 Photosystem 1, come and at you. First of all, I mean photosystem 2, come and at you. First of all, I have a little visual here for you of an actual chloroplast. This is an actual phylochoid, and you can see that it's made of cell membrane, and these are my photosystems that are embedded in the membrane. And so I just wanted you to have a sense of what they actually truly, truly looked like. Okay, instead of just the windified version, which that's okay, we're going to do the windified version too. Here's the scoop. Are you ready for the madness? Of course you are. The scoop is that I'm going to have my phylochoid membrane down here at the bottom. This is my outer phylochoid membrane, and this is my phylochoid space. Phylochoid, seriously, space. Okay, that's going to be important. And this out here is my stroma, and I'm going to draw you my photosystem 1, and it looks just like I showed you because I'm a nerd and that's just how my brain works. And no picture of photosynthesis is complete without a sunshine. And there's my little sunshine shining down light onto photosystem. Dang it! It's not photosystem 2. It's photosystem, I mean, 1. What? It's photosystem 2, dog pounds. Look over here. Menu says photosystem 2. No matter what I say, this is photosystem 2. Here comes the energy. Now I have to pick the right color. Yellow all over again, there. Down comes light energy, like a little fairy godmother. But I forgot to tell you, like, what is the point? You, this is going to blow your mind. Guess what is in the core of photosystem 2? Like at the base, there are electrons in there, two of them, and they're just chilling. What? They are? Yes. They're just hanging out there and everything about the photosystem funnels energy down to make them what do you suppose? High energy electrons, seriously. And this is where it becomes even more like a trampoline because the energy from the sun comes down, funnels down, and the photosystem, all the proteins in the photosystem are funneling the light to these two electrons. So all this energy is like getting them all kind of fired up and getting kind of crazy and pretty soon, no joke. Boing! They get flung up into the air. They are like two up in the air electrons. Now tell me, what kind of electrons are they? How about high energy electrons, dog pounds? Yeah, it's true, they are. Now high energy electrons, how do they get high energy? They collected the energy from the sun. As opposed to the high energy electrons in cellular respiration, where did they get their energy? From glucose, from the chemical bonds in glucose. So now we've got high energy electrons. Thank you very much, Mr. Sunshine. And what do you think we're going to do with them? How about, what is this? Why not? Let's throw an electron transport chain into the mix. And so these little electrons get passed down to an electron transport chain, and they're high energy electrons. So they're going to do exactly what they do in cellular respiration, which is what? Yes, they're going to pump protons into the thylakoid space. Oh my gosh, can you see why? This is like, this is old school. We got this. What you talking about, Willis? We've been here done this before. High energy, now, what are we going to do with them? We know exactly what we're going to do with them. We're just reviewing now. This is ridiculous. Let's pass them down. Let's grab some of the energy from those high energy electrons, and let's use that energy to do a little pump, pump, pump, pump, pump action. And pretty soon we've got an amazing, like, collection of protons. We're creating a concentration gradient, true story. Keep passing these puppies along. Why not? Keep pumping. Why not? Why? Why pump? Well, there's a lot of things that we could go to with that one. I'll try to avoid that if at all possible. I don't know why you'd want to pump, but why do we want to pump protons? Here's why we want to pump protons. Who's this guy? You know this guy, too. It's ATP synthase, and ADP plus P is turning into, okay, I'm going to put my ATP up here just for the heck of it, ATP. Do you feel like, dude, I knew all that? It's easy, isn't it, once you know cellular respiration? Okay, there are a couple of questions that you should probably be asking here. We need an electron acceptor, don't we? So be thinking about that. Who's going to accept these electrons? I want you to know that we actually gave up electrons here. These electrons got passed down. We need to find someone to accept them, but we also are going to need to replace those electrons in Photosystem 2, and I want you to think about that. I'm going to come back and we're going to look at Photosystem 1.