function in photosynthesis and I recorded the values of absorption spectrum in spinach chlorophyll extract. I have the following data and I need to draw a graph. I didn't ...
1
vote
0answers
30 views
Could higher carbon dioxide levels be beneficial to plants?
C4 plants take ATP-expensive routes to ensure photorespiration does not occur.
They minimise oxygen concentration in cells where the Krebs cycle occurs and cart carbon dioxide into these same cells. ...
0
votes
1answer
31 views
Does the sun light have to have *direct access* to fruits to make them sweet?
I understand that sun light is needed for fruits to ripen. In the years with less sun light, the fruits are usually not so sweet. So the sun light is needed to make the fruits sweet.
Where and how ...
1
vote
1answer
35 views
Is the rate of photosynthesis higher than the rate of respiration?
In photosynthesis carbon dioxide is used up and oxygen is produced and at the same time plants respire too. So oxygen is used up and carbon dioxide is produced.
Then the net exchange of gases should ...
3
votes
1answer
66 views
From where does the oxygen in glucose come in photosynthesis?
Is it carbon dioxide or water? I'm talking about the oxygen present in glucose and not the oxygen that is released after photolysis of water.
11
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1answer
116 views
Do fallen leaves produce oxygen?
After a leaf has fallen from a tree, if it is still green and hasn't dried out, is it still converting CO2 into O2 if not put in water?
Can anyone find any data showing how long any different ...
0
votes
1answer
19 views
Can plants yield two more molecules of ATP from glycolysis?
Since 2 ATP are used to convert glucose to glyceraldehyde 3-phosphate in glycolysis, can plants bypass this step of ATP investment since they produce glyceraldehyde 3-phosphate directly from the ...
6
votes
1answer
52 views
Why are C4 plants mainly tropical plants?
Why is it that most C4 plants are tropical plants?
As far as I am aware the C4 cycle does not prevent water loss; so having it exist in tropical areas does not serve these plants any good other than ...
4
votes
1answer
49 views
If all animals were to die, would all plants die too?
Humans and many other animals are able to breathe because plants produce more oxygen than they need. I was thinking if all animals died all of a sudden, then wouldn't plants die too. Eventually they ...
1
vote
0answers
36 views
The effect of Atrazine on the LDR in Photosynthesis
The herbicide Atrazine causes inhibition within the Qb site in the D1 protein of photosystem 2. Given this information, would Atrazine’s inhibitory effect halt the production of oxygen or ATP first?
...
4
votes
0answers
54 views
Recent research in bioluminescence powering photosynthesis?
In 2013 there was a Chinese study published on "Bioluminescence as a light source for photosynthesis," which is briefly summarized in this Chemistry World article. There was a question on Biology.SE ...
0
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0answers
26 views
Photosynthesis Experiment - unexpected temperature results
So for Stage 2 Biology we had to do a photosynthesis practical where we manipulate one variable.
Summary of prac method:
- 50 geranium plant leaf discs were cut using a hole puncher and placed into ...
2
votes
0answers
111 views
How many photons are used to make one glucose?
This was a question in a test. The options were
(1) 8
(2) 16
(3) 24
(4) 48
My answer is 30 which was not in options. Given answer was 48.
12 NADPH
18 ATP for one glucose
12 NADPH and ATP ...
1
vote
0answers
58 views
Could alternatives to Photosynthesis be possible? [closed]
I'm working on a world for stories and games, and I'm trying to figure out some more diverse plantlife. There are areas of the world that won't get enough sunlight for Photosynthesis, so I'm thinking ...
3
votes
0answers
49 views
Does blue light cause stomata to open or close?
In my biology lecture notes, it says that blue light causes stomata to close.
But thinking about it logically, since plants absorb a high percentage of blue light compared to light at other ...
0
votes
0answers
58 views
c4 cycle in photosynthesis occurs in monocots or dicots
the biosynthetic portion of the c4 cycle occurs in the bundle sheath cells and i have studies that bundle sheath cells are present only in dicots and not monocots.
according to this, the c4 cycle ...
29
votes
3answers
4k views
Can plants suffer from CO2 poisoning?
Is there a point where too much CO2 is bad for a plant? Basically when there is too much CO2 in the air can a plant get sick?
Since plants photosynthesize and need CO2 to generate glucose and store ...
0
votes
1answer
27 views
Oxygen balence from growing plants for food
I had thought photosynthesis and respiration where pretty much Oxygen and Carbon neutral per calorie.
http://news.mit.edu/2014/technical-feasibility-mars-one-1014
If, as the project plans, crops ...
3
votes
0answers
26 views
Effect of the Marcus Theory on Photosynthesis
As far as I know, the Marcus Theory explains the rates of electron transfers in reactions as a function of differences in free energy between the product/reactant's potential well.
Furthermore, there ...
-1
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1answer
36 views
Effect of light spectrum on photosynthesis
It is said that the blue and red fraction of VIBGYOR is mainly used for photosynthesis. Can somebody explain why this is so?
2
votes
1answer
542 views
Purpose of the conversion of 3-PGA to G3P in the calvin cycle?
3-PGA ($\ce{C_6H_7O_7P}$) is converted to G3P ($\ce{C_6H_7O_6P}$) before it is able to be made into glucose, with an expansion of 6 ATP and 6 NADPH. My question is why this process is needed and why ...
3
votes
0answers
49 views
What amount of light energy is required to produce one O2 molecule? How about one molecule of NADPH?
I know that for each O2 molecule, a total of 8 photons are required (4 per photosystem). Would the amount of light energy required be E=hc/wavelength using 680 and 700? Or would the energy from the ...
2
votes
0answers
46 views
At what point in the day do plants start to absorb light for photosynthesis?
My plants sit on a small table in my only window, facing Northwest. They are thriving. They are obviously getting enough indirect light to survive year round. Maybe they have adapted? They have never ...
1
vote
1answer
83 views
As electrons are moving through the ETC, how is ATP produced for the active transport to even happen?
A lot of websites aren't being specific and they are just saying that when electrons move from a high to low energy state during the ETC, "energy" is being released and that energy is used to pump (...
1
vote
1answer
256 views
During non-cyclic photophosphorylation, how does NADP+ become NADPH?
I know that NADP+ gets reduced to form NADPH, but what exactly is being donated? Is it two individual electrons (from photolysis or the chlorophyll molecules) and a hydrogen ion (proton)? If this is ...
3
votes
0answers
52 views
Can plants photosynthesize all-day?
If a plant was given sunlight even during the night, with appropriate constant intensity during day and night, will the plant be able to maintain health and normally photosynthesize throughout the day?...
1
vote
0answers
45 views
Can combining C3, C4 and CAM plants in a greenhouse/vertical farm increase the efficiency of plant production?
I am reading a little about different types of photosynthetic systems in plants because I want to learn something about plant production in greenhouses/vertical farms (I have no experience in this ...
1
vote
0answers
61 views
Import of H+ ions into the thylakoid space during photosynthesis in plants [closed]
Why are H+ ions pumped into the thylakoid space as the electrons pass through the cytochrome complex from PS2 to PS1 during photosynthesis?
1
vote
2answers
184 views
Intermediate of Krebs cycle that can form Chlorophyll?
This was a question in a test in my school today.
Q) Which intermediate of Krebs cycle further can form chlorophyll?
A) Oxaloacetic acid
B) Citric acid
C) Succinyl CoA
D) Fumarate
Given answer was ...
0
votes
2answers
218 views
Potato Power. Self sustaining medium using a living potato plant possible?
The second picture are potatoes wired in parallel. I understand that the potato is the medium for a chemical reaction between the copper and zinc.
That aside, would wired and in soil potato plant ...
0
votes
0answers
15 views
UV pigmentation for photosynthesis
Are there any known molecules that are used by plants to absorb UV light for the purposes of photosynthesis? I know that UV is typically damaging for plants, but it is used in many industrial organic ...
3
votes
1answer
334 views
Chloroplasts in an animal cell
What would happen if we inject a chloroplast organelle into an animal cell?
Will the animal cell destroy it? Or is it possible that the chloroplast will somehow survive, and even replicate? Could ...
4
votes
1answer
84 views
Cyanobacteria pools as carbon sinks
According to some scientists, at one point in time in this planet's history cyanobacteria almost drove life to extinction by reducing it to a snowball as they captured vast quantities of carbon and ...
0
votes
0answers
9 views
Energy transfer to reaction centre in higher plants
In a photosystem, the accessory pigment molecules in the LHC(light harvesting complex) absorb the quanta from different regions of PAR(photosynthetically active radiation) , their electron gets ...
2
votes
0answers
24 views
Mobile carriers of Light reaction in higher plants
The hydrogen carrier PQ and the electron carrier PC are the mobile carriers in light reaction facilitating electron transfer from PS II to PS I during non-cyclic process.
My question is -
How do ...
1
vote
2answers
46 views
Reaction centre in Photosystems of higher plants
In photosystems of higher plants, there are about 250-400 pigments (number wise) in a particular photosystem. Out of which,approx 170-180 pigments are of chlorophyll a molecules. And any one of them ...
2
votes
0answers
53 views
Are there special pairs present in the RC of both photosystem I and photosystem II?
I am confused regarding the existence of special pair (primarily regarding PS2). Do both, P680 and P700 have special pair?
I have checked various sources online and have come across conflicting ...
0
votes
0answers
40 views
Where Does Radioactive Carbon End Up?
If 3 radioactive carbon-14 were added to calvin cycle as CO2, after one turn of the cycle, what molecules of the calvin cycle are expected to be radioactive?
All the diagrams of the calvin cycle ...
0
votes
0answers
41 views
How does photosynthesis affect algae growth?
I'm doing a biology project and I cannot find any good sources to explain how increasing photosynthesis will increase the potential yield of alage. I will increase light intensity for (C.vulgaris). I ...
0
votes
0answers
33 views
Optimal average plant absorption maxima/peaks of chlorophyll and photosensitive pigments?
I'm finding alot of different results. I've seen results from leaf gas exchange,chlorophyll fluorimetry, and spectrophotometry ,but I'm looking for in vivo and in situ results from leaf absorption.
I ...
2
votes
2answers
1k views
How is Glyceraldehyde 3-phosphate converted into glucose?
In the light-independent reaction of photosynthesis, one of the products is glyceraldehyde 3-phosphate, and the Wikipedia page on the light-independent reactions states that 6 of these can be used to ...
3
votes
1answer
151 views
What can we infer from Warburg's Flashing Light experiment?
The 'Dark Phase' in photosynthesis as I know is not dependent on darkness, but is just 'Light Independent'. But the Warburg Flashing light experiment, makes me think again. Warburg obtained higher ...
0
votes
2answers
33 views
How can rhodobacter possess a single 'PS-II' like reaction center?
I recently came across an information in my book Trueman's Elementary Biology , a popular text in India, that photosynthetic bacteria like Rhodobacter, Rhodopseudomonas etc. possess a single ...
0
votes
0answers
51 views
Photorespiration prevents plant from photo oxidative damage?
Can photorespiration protect plant from photo oxidative damage be dissipating excess of excitation energy?
This was a question in a test and the answer was yes. But according to me, photorespiration ...
1
vote
0answers
18 views
Can Phosphogycolate buildup in a plant kill it?
I'm trying to think of some things for the science fair, for part of my experiment I need to know if Phosphogycolate build up in a plant can kill it. Also, are there any chemicals that may disrupt the ...
8
votes
2answers
1k views
Is it considered feasible to genetically improve plants for better Carbon dioxide breakdown?
I have found several somewhat related questions and answers here and elsewhere, but I couldn't find, if any scientist groups are researching genetical improvement possibilities of existing plants' ...
