Transcription
So I'm going to spend a few minutes here talking about energy. And energy is a pretty difficult subject to grasp. I can't really, like, hold up my hands and say, "Here's some energy. This is what it looks like." It's very hard to describe because you can't really do that with energy. In a physics sense, we say that energy is the capacity of something to do work, to move something around or do work. And that also is very hard to really grasp or understand what it means.
And so instead of trying to do that, what we're going to do here is talk about different types of energy. So energy can exist as different forms. And if we can understand the different forms of energy, then we can sort of start thinking a little bit more broadly about how they all interconnect.
So on this slide, I have a list of, um, different types of energy. And this "E" is the same all the way down, right? So these are all energies. The "E" here is that is standing for energy. Um, and but there's different types of energy here. And we've given them the name, uh, by like putting a little subtext down here. So this is E thermal. Thermal is a fancy word for heat. Sometimes we would call this E heat. And this is talking about the energy that is found in things that are warmed up or that are warmer than they were when they were cold. So thermal energy is the energy that's associated with something being warm.
Light is light energy, like these, um, photons that are are coming from us from the sun. The sun is spitting out energy all the time, and it's spinning out in the form of these photons, which are little package packages of energy. And, uh, we detect that as light.
And then also sound also is a form of energy. And if you've ever turned up a speaker really, really high, like crank it up to 10 or 11, you can see the speaker like moving. And so that's the sort of energy there.
Now, all these three, thermal energy or heat energy, light, and sound, these are all basically forms of movement. So thermal energy, we said that when something gets hotter, it starts to move faster. The particles vibrate or move quicker and more. So this is movement. Light is also a type of movement. We talk about the speed of light. Light is traveling fast. And then finally, we have sound, which is also movement because you can see the vibrations of a speaker. So these are all energy that's associated with moving. And, um, we a fancy word for moving is kinetic. So if you've ever heard of kinetic energy, it's really, um, what that's saying is the energy of things that are moving. So kinetic energy, thermal energy, heat energy, light energy, and sound energy are all forms of kinetic energy. Let me write that further up.
All right. So we also have, um, two other forms of energy written down here: the energy of a gradient and chemical energy. And these energies are more than not to do to do with movement. They're to do with energy that's stored away. Um, it can be released at any point, but it's not necessarily like something actually physically moving around. And so we call these, this is a form of potential energy because it has the potential to do something, but it's not doing something right now. It's kind of stored in there. We don't see it bopping around and moving, but it could potentially do that if it was to be released. So gradient energy and chemical energy are potential energies.
Now, what is gradient energy and what is chemical energy? The next couple of slides are going to explain that for you.
So first of all, let's talk about gradient energy. In this slide here, you can see there's a mixture of two substances. There's the single yellow circles, and they're pretty evenly spread through these three regions. And then there's this other substance here that is a like a twofer, like a double, that it's a different molecule, right? They're mixed together. And if we were to look at how these are spread out and count how many of these, um, this substance is in each area, uh, there's what, one, two, three, four, five of them here, maybe six. There's one, two, three, four, five, six, seven, eight, nine of them here. And there's one, two, three, four, five, six, seven, eight, nine, right, twelve of them here. So clearly, there is more of them up here and less of them down here. And that's what this triangle, this gradient triangle is representing for you. It's one of my concentration triangles. It shows you that there's lots of this molecule up here and fewer of this molecule, oops, fewer of this molecule down here.
And we've also learned a little bit in the last unit about diffusion. And we learned that when you have something with a lot of it in one place and not very much of it in another place, it's going to want to spread. And so these molecules here are going to want to move this direction and spread out. So after a period of time, there'll be an even number of these spread right through here. So there's there is a desire, kind of, or a propensity for these this these molecules to spread down this slide. And that's what we mean by gradient energy. If I was to put like a barrier across here, these molecules would want to get through, and they can. But if I put a little opening in it, like my middle opening, uh, right here, then they would like stream through to even out the concentration. And that desire of them to move from point A at the top to point B at the bottom is kind of like an energy. And it's stored up in there right now because they're not spaced out evenly. And they're potentially, there's a barrier to stop them. But the desire for them to move is there. And so they have a potential to want to move from area A to area B, from higher concentration to lower concentration. So that's gradient energy.
Lastly, we have kinetic, the chemical energy. So hold on, let me find the right slide here. Uh, so chemical energy is any of the energy found. I'm sorry, chemical energy is any of the energy that is found in chemical bonds. So anytime you have chemical bonds, like for example, let me draw a molecule of water. There's a chemical bond here, a covalent bond, right there. And there's a covalent bond right there. And this bond represents energy. There's energy stored in this bond, and there's energy stored in this bond too. And anytime you have a molecule with bonds, there's energy stored in it.
If I was going to draw alcohol, which is ethanol, looks like this. And there's H's here. Every single one of these bonds, and the bonds are the sticks that I've drawn. So there's a bond right here, and a bond right here, and a bond right here, and a bond right here. Every single one of these bonds represents energy trapped in that molecule. And you can release that energy potentially if you were to break those bonds, separate those, uh, break that bond and separate these two atoms. Um, it's kind of almost, it's like what happens when you put gasoline in your car. Gasoline is a molecule. It's a molecule that looks like this. It's got eight carbons in a row: one, two, three, four, five, six, seven, eight. And it's got lots of H's. It's mainly a hydrocarbon. Gasoline. All these are H's. I'm not gonna draw them all in, but all right. So there's all these H's. And you put this in your car, in your gas tank, and in your, um, engine, in the combustion chamber of your engine of your car, these bonds are systematically broken, broken, broken, broken, broken. And the result gets squirted out your tailpipe. And as those bones are broken, the energy is released. And it's used to drive all the pistons and everything up and down in your car and make your wheels turn around. So you're basically releasing the chemical energy that's stored in the gasoline molecule in the combustion engine in your car. And then the energy is used to push your car forward.
All right. So anytime you got a molecule, there's energy stored in it. Molecular protein, there's energy stored in it. Molecular carbs, there's energy stored in it. And that's why there's energy in your food. That's why there's calories in your food. Calorie is a measurement of energy. So when we eat carbs, we get a certain amount of energy. We get calories from the bonds that are holding those carbohydrate molecules together. And in your body, you break those bones apart. We're going to dig into that later in the rest of this unit.