2x03 W2 L3 Lecture Transcript PDF

2x03 w2 l3, lecture in person Wed, 01/15 09:34AM · 40mins Transcript With a proton of hydrogen. Because. Each soil. Most of our body is water, so oftentimes we try to interact in this way, and it sends that proton in motion. So again, this total kinetic energy is conserved. This is the most pred...

2x03 w2 l3, lecture in person Wed, 01/15 09:34AM · 40mins Transcript With a proton of hydrogen. Because. Each soil. Most of our body is water, so oftentimes we try to interact in this way, and it sends that proton in motion. So again, this total kinetic energy is conserved. This is the most predominant interaction process with stock income. With those high energy costs. Mostly elastic scattering. Okay. There's another type of interaction. If you have elastic scattering, there's also inelastic. Scatter. And if you have elastic scattering or the kinetic energy is concerned in elastic scattering, there's some energy loss, essentially, and that energy. Is basically going towards overcoming any binding forces that are holding that nucleus together. So what happens is there's some transferred energy using the number overcoming that binding force. So. The initial kinetic energy is going to be less than the total kinetic energy after the interaction, so for demonstration. If we have ten on this side, right? Let's say this is three here, three here, three here. The total would be nine. Right. One part of that energy would go towards. Essentially dividing up that nucleus, okay? We really go into it, it gets a little bit quantum mechanic, so we won't go. Too far in depth. But essentially, when it breaks apart that nucleus, this usually happens with carbon and oxygen to very prevalent. Types of atoms that are in the body or in the room. The nuclear fragments that are injected are alpha particles. And we talk about Elf Parkinson's. Why can't I remember? I think we talked. About all the particles we did, right? Basically, they're stealing of atoms is essentially what it is it has two neutrons and two protons. Okay, so if you have a high energy neutron coming in, and it breaks up this carbon atom, right? And let's say the atom. Number. As you probably know, carbon is twelve. It breaks it up into. Six. It breaks up into two. Two, two. Okay. So you have two neutrons, two protons. It's essentially a helium atom. All right? That's when else, barklet. Those alpha particles are particulate radiation, right? So they can go on to further interact and further. Ini or further damaging tissue. These alpha particles after an inelastic scattering are known as splatoon products. It's sold out here. Malaysian products. Just when heavy nuclei emits large number of nucleons. Nucleons are either protons or neutrons or both. In this case, in alpha particles. Or. That results from being defined. High energy partner. That's what splatient products are. So it reduces the atomic weight, goes from six, thus the atomic weight into. Essentially two. Two. Or if it's oxygen, it goes from atomic weight of e and splits. Up into 2222. Yes. Let me just quickly re explain. Desperation products. This flavor product, Slater products are just essentially. Protons, neutrons, or both. When. A heavy nuclei emits it after being hit by. A high energy particle. Such as raising apartments of that initial heavy nuclei. This occurs above six megaelectron gold. And as your neutron energy, your initial neutron energy rises. The prevalence of this also increases the likelihood of it happening ultimately. Any questions about that? So as you. So this generally occurs about six mega electron bolts of energy for that initial neutron. And. As that increases above six mega electrons also gets more likely to occur. Any other questions about that? So. There are two concepts. There's actually four concepts we're going to talk about today. And people get those confused all the time, so we're going to lay it out very clear. Make sure you don't get those reviews, okay? We've probably talked about and. You probably heard about directly ionizing radiation. Directly. Ionizing radiation is essentially a collisional interaction of electrostatic field that causes ionization. So that's important. It has to essentially have some sort of charge. The initial particle has to have some sort of charge. Powered by Notta.ai To deflect, let's say the electron. And cause an ionization. Generally speaking, high energy charged particles are directly ionic. That's like high energy electrons, protons. Alpha particles. If you have different types of ions, like an iron ion or something like that, those are heavy. Particles. They're charged particles. They interact. They ionize directly. That's directly ionizing regime. There's also indirectly ionizing radiation, and this is that energy transfer. That causes a release of energetic charged particles, which are then directly ionized. So usually this occurs with photons. And uncharged particles, which are neutrons, right? So essentially what happens is you have your photon come in. It gives up its energy. So that's what is massless. It doesn't have. Any. There's no weight to it. There's no mass to it. It gives us. Its energy converts it into, let's say, kinetic energy. For that electron, and then that electron can then go and be directly eye. Okay, so it's. Kind of like a two step process. That's indirectly ionizing radiation. That would be x rays, gamma rays, any electromagnetic radiation. And then neutrons as well. Because neutrons are not charged, they're neutral. So they interact through an indirect, inizing way. Any questions of those two concepts? You probably heard before. Important point to note is that any sort of radiation is injury to an organism. Always begins with chemical changes at the atomic or molecular level. I always think of it like. It starts with physics, with those, whether it be particles or electromagnetic waves or whatever may be that's physics when it's interacting with the app. Because of the change and the ionization. It changes how different molecules interact with one another. It changes their bonds. Maybe it breaks some bonds. Maybe it's cause it's bonded correctly. That's kind of a chemical change. And then eventually, later on, you get to a biological result. So it's almost like physics. Chemistry, biology. Right. So because those molecules aren't either working the correct way, maybe the proteins. That it's creating aren't working correctly. Maybe 50 years down the line, there is some sort of. Ongoing change. Some cancerous tumor that's developed, that's a biological effect. Okay, so. I like to think of it as physics, chemistry. Wow. All right, so it says ionization to broken chemical bonds that can change the molecular structure. And then you have to change chemical behavior. Okay. We need to understand why. How this happens so that we can better protect ourselves. And our patients. Right, because ultimately, these things can lead to mutations or cancer or terrible effects. All right. You increase the chances of these changes happening on your watch? If you're not mindful. Of the proper radiation protection practices. That's why this costs until. We're trying to very much minimize it, not just to our patients, but to ourselves. Coworkers faculty. Coworkers, things like that. No questions about that, right? That kind of makes sense. Now. We'll talk about radiation and stuff. What do these changes look like? What do they mean to our bodies. And again, I want to keep two things very straight when we go into this, remember, directly and indirectly ionizing radiation. Remember those two concepts in the back of my we're now going to talk about indirect action and direct action, and that's talking about how radiation. Essentially interacts with the cell itself. Okay. So generally speaking, the effect is mainly due to damage. To biological macromolecule. In this case, it's DNA, RNA, potentially proteins. These are our critical targets, and we'll talk about critical target theory later on in this lecture. For us. We're usually talking about DNA as our critical target. Okay? That is what encodes genes. That is what essentially tells us what to do, how to make proteins, things like that. That is. How it's going to cause some sort of biological effect. Okay, so the target, our DNA. This is our DNA key list, right? It can be damaged by direct action. Or indirect action do not confuse us. The indirectly ionizing and directly ionizing. Those are two different concepts, okay? If it's direct action. Okay. Essentially, the radiation comes and interacts right away. With the target molecule. All right. With the DNa helix itself. Right. So this is showing the radiation. Affecting an atom within the DNA healus itself that's directly. Direct action, okay? Indirect action is where the product of radiation. Are interacted with other molecules. Okay, that's indirect. So in this particular case, it's. Showing a photon interacting with a water molecule. Powered by Notta.ai The byproducts from that interaction, then go on to damage the DNA helix that is. An indirect action. And we'll go into more depth in this lesser, okay? I do want you to keep in the back of your mind. High le t radiation. Deposits energy very easily. High LEP. Usually something like elbow particles is a good example. High Lep radiation, very big. Nuclei. It's a large atom. It can be stock variant, but you can actually stop alpha. Particles of sheet paper. But it gives up its energy very easily. And a lot of energy in a small area. Low lecs. We usually are. Like low energy x rays, gamma rays, things like that. It deposits energy. Not as easily. It usually moves further through materials than, say, like an awful part. Gamma is actually do need like lead to soften or really thick concrete. Okay. Just keep that in the back of your mind and just make sure you don't confuse. These two concepts. Indirect action, direct action with indirectly ionizing and directly eyeing as radiation. All right. I did that one out of the student and. The rule of hurt for me. Okay? No questions about that making sense for it. Okay, so again, direct action. Talking about it. Energy is absorbed by the macromolecule itself. In this case, DNA ionization or excitation results, the chemical bonds. Right, usually between. The nucleotide bases. Right. And the chemical behavior of that macromolecular change, if there's no repair. And we'll get into repair processes and things like that, but. Generally speaking, that is direct. Action. Phenomena is directly affected by photon, by particulate radiation. There's no middleman. All right? There's no in between process like there is with indirect action. With indirect action. You have an x ray photon interact with. Really, it's anything other than the DNA helix in our case. Oftentimes it's. Water. Okay, that creates something called a reactive free radical or potentially some sort of cytotoxic. Byproduct and. That can diffuse through. The cell. Relatively small distance, but if it's close enough, it can interact with the DNA deal. Okay, so it's something to keep in mind. So it's not the photon itself. Hitting the macromology. So it could hit somewhere very close to the macromolecule in the cytoplasm. Or something like that. Over here, and then it just moves a little small, very small distance to hit the macro. Okay, so this has some sort of middleman. Or indirect action. Why is it usually water? Why is it frequently h two? Yes. Because most of the cells made up of water. Yeah. People were like, 80% water, according to haul. All right, yeah, that's absolutely correct. If someone's have a whole bunch of water in. There's a whole bunch of h. Two o so oftentimes, if it's going to interact with something, it's going to be that water molecule, okay? It can form. Slightly plastic products, meaning free radicals, or potentially, H 202 is hydrogen peroxide. And you heard that. Joke. Where chemist walked into a bar and orders h 20 and another kind of comes in in order. To H 202 and he dies. That's that it kind of sounds, but get it used to it, too. As in, like. Hydrogen. It's all right. It wasn't my best joke, but anyway. Essentially. These. Cytotoxic products can migrate through the cell to damage the critical party. Now, if it's occurring far away. There is. A distance that these things can actually dictute through the cell, right? Usually if it's towards the edge of the cell, it's not going to offer. The. Name Helix, but this is. A potential outcome. Most radiation interactions are interact. Okay. So most of the damage that occurs is through this indirect action. And there's a nice diagram over here that's showing you the extra focus on. Interaction molecule. It creates ions and free radicals. The free radicals kind of go on with indirect action. To create toxic substances that end up damaging the DNA. Macromole. So either direct, like, two radicals themselves, or through those toxic substances that are created, and then there's biological damage. Theoretically, the ions can also damage the DNA, macromolecule, or sometimes water is just reform, which is convenient. And then there wouldn't be any biological damage if it just reforms the water. When I say free radical. Free radical. What does that make your name, though, when I say the term free radical? Yes. Something looks like uncared electron. Yeah, you're absolutely right. I think when I think. Free radicals like something that radical. Powered by Notta.ai It's free. It can go on to interact with a whole bunch of stuff that wants to get free. It's like. I don't know how else to explain it. It's free. It wants to go hang out with everybody. It's a wild molecule. All right, that's. What we're picking up. And. In correct terms, it does. Unpared electron. You're right. So that's what I think of when I hear free raffles. So it's an outer molecule with an unpaired electron in the outermost orbit. Do not confuse this with an extra electron. Extra electron would make it an ion. Right. Meaning that it would be negatively charged. It had an extra electron. This is simply an unpaired. Which means it just doesn't have a budget. Okay, use the electrons. Have buddy. These are highly reactive chemically because. They want to find a buddy for that electron electrons. Like I said, like. Pear that makes them stable, because this doesn't have any sort of. Additional electron. It's highly reactive. It has a very short lifespan. Because it reacts so quickly, they don't. Exist for very long. They are able to migrate through the cell to a distant site, and these can cause those bond breakages to another molecule to obtain a second electron to achieve stability. So it's going to take work off. It doesn't care. It's taking whatever it can get, all right? So. The actual radicals are neutrally charged. They don't have a charge. Very reactive, but neutral. Remember that. In your textbook or in the diagram, you'll see an aspect for a dot that denotes the radical state? I don't know. I just prefer the little. So that's just kind of showing you that unpaired electron. Any questions about this? Yes. Technically speaking, the atoms, I guess. Say that again. It's louder. The difference is kind of theoretical. And ions wouldn't say to be seeking the atoms that gives away the recon. Technically, it's an ion free radical, but let's just keep it as an ion. For our purpose. So it would be an ion theoretical, but let's just keep it eye on and pre. Radical. Okay? Just to keep them separate, not confusing, all right? Okay. The specific term for breaking apart that water molecule y radiation is called radio license. Olympus is like a puppet land suffix that means, like, breaking apart. Okay. There's a kind of long diagram on the left side here, and I'm going. To break it down step by step, part by part, so that we're all on the same page. There's no confusion. Okay. The very top is that initial interaction where you have your X. Ray photons. And you have your h 20, right? So you have two hydrogen atoms and an oxygen out of. Right? That's your water bottle, h two. And remember, when we're talking about ions, that's where the total number of electrons. In its shells do not equal the number of protons in the nucleus. Right. Then it has some sort of charge associated with it. Okay. So the initial ionization, you have h two and radiation, it's going to break that. Molecule. Into a water ion, a positively charged water ion, and an electron. All right, so basically, the protons. Come in, it has liberated an electron. Now the electron can go on and interact with things. So note it's color coded, so you have blue. That's our initial. Initial interaction. And then we have red, which is showing the positively charged water molecule right out here. And this extra electron, okay? That's what this is talking about. Part three. And sort of part four is when the free electron, this guy here. Goes and interacts with another water molecule because there's a whole ton of water molecules. Around. So it's likely that that electron will interact with another water molecule. Okay, that then. Becomes a negatively charged water molecule contained. So. Our two sort of cases that occur. There's actually a whole bunch of different cases, but. Our two main ones that occur is we end up with a positively charged water molecule, and we have a negatively charged water molecule, right? Both of those charge water molecules are reactive. Okay? They tend to interact with things. They tend to. Disoj because they're not stable. They want to be stable. Any questions about that general idea or overcooked? Still with me, right? So part two, you have this positively charged water molecule, h tool plus, and then it says, or hoh. Plus, it's just another way to write it so that you can see how it breaks down into two different products. When it breaks down or dissociates, it creates a hydrogen ion. And a hydroxyl radical. Okay, so that h two positive breaks down into a hydrogen ion. So it's a hydrogen. Ion with a positive charge. And something called a hydroxyl radical. So that's the way one option, one hydrogen. With an unpaired daily Powered by Notta.ai electron. This is still neutral. The OH is still neutral. The hydrogen ion is positively charged. I forget. Which textbook it's in, but. If you have. The positive water molecule interact with regular water. You will also get. A hydroxyl radical. That's another sort of pathway that can take. All right, so that positive charge water molecule. Interact with another water molecule, so there's a whole ton of them. You'll end up with. The hydroxy rat core as well. That's what this last one saying. It's also possible. Part two. And it doesn't necessarily need the exact same. Ion electron pair that created it, but because of the topping, theoretically it's all over the place. Right. There's many, many photons that are interacting with many, many byproducts. That are being created. You can have this electron or unelectron interact with the positively charged water molecules and just go back to regular, stable water. Okay. So it just basically recombines. All right, that would be a stable molecule, no damage. No worry. There's no byproduct, right? We're okay with stable water. That's another possibility. Moving on to that last sort of section where we have. The electron from part two interacts with another water molecule. That water molecule will then have an extra electron. Okay, so now. You have a water molecule that is negatively charged. Okay. That negatively charged water molecule is also not stable and tends to break down. Into a hydroxyl ion, so. Oh, negative. And a hydrogen radical. So hydrogen with an unpaired electron. This is not mentioned in the hall tax, but you do need to know. All right, so you essentially. Get the same. You get, like, a hydrogen and you get a hydroxyl, it just switches. Whether. It's a hydroxyl ion or hydroxyl radicals versus a hydrogen ion or. A hydrogen. Just keep those two things straight, okay? Any questions about that? That is essentially. The major points of radio license. There's a few other interactions that we're going to talk about. So that's hydrogen radical that we just got from this last part here, part four, that. Hydrogen radical can combine with oxygen. So another prevalent molecular atom that is present in the body. And. Itself. Is oxygen. Right. They can combine with two. To form a hydroperoxyl radical. So then you have ho two with this little dot that's known as a hydrofaroxal. Radical. So that can also go on and interact and damage the dena. Okay? We have a few different ratchets. Hydroxy radical hydrogen, radical hydro peroxylvac so far. We also have, and we mentioned it. Hydrogen peroxide being created when you have two hydroxyl radicals interacting with conduct another. Right. So those two extra electrons, not extra sprite, those two unpaired electrons get paired up. And then you have h two. Two hydrogen peroxide, which is cytotoxic. It's. Damaging to the. Cell. That can also go on and interact with the DNA double D A. So, to recap, Possible damaging product of radio license. We have our free radicals, hydroxyl, which is just. The hydrogen and hydro broccoli. That's three free radicals. And we have one cytocoxin compound, which is hydrogen. There are actually a number of other byproducts that are created through radiolicis. But just for the scope of. This course. We're just keeping it with these. These are the main ones. These are very. Prevalent. Any questions? Sorry about that. Anything? No, we're all good. Yes. So it's just a cytoxic damaging to the cell, essentially. So hydrogen peroxide itself is stable. It's like a stable molecule. It's just. Damaging to the cell. Whereas hydroforexy hydrogen and hydroxyl have that. Unpaired electron, and so they're very reactive. It's not necessarily like hydrogen. Peroxide. Very reactive. It's just damaging to biological. Any other question? We do have to talk about the oxygen effect. Generally speaking. Oxygen, or the presence of oxygen, extends the lifespan of free radicals because it reduces the likelihood of those free radicals recombining with H two o. We like when those three vessels we combine. If there's oxygen present or is it an oxygenated environment? It's like an enabler. All right, options like an enabler. It makes things worse. It extends the life of preventive, makes it more likely to go on and cause interaction. It's more likely to interact with activist. There's experiments that are done in vitro, so. In little plate of cells where they have Powered by Notta.ai it, in an environment where there is no oxygen deprived. Of oxygen in an environment where there is a lot of oxygen. And if you get the same amount of radiation, you end up with increased damage when there is oxygen present in oxygenated environment. Okay. Yes. How would oxygen be. How would oxygen be able to send the work? You can think of it as. Like. You think of it like this. Just to keep it simple. If you have a lot more oxygen, it's more likely to turn into, like that. Hydro peroxy. Retinal. So there's still more rational. Okay? Think of it like that, all right? That's why oxygen can be more damaging. Okay, so, generally speaking, sequence of events or indirect action. By a photon. You have, the instant photons come in, interact and causes the release of a fast electron. Now that fast electron is able to go on and trigger the breakdown of a water molecule, all right. This creates a free radical. And those free radicals interact with the critical target and break those chemical bonds that are present there. All right. We'll go into. The structure of the DNA itself. But just know that it can break the temporal bonds essentially holding that DNA double dips together. And then the biological expression of damage occurs, and this could be in a matter of hours. It could be in a matter of days. It could be something that doesn't affect the person. Until 30 years, 40 years down the road. All right. This kind of idea leads us to cardic theory. The fact that. When dna is damaged. Myelogical hydrocarbon. Why do we care about indirect access? It kind of brings us to the target theory master model. So, essentially. DNA, as you all probably know, carry genetic information for cellular repetition, and it regulates cellular activity to direct protein synthesis. Those are the instructions. It's literally the instruction. There is a bunch of different. Well, there's proteins that breathe the DNA itself. And allow for more co tools to be produced. All right. It essentially gives the cell its function. Rna is kind of a single strand of the phosphate and sugar base and it carries DNA's. Information from the nucleus to the rhinozonics for protein synthesis. So we do have some RNA as well. But for most of our purposes, we're talking DNA and eukaryotic. Cells. Okay. The master molecule. The idea is that all these other proteins and molecules and things like this, something. Has to. Give them instruction. Something has to create them. Something has to tell the cell itself to make this. Stuff that kind of essentially means there's some sort of master molecule. There's something. Giving the instruction. Has anyone ever taken. That's the thing how absolutely crazy it is that were made of. Cells that are not thinking. They have no brain. There's nothing like that. It's simply a bunch of chemical. Instructions. That create us, that our body functions at all. It's absolutely wild to think about. Take a second to just think that we're a massive cell, trillions and trillions of cells that are somehow existing and have consciousness. This is getting into, like, I don't know. Psychology. Or is it? Why is it not psychology? Philosophy. Thank you. Thank you. Okay, so protein, again, determines cellular characteristics and function. That includes. So it's a DNA damage. It can affect structural protein, different enzymes, hormones, antibodies for your immune system. Disinfect other things that are in the cells that are dependent on proper or correct DNA. Replication. So we need the DNA that is proper and correct to continue to be replicated accurately. Otherwise, it can affect these things. Yes. Target theory is basically just saying that there's all these molecules and different sort of organelles. In the cell itself. And essentially had to figure out, well, how do these things get instructions be made right? There must be something giving the cells instructions to make these proteins. That's the idea behind the target theories. There must be some sort of very important critical molecule that can be affected by radiation or by whatever it may be. To cause any sort of biological effect. And we've kind of just talked about why is DNA considered the primary critical. Part. If you have ionization or excitation, proton comes in. Ionization or excitation first. If it's ionized that particular atom, it will. Then go to a direct or indirect action to. Accept the macromolecule. Which is indirect. You get that free radical formation, right? It's direct. The macromolecule. Itself is getting ionized and the bonds are breaking and not working correctly. Powered by Notta.ai This is showing. What? Essentially a lot of experiments kind of come to the flu, that if you have radiation. Passed through a cell. But it's not interacting with the nucleus and with the DNA within the nucleus itself. Generally speaking, there's no effect. Let's just keep it simple like that. Theoretically, if it was close enough, but not quite. Hitting it again, you could have that indirect action, right? Where it moves a very small distance to interactive molecule. But generally speaking, if it's anywhere other than the nucleus, you don't have these sort of obvious biological effects occurring, all right? If it does hit the nucleus, if it does hit the DNA. Either gets chemical bond breakage and therefore damage. Or you get this chemical bond repair so it can repair itself. I mean, again, humans, animals, whatever. Evolve in the presence of constant radiation from, like we talked about last week, colonial radiation. Radiation, things like that. Right. So there are processes in the body to repair these, sort of any. Damage that's caused. The issue is when it doesn't repair correctly or when the repair function. The proteins that repaired are damaged. Or not working. All right. Bottom line for the radiation. To matter in a sense. Affect the cell. It has to hit within the nucleus. It has to hit the DNA in some capacity, whether it be some direct action or indirect action. Right. And it's not like radiation. Is trying to aim for the critical target. It's not like, it's like, oh. I know. I have to hit the nucleus. I have to hit the DNA. Radiation just exists, right? So. If it goes through, no problem. They can deposit synergy in the nucleus, in the DNA. Then we have some issues. Does that make sense? Okay, no question. If it hits the nucleus and damages the DNA, it could lead to cell death. Cell death can be described in. It's not always apoptosis where the cell explodes. Not explode, but essentially breaks apart. It could be. Some of their syneptic, where basically the cell loses its reproductive capability. That's a common endpoint. Is that for us to consider? A cell alive or viable, it has to be able to divide. So if it's still. Living, but it can't divide anymore. That's also potentially a cellular depth. Okay? Or could have some sort of denamutation. Maybe the cell survives, but it's at home. Maybe it's not creating proteins in exactly the right way. Those proteins are less effective. But the cell is still alive. If it's in a germ cell, right? Cells that pass. On. Dna to the progeny. Then there can be heritable or hereditary effects. Meaning that things that can be passed on. From generation to generation. Somatic cells, sole on the other cells. If it's affected, it could lead to cancer induction, and that doesn't necessarily mean. That you get exposed radiation, and then you have cancer. It could be something that is delayed or prolonged. For. 2030, 40 50 years. Okay. Any questions about that? All right, so we finished up radiation. How they interact. We started talking about how radiation effect your cells and how that chemistry of radiation by ourselves. By ourselves. For today reasons. Hired chapter two and review the DNA structure. So the more we're going to get into DNA structure. Powered by Notta.ai