 All right, does this look familiar? Well, it shouldn't look super familiar, but it should be like, oh, we've got, we've got an animation coming folks, and it's true. We're gonna talk about photosynthesis. And of course, the first thing we have to do is orient ourselves to the parts. The first question that I have on here, and again, like for me, when I look at the video version of this, I can't see that for do-do. I hope it's big enough for you. But the first question is, what is the equation of photosynthesis? In these animation reviews, I really encourage you to push pause when a question comes up and challenge yourself. Like, can you pull this stuff out from memory? Can you pull it out from all the stuff that we've talked about so far? It's really good practice to try it. Because then, I'm going to tell you the answer. Here is our equation for photosynthesis. And I'm just gonna keep that equation up in the top corner, just like I did with cellular respiration. So we can remember, we actually have a, like we're gonna see where all these things come from. Next question, of course, is where does photosynthesis take place? Again, that should be easy to answer. When we talked about cellular respiration, we were like, well, mitochondria mostly, but also cytoplasm. In photosynthesis, we're 100% dealing with the chloroplast. All the parts and pieces happen in the chloroplast. Okay, the next question is, well, let's go ahead and label chloroplast parts. And this part, I am gonna be terrible at. There's eight things to label on this very diagrammatic version of a chloroplast. Push pause, draw that little goofy chloroplast out, draw the arrows, label that diagram. Doing the work will help you, but I'm just gonna go ahead and bounce us into the answer just so we have some perspective. Some things that I wanna make sure you're cool with, take a look at number four. I don't know, can you see my, you can. I think you can see my mouse. So number four is the stroma of the chloroplast. And I did, once again, I color coded our big picture where we're going to lay on all the pieces of the photosystems. So this right here also corresponds with the stroma in the chloroplast. Notice eight is the thylakoid lumen. And this whole, we've got three thylakoids in number six is a granum, one granum. And we actually have three grana in this picture, but one of the grana only has one granum, only has two thylakoids. The other two grana have three thylakoids, holy cow. I think I did point to these structures. That's so busy and crazy. So that you could also see them in the big picture. Here's my thylakoid lumen. So you can see that we're just zooming in just like we just did with the drawing we made. And I did that on purpose so that we could practice this stuff. I took a slice right here. You can see this little box. I took a slice of the whole chloroplast, one chloroplast part, and I blew it up. And that's what we're seeing and that's where we're gonna draw everything in. All right, I am satisfied with your drawings. I have left a label for the cytoplasm so you don't forget that the cytoplasm is that white space out there. It's out there. It's not gonna be any part of our story, but it's there. The stroma is the light blue stuff. And then I included the thylakoid lumen. I just don't want you to forget that that's the space that is significant for this process. All right, let's see if we have another when our next question comes up. We're gonna deal with the light reactions first. Think through, like what are the light reactions doing? Capturing energy from the sun and turning it into ATP, capturing it and putting it in ATP and high-energy electron carriers. There's the sun. Oh, and of course we start with photosystem two because it's first, but they discovered it second. There's photosystem two and what do you see in the middle? I see two tiny little electrons down there. Can you see them? They're just hanging out little electron guys. What are you gonna expect to happen first? Well, I mean first we have to add our electron transport chain complete with ATP synthase. So I think about that one ATP synthase as working with two different electron transport systems because the two different electron transport systems are both working on that hydrogen ion concentration gradient. Okay, let's see what happens. We start, oh, we're gonna build the whole thing, I mean. Of course, we're gonna build photosystem one in here as well and throw in its electron transport chain as well. Okay, so now you have all the pieces and now we're gonna throw in sunshine and notice how I've got the sunshine. It's energy, it's coming from the sun and we're just gonna funnel energy into the reaction center. Look at how I'm doing this. Now watch carefully, watch what happens to these electrons. I don't know if you guys can see this, but I hope it's big enough. Watch what happens when that energy from the sun hits those electrons. Just a little bit of energy gets captured in the electrons and we're gonna do it again and we can do this all day because of copy and paste in PowerPoint. But here comes another one. We're gonna go ahead and each time we're like soaking in energy from the sun, those electrons are getting a little bit higher and higher energy and this is all happening because of the reaction center which is made of chlorophyll. It's just phenomenal. Once we get enough energy, we launch those electrons into the sky. We don't actually launch them into the sky. They just now are high enough energy and I'm sure that there's no launching involved but I just love the visual of launching them out of a trampoline that was powered by the sun. All right, where are they gonna go? Look, what are the pink electron transport proteins gonna do with this energy? So the energy is going to go to the transport proteins. You should know the answer to this. What are they gonna do with that energy? Ta-da! And I made it happen like magic. They are gonna create a proton concentration gradient, a hydrogen ion concentration gradient and all of them keep doing it and I'm not going to illustrate it but remember I did illustrate it in the cellular respiration review. So if you're like, wait a minute, I wanna be able to visualize what happens with those hydrogen ions, go back to that one and watch that because I walk through each one because I didn't have to do it 12 times. We have another question. Let's see what this one says. What will we do with the hydrogen ion concentration gradient? Well, it looks to me like we know. ATP synthase knows what to do with the hydrogen ion concentration gradient and takes ADP plus P, which it's everywhere because everything is using ATP so that's just gonna be available and it's gonna turn it into ATP. So now we've got ATP. We don't have a final electron acceptor for photosystem two, for that electron transport chain. We don't have a final electron acceptor. So who's it gonna be? And we talked about this, didn't we? Whoa, that was fast. Photosystem one is the final electron acceptor. You can go back again to that cellular respiration review where we visualize the log jam that happens if you don't have a final electron acceptor. Here we're just going, we're just following one set of electrons through but we would have a log jam and the whole thing would stop if we didn't have anywhere to put those electrons. So thank you, photosystem one, for taking them. Okay, guess what's gonna happen next? It's the awesome process of energizing those electrons and it's happening just like the last time. Now we have these high energy electrons that get launched that provide energy to the electron transport chain to pump more hydrogen ions into the mix. But the next question is, who will be the final electron acceptor for photosystem one? And so it can keep going. Photosystem one was the final electron acceptor for photosystem two. Oxygen was the final electron acceptor in cellular respiration. Who's gonna accept our photosystem? There's a hint. Can you see it? I don't know if you can see that little guy right there. Somebody's coming onto the scene. Who knows is that? It's our favorite guy. It's an empty electron car. The electron carrier is here to pick up the electrons and now we have this high energy electron carrier and ATP. Are you kidding me? And the next question is, what will we use the ATP and the high energy electrons for? We're sending them to the Calvin cycle and I didn't draw that out either. But in the Calvin cycle, those guys are providing energy for Rubisco, the amazing enzyme, like the best enzyme, the most valuable player, enzyme. To use to make glucose out of carbon dioxide. Okay, we're not done because they're gonna leave, but we still have the question of how are we gonna replace the electrons from photosystem, from photosystem two? We gotta have some electrons and I know you know there's your hint. Who's coming? Who's gonna show up? What? It's water! And what's gonna happen? The water is going to split up and turn into hydrogen ions. Those are handy. And do you see the little electrons right here? Electrons are gonna go replace those in photosystem two. Oxygen is like peace out home kids. I'm headed out, I'm headed out the stomata to help out those crazy animals out there who need me and thank goodness that this happens. I think, thank goodness I have a V end slide because otherwise I could have kept going. Okay, you can watch that as many times as you want to to practice because I think I gave you enough time to answer questions. Oxygen, why do we care?