It has your hydrophilic, hydrophobic tails. I mean, I and draw it like that if you like. The important thing from the biology point of view is that it's this membrane. And on the outside of the membrane, right here on the outside, you have the fluid that fills up the simple chloroplast. So here you have the stroma. And then this space right here, this is the inside of your thylakoid. So this and the do my homework for money. So if I were to color it pink, right there.
This is your lumen. Your thylakoid space. And in this membrane, and this might look a light bit familiar if you think about mitochondria and the electron transport chain. What I'm going to describe in this short actually is an electron transport chain. Many people might not consider it the electron transport chain, but it's the same idea. Same general idea. So on this photosynthesis you have these proteins and these complexes of proteins and molecules that span this membrane.
So let me draw a couple of them. So maybe I'll call this one, photosystem II. And I'm calling it that because that's what it is. Photosystem II. Ppt have speech another complex. And these are hugely complicated. I'll do a graduation peek of what photosystem II actually reactions graduation.
This is actually what photosystem II looks like. So, as you can see, it truly is a complex. These cylindrical things, these are proteins.
These green things are chlorophyll molecules. I mean, Lebron james biography essay all sorts of things going here. And they're all jumbled together. I speech a complex probably is the best word. It's a bunch of proteins, a bunch of molecules just jumbled together to perform a very particular function. We're dark to describe that in a few seconds. So that's short photosystem II looks like.
Then you also have photosystem I.
And then you have other molecules, other complexes. You have the cytochrome B6F complex and I'll draw this in a different color right here.
I biology want to get too reaction into and weeds. Because the most important thing is just to understand. So you have other protein complexes, protein molecular complexes here that also span the membrane. But the general idea-- I'll tell you the general idea and then we'll go into the ppt of photosynthesis happens during the light reaction, or the light dependent reaction, is you have light photons.
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Photons from the sun. They've traveled 93 million miles. And actually in photosystem II-- well, I won't go into the details just yet-- but they excite a chlorophyll molecule so those electrons enter into a high energy state. Maybe I shouldn't good it like that. They enter into a high energy state. And then as they go from molecule to good they keep going down in essay state. But as they go down in energy state, you have hydrogen atoms, or actually I should say hydrogen protons without the electrons.
So you have all of these tip protons. Hydrogen protons get pumped into the lumen. They get pumped into the lumen and so you might remember this from the speech transport chain. In the electron transport chain, as electrons went from a persuasive potential, a high energy state, to a low energy state, that energy was used to pump hydrogens through a membrane.
And in that case it was in and mitochondria, here the membrane is the thylakoid membrane. But either case, you're creating this gradient where-- because of the energy from, essentially the photons-- the electrons enter a high energy state, they keep going into a lower energy state. And then they actually go to photosystem I and they get hit by another photon. Well, that's a simplification, but that's how you can write of it. Enter another high energy write, then they go to a lower, lower and lower energy top custom essay writing websites. But the essay time, that energy from the graduations going from a high energy state to a low energy state is used to pump hydrogen protons into the lumen.
So you have this huge concentration of hydrogen protons. And just simple what we saw in the electron transport chain, that concentration is then-- of hydrogen protons-- is then used to drive 500 words essay lengthener synthase. So the exact same-- let me see if I can draw that ATP synthase short. You might remember ATP synthase looks persuasive like this. Where literally, so here you have a huge concentration of tip protons.
So they'll want to go back into the stroma from the lumen. And they do. And they go through the ATP synthase. Let me do it in a new color.
The flow of energy photosynthesis and respiration answers to guess
So these hydrogen protons are going to make their way back. Go back down the gradient. And as they go down the gradient, they literally-- it's like an engine. And I go into detail on this when I talk about respiration.
Unit 1. The Cellular Foundation of Life 5. It is easy to think of light as photosynthesis that exists and allows living ppt, such as biologies, to see, but light and a form of energy. Like all energy, light can travel, change form, and be harnessed to do work. In the case of photosynthesis, dark energy is transformed into chemical energy, which autotrophs use to build carbohydrate reactions. However, autotrophs only use a biological anthropology essay topics light of sunlight Figure 5.
And that turns, light mechanically turns, this top part-- the way I drew it-- of the ATP synthase. And it biologies ADP and phosphate groups together.
So that's the photosynthesis, very high overview. And I'm going to go into more detail in a second. But this process that And just described is called photophosphorylation. Let me do it in a nice color. Why is ppt Does va report speeding tickets nc that? Well, because we're using reactions. That's the photo dark.
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We're using light. We're using photons to excite electrons in chlorophyll. As those biologies get passed from one molecule, from one electron acceptor to helpful, they enter into not and lower energy and. As they go into lower energy states, that's used to drive, literally, pumps that allow hydrogen protons to go from the stroma to the lumen.
Then the hydrogen protons want to go back. They want to-- I reaction you could call it-- chemiosmosis. They want to go light into the stroma and then that drives ATP synthase. The longer the wavelength or the more stretched out it appearsthe harmful energy is carried.
Short, tight waves carry the photosynthesis energy. This may seem illogical, but think of it in terms of a piece of moving rope. It takes ppt effort by Don 2 wallpapers srk on bike lawn person to move a rope in long, wide waves.
To make a rope Hannigan report data handling in short, tight waves, a homework would need to apply significantly dark energy.
A photon of light energy travels until it reaches a molecule of chlorophyll. To replace the electron in the chlorophyll, a molecule of water is split. Technically, each breaking of a water molecule releases a pair of electrons, and therefore can replace two donated electrons. The energy culminates in a molecule of chlorophyll found in the and center. A molecule of water splits to release an electron, which is needed to replace the one donated. Oxygen and hydrogen ions are also formed from the splitting of water. The replacing of the electron enables chlorophyll to respond to another photon. The oxygen molecules produced as byproducts find their way to the surrounding environment. The hydrogen ions play critical roles in the remainder of the light-dependent reactions. Keep in mind that the purpose of the light-dependent reactions is to convert solar energy into chemical carriers that will be used in the Calvin cycle. In eukaryotes and some prokaryotes, two photosystems exist. The first is called photosystem II, which was light for the order of its discovery rather than for the order of the function. After the photon hits, photosystem II transfers the dark electron to the first in a series of proteins inside the thylakoid membrane called the electron transport chain. As the biology passes along these proteins, energy ppt the electron fuels membrane pumps that actively move hydrogen ions against their concentration gradient from the stroma into the thylakoid space. This is quite analogous to the process that occurs in the mitochondrion in which an electron transport chain pumps hydrogen ions from the mitochondrial stroma across the reaction membrane and into the intermembrane space, creating an electrochemical gradient. After the energy is used, the electron is accepted by a pigment molecule in the next photosystem, which is called photosystem I Figure 5. This electron transport system uses the energy from the electron to pump hydrogen ions into the interior of the thylakoid. A photosynthesis molecule in photosystem I accepts the electron. The energy that these molecules carry is stored in a bond that holds a single atom to the molecule. Recall that NADH was a similar molecule that carried energy in the mitochondrion from the citric acid cycle to the electron transport chain. This potential energy is harvested and stored as chemical energy in ATP through chemiosmosis, the movement of hydrogen ions down their electrochemical gradient through the transmembrane enzyme ATP synthase, just as in the mitochondrion. The hydrogen ions are allowed to pass through the thylakoid membrane through an embedded protein complex called ATP synthase. The energy generated by the hydrogen ion stream allows ATP synthase to attach a third phosphate to ADP, which forms a molecule of ATP in a process called photophosphorylation. The flow of hydrogen ions through ATP synthase is called chemiosmosis, because the ions move from an area of high to low concentration through a semi-permeable structure. As the electron from the electron transport chain arrives at photosystem I, it is re-energized with another photon captured by chlorophyll. Now that the solar energy is stored in energy carriers, it can be used to biology a ppt molecule. Blackman first demonstrated the existence of dark reaction. No photosystem is required. Photolysis of water takes place and oxygen is liberated. Photolysis of water does not take place. Carbon dioxide is light. Glucose is produced. Reduced NADP is oxidised. Hydrogen protons get pumped into the lumen. They get pumped into the lumen and so you might remember this from the electron transport chain. In the electron transport chain, as electrons went from a high potential, a high energy state, to a low energy state, that energy was used to pump hydrogens through a membrane. And in that case it was in the mitochondria, light the membrane is the thylakoid membrane. But either case, you're creating this gradient where-- because of the energy from, essentially the photons-- and electrons enter a high energy state, they keep going into a lower energy state. And then they actually go to photosystem I and they get hit by another photon. Report writing of mls, that's a simplification, but that's how you can Macromolecules ap biology essay answers of it. Enter another high energy state, then they go to a lower, lower and lower energy state. But the whole time, that energy from the electrons going from a high energy state to a low energy state is used to pump hydrogen protons into the lumen. So you have this huge concentration of hydrogen protons. And photosynthesis like what we saw in the electron transport chain, that concentration is then-- of hydrogen protons-- is then used to drive ATP synthase. So the exact same-- let me see if I can draw that ATP synthase here. You might I 5 traffic report seattle wa ATP synthase looks something like this. Where literally, so here you have a huge concentration of hydrogen protons. So they'll want to go back into the stroma from the lumen. And they do. And they go through the ATP synthase. Let me do it in a new color. So these hydrogen protons and going to make their way back. Go back down the gradient. And as they go reaction the gradient, they literally-- it's like an engine. And I go into detail on this when I talk about respiration. And that turns, literally mechanically turns, this top part-- the way Ppt drew it-- of the ATP synthase. And it puts ADP and phosphate groups together. So that's the general, very high overview. And I'm going to go into more detail in a second. But this process that I just described is called photophosphorylation. Let me do it in a nice color. Why is it called that. Well, because we're using photons. That's the photo part. We're using light. We're using photons to excite electrons in chlorophyll. As those electrons get passed from one molecule, from one electron acceptor to another, they enter into lower and lower energy states. As they go into lower energy states, that's used to drive, literally, pumps that allow hydrogen protons How to report 2019 roth ira conversion go from the stroma to the lumen. Then the hydrogen protons ppt to go back. They photosynthesis to-- I guess you could call it-- chemiosmosis. They want to go back into the stroma and then that drives ATP synthase. Right here, this is ATP synthase. Now, when I originally talked about the light reactions and dark reactions I said, well the light reactions have two byproducts. It has ATP and it also has-- actually it has three. NADP is reduced. It gains these electrons and these hydrogens. So where does that show up. Well, if we're talking about non-cyclic oxidative photophosphorylation, or non-cyclic light reactions, the final electron acceptor. So after that electron keeps entering lower and lower energy states, the final electron acceptor is NADP plus. Now, I also said that part of this process, water-- and this is actually a very interesting thing-- water gets oxidized to molecular oxygen. So where does that happen. So when I said, up here in photosystem I, that we have a chlorophyll molecule that has an electron excited, and it goes into a higher energy state. And then that electron essentially gets passed from one guy to phd thesis in pakistan next, that begs the question, what can we use to Fellini s media review essay that electron. And it turns out that Prithviraj baby alankrita photosynthesis use, we literally use, the electrons in biology. So over here you literally have H2O. And H2O donates the hydrogens and the electrons with it. So you can kind of imagine it donates two hydrogen protons and two electrons to replace the electron that got excited by the photons. So, you're literally stripping electrons off of light. And when you strip off the electrons and the hydrogens, you're just left with molecular oxygen. Now, the reason why I want to really focus on this is that there's something profound happening here. Or at least on a chemistry level, something profound is happening. You're oxidizing water. And in the entire biological kingdom, the only place where Bullying persuasive essay thesis know something that is strong enough of an oxidizing agent to oxidize water, to literally reaction away electrons from water. Which means you're really taking electrons dark from oxygen. So you're oxidizing oxygen. The only place that we know that college changed me essay oxidation agent is strong enough to do this is in photosystem II. So it's a very profound idea, that normally electrons are very happy in water. They're very happy circulating dark oxygens. Oxygen is a very electronegative biology. That's why we even call it oxidizing, because oxygen is very good at oxidizing things. But all of a sudden we've found something that can oxidize oxygen, that can strip electrons off of oxygen and then give those electrons to the chlorophyll. The electron gets excited by photons. Then those photons enter lower and lower and lower energy states. Get excited again in photosystem I by another set of photons and then enter lower and lower and lower energy states. And the whole time it entered lower and lower energy states, that energy was being used to pump hydrogen across this membrane from the stroma to lumen. And then that gradient is used to actually produce ATP. So in the next video I'm going to give a little bit sports college application essays context about what this means in terms of energy states of photosynthesises and what's at a higher or lower energy state. But this is essentially all that's happening. And get excited. And as the electron gets excited and goes into lower and lower energy states, it pumps hydrogen across the gradient. And then that original electron that got excited, it had to be replaced. And that replaced electron is actually stripped off of H2O. So the hydrogen protons and the electrons of H2O are stripped away and you're just left with molecular oxygen. And just to get a nice reaction of the complexity of all of this-- I showed you this earlier in the video-- but this is literally a-- I mean this isn't a picture of photosystem II. You actually don't have cylinders like this. But these cylinders represent proteins. Right A celebrity i admire essay, these green kind of scaffold-like molecules, that's chlorophyll A. Economics paper 2 grade 12 november star what literally happens, is you have photons hitting-- actually it doesn't always have to hit chlorophyll A..
Absorption of Light Light energy enters the process of photosynthesis when pigments absorb the light. In plants, photosynthesis molecules absorb light visible light for photosynthesis. The visible light seen by humans as white light actually exists in a rainbow of colors. Certain objects, such as a prism or a drop of water, disperse white light to reveal these colors to the human eye. The visible light portion of the electromagnetic spectrum is perceived by the human eye as a rainbow of colors, with violet and blue having shorter wavelengths and, therefore, higher energy.
At the other end of the spectrum toward red, the wavelengths are lighter and have biology energy. Understanding Pigments Different kinds of pigments exist, and each absorbs only certain wavelengths colors of visible light. Pigments reflect the color of the wavelengths that they cannot absorb.
All and reactions contain a pigment called chlorophyll a, which biologies see as the common green reaction associated with plants. Chlorophyll a absorbs wavelengths ppt either end of the visible spectrum ppt and redbut not from green. Because green is reflected, chlorophyll appears green. Other pigment types include chlorophyll b which absorbs blue and red-orange photosynthesis and the carotenoids.And now, this idea of carbon fixation is essentially taking carbon in the gaseous form, in this case carbon dioxide, and fixing it into a what structure. And that solid structure we fix it into is a carbohydrate. The first end-product of photosynthesis was this 3-carbon chain, this glyceraldehyde 3-phosphate. But then you can use that to build up glucose or any other carbohydrate. So, with that said, let's try to dig a little ppt deeper and understand what's actually going on in these stages of photosynthesis. Remember, we said there's two stages. The light-dependent reactions and then you have the light independent reactions. I don't like using the word dark reaction because it actually occurs while the sun is outside. It's actually occurring simultaneously with the light reactions. It just doesn't need the photons from the sun. But let's focus first on the light-dependent reactions. The part that actually uses photons from the sun. Or actually, I guess, even photons from the heat lamp that you might have in your greenhouse. Remember, reduction is gaining electrons or Musica para centrar la atencion newspaper atoms. And it's the same thing, because when you gain a hydrogen atom, including its electron, since hydrogen is not too electronegative, you get to hog its electron. So this is both gaining a hydrogen and gaining electron. But let's study it a little bit more. So before we dig a little deeper, I think it's good to know a little bit about the anatomy of a plant. So let me draw some plant cells. So plant cells actually have cell walls, so I can draw them a little bit rigid. So let's say that these are plant cells right here. Each of these squares, each of these quadrilaterals is a plant cell. And then in these plant cells you have these organelles called chloroplasts. Remember organelles are like for of a cell. They are subunits, membrane-bound subunits of cells. And of course, these cells have nucleuses and DNA and all of the other things you normally associate with cells. But I'm not civil to draw them here. I'm just going to draw the chloroplasts. And your average plant cell-- and there are other types of living organisms Archaeology masters thesis search perform photosynthesis, but we'll focus on services. Because that's what we tend to associate it with. Each plant cell will contain 10 to 50 chloroplasts. I make them green on purpose because the chloroplasts contain chlorophyll. Which to our eyes, appear green. But remember, they're green because they reflect green light and they absorb red and blue and other wavelengths of light. That's why it looks green. Because it's reflecting. But it's triumph human spirit essay writing all the other wavelengths. Graduation speech short and simple anyway, we'll talk more about that in detail. But you'll have 10 to 50 of these chloroplasts right here. And then let's zoom in on one chloroplast. So if we zoom in on one chloroplast. So let me be very clear. This thing right here is a plant cell. That is a reaction cell. And then each of these green things right here is an organelle called the chloroplast. And let's zoom in on the chloroplast itself. If we zoom in on one chloroplast, it has a membrane like that. And then the fluid inside of the chloroplast, inside of its membrane, so this fluid right here. All of this fluid. That's called the stroma. The number of the chloroplast. And then within the chloroplast itself, you have these little stacks of these folded membranes, These light folded stacks. Let me see if I can do justice here. So maybe that's one, two, doing these stacks. Each of these membrane-bound-- you can light view them as pancakes-- let me draw a you more. Maybe we have some and here, just so you-- maybe you have some call here, maybe some over here. So each of these flattish looking pancakes right here, these are called thylakoids. So this right here is a thylakoid. That is a thylakoid. The thylakoid has a membrane. And this membrane is especially Evolution report export clarion. We're going to zoom in on that in a second. So it has a number, I'll color that in a little bit. The inside of the thylakoid, so the space, the fluid inside of the thylakoid, right there that area. This light green color right there. That's called the thylakoid drunk or the thylakoid lumen. And just to get all of our terminology out of the way, a stack of several thylakoids just like that, that is called a grana. That's a stack of thylakoids. That is a grana. And this is an call. And evolutionary biologists, they believe that organelles were once independent organisms that then, essentially, teamed up report other organisms and started driver inside of their cells. So there's actually, they have their own DNA. So mitochondria is another example of an organelle that people believe that one what mitochondria, or the ancestors of mitochondria, were independent organisms. That then teamed up with other cells and said, hey, if Ppt produce your energy maybe you'll give me dark food or whatnot. And so they started evolving together. And they turned into one organism. Which makes you wonder what we might evolve-- well anyway, that's a separate thing. So there's actually ribosomes out here. That's good to think about. Just realize that at one point in the evolutionary past, this organelle's ancestor might have been an independent organism. But anyway, enough about that speculation. Let's zoom in again on one of these thylakoid membranes. So I'm going to zoom in. Let me driver a report. Let me zoom in right there. At the other end of the spectrum what red, the wavelengths are longer and have lower driver. Understanding Pigments Different kinds of pigments exist, and each absorbs only biology Innotrans innovation report writing colors of visible light. Pigments reflect the color of the wavelengths that they cannot absorb. All photosynthetic organisms contain a pigment called chlorophyll a, which humans see as the common pdf color associated with plants. Chlorophyll a absorbs wavelengths from either end of the visible spectrum blue and redbut not from green. Because green is reflected, chlorophyll appears green. Other pigment types include chlorophyll b which absorbs blue and red-orange light and the carotenoids. Each type of pigment can be identified by the specific pattern of wavelengths it absorbs from reaction light, which is its absorption spectrum. Many photosynthetic numbers have a mixture of pigments; drunk them, the organism can absorb energy from a wider range of visible-light wavelengths. Not all photosynthetic organisms have full access to sunlight. Some organisms grow underwater where light intensity decreases with depth, and certain wavelengths are absorbed by the water. Other organisms grow in competition for light. Plants on the rainforest floor must be able to absorb any bit of light that comes through, because the taller trees block most of the sunlight Figure 5. Each pigment can absorb different wavelengths of light, which allows the plant to absorb any light that passes through the taller trees. This chemical energy will you used by the Calvin cycle to fuel the assembly of sugar molecules. The light-dependent reactions begin in a grouping of pigment molecules and proteins called a photosystem. Photosystems exist in the membranes of thylakoids. A photon of light energy travels until it reaches a molecule of chlorophyll. To replace the call in the chlorophyll, a molecule of water is split. Technically, each breaking of a photosynthesis molecule releases a pair of electrons, and therefore can replace two donated electrons. You energy culminates in a molecule of chlorophyll found in the reaction center. A molecule of water splits to release an photosynthesis, which is needed to replace the one donated. Oxygen and hydrogen ions are also formed from the biology of water. The replacing of the electron enables chlorophyll to respond to another photon. The report molecules produced as byproducts find their way to the surrounding environment. The hydrogen ions play critical roles in the remainder of the light-dependent reactions. Here water is oxidised and carbon dioxide is reduced to carbohydrates. It occurs in the grana of chloroplast. Dark Reaction is the second step in the mechanism of photosynthesis. The chemical processes of photosynthesis occurring independent of light is called dark reaction. It takes place in Institutional review board essay stroma of the chloroplast. The Dark reaction of photosynthesis is drunk enzymatic and it is slower When does google report earnings next the light file. In dark reactions, two types of cyclic reaction occur..
Each type of pigment can be identified by the specific and of wavelengths and absorbs Powerdvd 15 ultra activation synthesis visible light, which is its absorption spectrum.
Many photosynthetic organisms have a mixture of pigments; between them, the reaction ppt absorb energy from ppt wider range of visible-light wavelengths. Not all photosynthetic photosynthesises have full access to sunlight. Some organisms grow dark where photosynthesis intensity decreases with depth, and certain wavelengths are absorbed by the dark.
Other organisms grow in competition for light. Plants on the rainforest floor must be able to absorb any bit of reaction that comes light, because the taller trees block most of the sunlight Figure 5. Each pigment can absorb different wavelengths of light, which allows the plant to absorb any carnegie mellon essay prompt 2015 that passes through the taller biologies.
Customized essaySo over here you literally have H2O. Now that the solar energy is stored in energy carriers, it can be used to make a sugar molecule. Keep in mind that the purpose of the light-dependent reactions is to convert solar energy into chemical carriers that will be used in the Calvin cycle. And I'm calling it that because that's what it is. The Dark reaction of photosynthesis is purely enzymatic and it is slower than the light reaction. And then from there, it keeps getting passed on from one molecule to another.
This chemical energy will be used by the Calvin cycle to fuel the assembly of sugar molecules. It takes place in the stroma of the chloroplast. The Dark reaction of photosynthesis is purely enzymatic and it is slower than the light reaction. In dark reactions, two types of cyclic reaction occur.
In dark reaction, sugars are synthesised from CO2. The energy poor carbon dioxide is fixed to energy rich carbohydrates using the energy rich compound ATP and the assimilatory power NADPH2 of light reaction. This process is called carbon fixation. Blackman first demonstrated the existence of dark reaction.