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Questions tagged [chloroplasts]

The organelle in which photosynthesis occurs

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1answer
27 views

Do all cells of a plant contain chloroplasts? [closed]

If the answer is no, then how do plant cells tell whether they need to keep chloroplasts or not? What kind of signals are used, and how are chloroplasts eliminated?
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22 views

Recombination between organelles?

In plants, organelles DNA inside chloroplasts and mitochondrias can undergo recombination, intra- or inter-molecular. In a single cell, there are numerous chloroplasts/mitochondria. Can we imagine ...
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1answer
162 views

Why do proteins targeted for chloroplasts require two signal peptides?

Question #11 of the GRE Biology Practice Test says that proteins targeted for chloroplasts require two signal peptides: Targeting of a newly synthesized protein is most likely to require two ...
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0answers
42 views

What happens when pure chlorophyll A absorbs blue light?

When pure chlorophyll A is put in the presence of only blue light, what happens? My guess is that the extra energy is released as heat/kinetic energy, and then the electron has dropped to the lowest ...
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1answer
108 views

What plants use the green spectrum? [closed]

What if the only light provided to a plant was from the green spectrum would plants adapt or starve?
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1answer
619 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 ...
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0answers
50 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 ...
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2answers
72 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 ...
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1answer
149 views

Which cell organelle is more important in giving colour to petals? [closed]

It was a question in our school test and given answer was vacuole. But I think it should be chromoplast as they are the organelles specialised to provide colour. But options were given, so which is ...
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231 views

How long can algae survive with no air recycling (closed bottle)

In a small bottle nearly filled of Chlorella in water and grow medium, how long would it take for them to die (with or without light). Thanks in advance ;)
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2answers
642 views

What is this green micro-organism found living in water?

I study biology in France and experiment on water filtration with plants. I found that some chlorophyll-containing micro-organisms (about 10 micrometers in length) were raised in my basin. I can't ...
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3answers
6k views

Photosystem 1 and 2; P680/P700; Chlorophyll a/b

I am getting slightly confused about how the above relate to each other. My current understanding is that P680 and P700 refer to the primary pigment reaction centres in Photosystems 2 and 1 ...
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0answers
40 views

Enhanced Spectrum Chloroplasts

As far as I'm aware, chloroplasts produce energy through the use of photosynthesis which essentiall converts CO2 and Water into Glucose (I'm an engineer by trade so really wracking my brains to the ...
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0answers
1k views

Difference in ATP synthesis in mitochondria and chloroplast

The mechanism of ATP synthesis in mitochondria and chloroplasts are almost the same, but there is a big difference: the f1 particle in mitochondria uses 2 H+ ions to synthesize one ATP, whereas in ...
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0answers
30 views

Mg in bacteriochlorophyll

In the figure 1A of http://photobiology.info/Jones.html the Mg is not belong to other structure. Is that because something is omitted or is it indeed like a pearl in a mussel's mouth? In the later ...
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2answers
473 views

Do Gametes contain mitochondria/chloroplasts from their parent cell?

It has now been established (according to the Cambridge A level text book) that organisms form a symbiotic partnership, typically by one engulfing the other – a process known as endosymbiosis. ...
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1answer
310 views

Evolution of plants and chloroplasts?

I am considering the evolution of plants, specifically considering the chloroplast. I am getting slightly confused and cannot seem to find the information I need to build a coherent picture in my head....
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0answers
83 views

Is lumen space of a thylakoid completely separate from the intermembrane chloroplast space?

The question I have is whether thylakoids form actually completely independent "vacuoles" (i.e. independent membrane enclosed spaces) or whether the lumen space is connected to the intermembrane space ...
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1answer
482 views

Plant cell question in age 12 science test

Can anyone help me answer the questions in the attachment about plant cells. It was a question in my 12 year olds science exam. I'm baffled as I think he has given a good knowledgable answer but it ...
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0answers
165 views

How does an increase in CO2 concentration affect Photosynthesis and Transpiration

I noticed a strange thing in my book. At one place it says that an increase in CO$_2$ concentration in the outside air decreases the rate of transpiration but at the other place it says that an ...
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1answer
2k views

Why is chlorophyll green? Isn't there a more energetically favorable color? [duplicate]

Chlorophyll being green means it absorbs light in the red and blue area of the spectrum. Isn't this the high and low energy light? Wouldn't plants get more energy if they absorbed light in the green ...
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1answer
4k views

Origin of the double membrane of mitochondria and chloroplasts

Most websites and textbooks say that the double membrane of mitochondria and chloroplasts are a result of the endocytosis of ancient prokaryotes (the outer membrane is from the vesicle containing the ...
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0answers
868 views

Trouble understanding how uncouplers in the thylakoid membrane increase the rates of the Electron transport chain?

I am a undergrad in a cell physiology class and just did a learning exercise involving testing rates of the electron transport chain via the reduction of DCPIP, analyzed by spectrophotometry. ( I ...
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0answers
119 views

Why do chlorotic leaves have green veins?

If chlorotic leaves are chlorophyll deficient, why should the veins be green? shouldn't all the available chlorophyll be directed to the leaf lamina?
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1answer
2k views

What do the numbers in Photosystem I P700 and Photosystem II P680 stand for? Is it the optimum wavelenght? The maximum wavelenght?

I am a bit confused about this because my teacher and english Wikipedia say it's the wavelenght the Photosystem is most reactive to; my textbook and the german Wikipedia say that it is the maximum ...
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4answers
39k 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?
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0answers
39 views

Which biosynthetic pathways take place in the plastid and were are they located?

I know that the isoprenoid, jasmonate, glucosinolate, fatty acids, chlorophyll, starch, and aromatic amino acid syntheses are located in the plastid. But I don't know if they are located in the ...
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2answers
726 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 ...
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2answers
7k views

Difference between thylakoids and lamellae in a chloroplast?

I'm slightly confused as to the difference between thylakoids and lamellae. My understanding was that thylakoids are 'discs' that are stacked into grana and there is a membrane between the grana ...
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4answers
20k views

Was the mitochondrion or chloroplast first?

I still don't know if the mitochondrion or chloroplast was first? I've looked for it on the internet and in various books but haven't found anything. Does anyone have the answer and a theory which ...
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1answer
2k views

Plastid and mitochondria

I am not a biologist, so please bear with me for this basic question. Although I tried googling, I am confused. What is the difference between plastids, chloroplasts and mitochondria? Are there any ...
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1answer
180 views

Common Ancestry of ETCs and ATP Synthase complexes

Rickettsiales are widely regarded as the ancestor of eukaryotic mitochondria through endosymbiosis. Cyanobacteria are widely regarded as the ancestor of eukaryotic chloroplasts through endosymbiosis. ...
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1answer
2k views

How fast does the rotor in ATP synthase spin?

I'm sure the exact frequency varies, but does anyone know roughly how many revolutions per minute / second the rotating center part makes?
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8answers
18k views

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 ...
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4answers
3k views

How many times did endosymbiosis occur?

According to the endosymbiont theory, mitochondria and chloroplasts originated as bacteria which were engulfed by larger cells. How many times is it estimated that this occurred in the past? Are there ...