 So, my day job, I'm a biophysicist, I'm a PhD student in biophysics, and I look at molecular machines in your body. I know that kind of sounds unusual. I guess that's why I'm here for. We are talking about molecular machines. But before we start with molecular machines, let's start with the definition of a normal machine. A machine is anything that makes your work easier. It could be a pulley, which helps you lift a weight which is heavier, and you need less energy to lift that weight. Or it could be a sewing machine. You don't have to sew with your hands. Or it can be a more complex machine, a combination of machines, like a car. But if you look at this machine here, you kind of know how it works. You have the ropes, you have the rolls here. It's really intuitive what this machine might do. What's not intuitive is the human body. So when this guy, when we are trying to talk or walk or do any kind of activity, there are lots and lots of machines inside our body that are working to make us work. So in summary, you are a super complex machine, and there are trillions of machines working right now inside your body. And we'll only talk about some of them because we only have 15 minutes. Let's start with a really simple action. I mean, I look at my hand, I do this. I mean you just think about it and this happens. It's really intuitive. So how is our nervous system, so our brain is connected through our whole body through the nervous system, and how do we think about it and this action happens? So you know we do this contraction of muscles. You make this like biceps, you know, kind of bulges up. How does that happen? Let's look inside the brain and the nervous system, of course. It consists of billions of neurons, and these neurons are talking to each other all the time. So when I think about moving my hand, I'm doing that all the time right now, when I think about moving my hands, something travels from the brain to my hand, which tells me to move my hand, and it travels through the basic cell called a neuron. And basics of neurons are like this. You have a main body, this is the big stock, and the terminal of the neuron. And this part is what listens. So our brain is telling this part, okay, move the hand. And this part speaks. So what happens now? This is the first neuron. This is the second neuron. It's communicating. Third neuron down the line. So what's happening? The first neuron tells you the other hand. You've got to move the hand. It tells you the other neuron. You've got to move the hand now. And this goes all the way from my brain to my hand to move this. But of course, they're not speaking English. They are speaking using molecules here called the neurotransmitters. So in the terminal of an axon, there are molecule presence that are called neurotransmitters. They are present here. Even before you talk, they're always present. They're omnipresent. But there is one problem. Like I said, they are present here. But they are produced here in this main cell body. And they are present here. So how do they go from main cell body here of the neuron all the way through this axon to the very end? So these molecules, how do they go there? This is a drawing that I made of a neuron. Now, these neurotransmitters, these molecules that neurons are using to communicate among each other, what happens is, just like when you order something from Amazon, they pack it up. Yeah? So what neuron does is it packs the neurotransmitter up in this spherical kind of ball. And then this ball goes all the way through the neuron, comes to the very end. And the process is a little bit more complex. So it is unwrapped, in a sense, and then thrown out of the neuron to the other neuron to communicate. And this is what's happening here. This is called a synapse, by the way, for those who are interested. So this is happening. So how did that sphere travel from there all the way to there? It's done by this guy. So this is a motor protein called kinesin. And it takes that sphere. It's like a FedEx delivery guy. It takes that sphere and physically transports it from the main body of the cell along the axon to the terminal. Yeah? I'll give you a second to appreciate this. It's pretty cool, isn't it? Okay, so this is how neurons are talking. That was our machine number one, which we'll be talking about today evening. That was the machine number one. But what happens now, so I'm thinking, it comes to the muscle and muscular system is a little bit different than the neuron system, the nervous system. So what happens when the signal arrives at our muscles? So we have a signal arriving from the brain, so we thought. And now this neuron is connected to the muscles. Here you can see the neurotransmitters again. So this is how the neuron is talking to the muscles right now. And the muscle contracts. So this is a basic unit of our muscle, which we see here. We see thicker filaments, like this thick things, which are in the middle, and this thin things, which are connected to the walls of this basic unit of our muscle. And for contraction, there will be a sliding motion like this. So whenever we send a signal from our brain, it will contract just like so. And it's called the sliding mechanism, but sliding is not what's happening. If we zoom in far enough, we'll see, again, it's a machine. It's a molecular machine that is physically pulling the thin filament towards the center. And this is how our muscles contract. So we see they bind to this other filament called actin. The machine is called myosin, and they bind to the actin and physically pull the actin over. And that's how this action is happening. But, like, you drive a car, can't drive it without gas, yeah? Pretty straightforward, and nothing in life is free. Any kind of process that we do, I'm giving this presentation right now, I'm using up energy here. So where does this fuel come from? Where does this energy come from? Because muscle contraction needs fuel. And that's where the most important molecules, one of the most important molecules in our body comes in play. It's called the ATP. And what you can say about ATP is, it's A triple P. It's basically, so I'm oversimplifying here, of course, but A, there's three P after the A. What happens is, when we use up this fuel inside our body, energy is released. And one of the P's goes away. And now it's A double P, with a P on the side. So this is what's happening when we use up any kind of energy using the molecular machines inside our body. And we'll see how that happens now. So that's our machine. We have an ATP there. It's getting used up. So the energy is provided to the molecule. It stretches, and it binds to one of the binding sites on the actin. And in doing so, so these are the binding sites on the actin, and it pulls the actin towards the center. Now the ATP and P that are bound to this machine dissociate. And then the machine is waiting for another ATP to arrive, because of course it needs energy to do this action, like a rowing a boat. So all of them are kind of doing this action repetitively. And see, so ATP comes, gets used up, and this action goes on. And macroscopically, so all of them are doing this action, all these basic units. And if you zoom out, this is what happens. Our muscle kind of bulges up. So this is what's really happening. This is the fabric of life. Really macroscopically, there's a lot of machines working right now. So this was our machine number two. But these machines, two of these machines which I told you about, and thousands of other machines in our body that are working right now, all of them use ATP. Where does it come from? So we used up ATP. We are actually using more than our body weight in ATP per day, more than 80, 90 kilos of ATP we are going through per day. Where does it come from? So our body is really good at recycling stuff. So we produced A double P from A triple P. What our body does is it takes the other P and connects it again. Pretty straightforward. But to understand how it works, we have to look at one of the really, really ancient pieces of technology. So right now, if you want to produce any kind of electricity, with the exception of solar panels, everything we do from very old to the very new, we spin a turbine. We spin a turbine, we connect it to a generator, there's magnets inside, and it produces electricity through this motion. Very old, like a water wheel, a very new one, like a nuclear power plant. The heat up the nuclear material, the steam goes here, and the generator generates electricity. So it's really, really primitive. But when I say seriously primitive, I don't mean made by humans. I mean billions of years old, because nature did it first. So there are boundaries in a cell that looks like this. And instead of water, we have protons. There's more protons on one side, there's less proton on the other side. And what nature wants to do is these protons really want to go to the other side. So they are equal on both sides. What we do is, if there is a hole here, the protons will kind of escape. So what nature does is it installs a turbine in the boundary. And it looks like this. So we have more protons down here, we have less proton on the top, it installed a wheel in the middle, a turbine. And the protons in the process of going towards less protons spin this wheel. And again, this is happening right now inside your body, trillions of time. But spinning a turbine is not enough. You have a turbine here. It has to be connected to a generator. So this kind of generator, we traditionally use a rotating magnet. But this generator, what it does, it's really interesting. It converts it into ATP, and the ATP is thrown out for us to use. Now, this will be the whole machine which we'll be looking at. So we have more protons on the bottom, we have the boundary, and we have less proton on here on top. Now, everything is moving about. And we see, we install a machine there, right at the boundary. And it's rotating. And it's doing something to the generator. It's called F1FO ATP synthase, this machine. And it looks like a mushroom. And what it's doing here is, it's taking in ADP and P, and it's throwing out ATP molecules. So this process creates ATP from ADP and P. But what's happening inside the generator? And I repeat this slide again. We have ADP and ATP just floating in the solution. They randomly go inside the machine, makes ATP, and it's thrown out. So imagine a guy sitting in the office, and his sole job is to take ADP, ATP, ADP and P, connect them together, make an ATP, throw it out. And do this again. It's like an assembly unit. And in microscopic detail, it looks like this. ADP comes in, P attaches. It gets thrown out. Comes in, gets attached, thrown out. Happening all the time. Even right now. Pretty cool, huh? And like I said, I mentioned in the beginning, these are only three machines that I will be talking about in today's talk. But this talk was supposed to provide you with a starting point, with the basis that, yes, there are machines inside our body. And across all domains of life, there is an estimate of 70 to 80 million different machines, different kinds of machines that exist. So the functions are diverse, and the possibilities are endless. So please, I urge you to just go on YouTube with trusted sources and check these machines out. They're amazing. And to kind of recap our presentation. So we learned how the walking guy, Keneson, transports the material that the neurons need to talk. Or how the arm muscles contract using these machines called myosin. And also this machine, which makes all this possible. Thanks. Thank you. Thank you, Royte. We are now happy to welcome some questions. Yes, please. Can I just explain what is ATP? So ATP. The question was, can I please explain what's ATP? So ATP is a molecule. It's like Euro. You need to do something, you need to pay with Euro. One Euro is one ATP in our cell. So if the machine needs to work, so for example, this walking guy, if it needs to take one step forward, what it does is you insert one Euro, and it will move one step forward. You insert another Euro, it will take one step forward. Like that. So it's an energy source. We can discuss this in detail in the pause afterwards. I don't want to bore others. Thank you. Let's see. There is another question. Yes. This topic is super interesting. But comparing this to a machine, you know this is more efficient than man-made machines. But if you could quantify about the time frame in which this happens, is there any research? Like for example, this happens in milliseconds, you know? Like I'm just interested. This question is really specific, and we can discuss that. It might not be interesting for everyone, but we can discuss that in the pause. Please come find me. I'll be around. Yeah. Okay. Yes, please. What kind of information do neurotransmitters carry? So the question is, what kind of information do neurotransmitters carry? So there is... When a neuron is talking to another neuron, there is thousands of neurons talking to this one neuron. Some say yes. Some say no. They are either exciting it or inhibiting it. It's what they're called. And so you can say a neuron has an analog and a digital side. So while it's listening, it's listening to all yes, no, yes. And there is a thing called action potential inside on neurons. And when the action potential is reached, it transmits just one signal. In detail, we'll talk about it in the pause. There is a lot of food for talks already, right? Very good. Yes, please. So my question is... I like the talk, but I don't want to see. Neither. I'm wondering if you know... So the question is, how were these video generated? So we can never see these. It's the physical limitation. We can never see what's happening. What we can do is, looking at it from different methods, that we can look at these machines. So we use, for example, X-rays to find out how the machine looks like. Then we use another mass spectrometry to say what's the sequence, what are the amino acids inside the protein. And then we can... What I do, for example, I built a microscope, which looks at the process of replication. So we can only look at it indirectly. And then we piece all this information from six different methods together and build a video. This is only an artistic representation. I didn't make the movie. I found it online on sources. There are other labs that make these movies. But yes, these are totally accurate. They are an accurate representation of what's happening inside the cell. Yeah. Okay, thank you. Yes, there's another one. Very good questions tonight. So the question is, what happens to neurotransmitters? They are released to move the muscle. What happens to them afterwards? So they are used to transmit signal onto the other neurons. But again, they are produced in the main cell body. So they are used up, produced, used up. Maybe I can also partially answer additionally as a neurobiologist. So there are two main things that might happen to these neurotransmitters when they are released. It's either they're then destroyed within this outside compartment so that they don't affect anymore after a while. Or they can be taken up back into the neuron and will be loaded again into these vesicles and then can be reused. Okay, I think we will stop here. There's already a lot of things to ask Freud afterwards in the break. Thank you very much, Freud. Thank you.