 I want you to guess what is the energy in a chemical bond. And just to demonstrate this, I'm going to draw, I don't know, here's molecule A, this is just an atom. And I'm going to draw a chemical bond, does that work, with another molecule B. And what was a chemical bond? Remember, all we're doing is essentially we're sharing electrons between these two atoms. And in the act of sharing electrons, literally sticks them together. I want you to think about these two atoms like they are magnets. And go with me on this. I have a blue magnet and a yellow magnet. Wow, look, I have to make them like that in order to make a match up with my color except it's yellow and I'm whatever focus. Tell me this, imagine that the magnet, the stickiness of the magnet, would you agree that my two magnets are actually bonded together? Tell me, if I wanted to break the chemical bond between my two magnet molecules, am I going to have to put energy in to do that? Or do you think energy is going to be released to break these two apart? Grab some magnets, you can play with them if you'd like. Can you accept the fact that I actually have to apply energy? I have to flex my muscles a little bit. I have to use some of my gummy bear in order to break these guys apart. Do you agree with that? I'm going to write that down right now. If you break a chemical bond, you must put energy in. You have to use up some energy to break that chemical bond. Now, visualize this. If these really are two molecules, what's true about them? They're moving, they have their own kinetic energy and random molecular motion. Brownian motion means that eventually, if they come close enough to each other, do you agree that they're eventually going to come into each other's sticky space? That sounds kind of disturbing, but do you agree that, look, there's a point at which if they randomly get this close together, they will connect. They will form a chemical bond. Did I have to put in energy? Did I have to add any energy to them to make it happen? Assuming that they are moving, they're molecules. So they're already moving in random brownian motion. Did I have to add any energy? Absolutely not. So to form a chemical bond, energy is actually released. Think about that. If, and this is a bizarre little scenario, if I were to say stick a piece of paper right here, imagine a piece of paper on my little magnet, and then the random motion, the connection, the formation of the chemical bond would actually move my paper. Can you imagine that? If I move a piece of paper, I just didn't work on that piece of paper, and that means that there must have been energy available to do that work. Do you agree with that? Totally. So for me, I have to visualize my magnets, and I don't even have to think twice to go, yeah, it totally requires energy to break them apart. And then if it requires energy to break chemical bonds, then when they form, energy is going to be released. And the incredible thing is that you always have to break chemical bonds to form new ones. Some chemical bonds are super easy to break, and don't require a whole lot of energy. Others are super stable. And if you want to try to break that chemical bond, it's going to take some serious muscle to do it. It's going to take some serious energy input to make it happen. So these chemical bonds really want to form. And when they do, massive quantities of energy are released. Combine solid sodium. Oh my gosh, I got to go look for a video of this. I'm sure there's one online. Solid sodium, not sodium chloride. Just plain sodium. If you add sodium to water, the, I don't know, the desire to form a chemical bond between sodium and water molecules is so gigantic. They're like, they're so attracted to each other that this massive quantity of energy is released. Never combine elemental sodium with water, because it's like a bomb. We have just an incredibly massive release of energy, because chemical bonds are forming. We can, this is, this is clutch. This is key to understanding, okay, our whole process of getting energy out of our food. Where did it come from? How did we get it? You want to make sure you understand that breaking those chemical bonds requires some energy to do. Now, the energy, that is considered activation energy. That's why we have activation energy. And activation energy is basically a little bit of energy that you must put in in order to cause a chemical reaction to occur. And I need to tell you this now. Enzymes, this is, I mean, we're coming back. We're going to review this again and again and again. Enzymes lower activation energy. That means that an enzyme comes in and say the activation energy to make a chemical reaction occur is, I don't know, 10 calories. An enzyme comes in and says, hey dog, I got this. I'm going to lower the activation energy to one calorie. It's going to make it much easier for a chemical reaction to take place. That's why enzymes are incredible. They're proteins in our bodies. And it's why we need to treat them nicely. We better be nice to our enzymes. And we're going to see enzymes, holy enzymes this entire semester. There are some rules to moving energy around. If we're going to take the energy in a chemical bond and break it apart and form some new chemical bonds and release energy that we can then use to do work, there are some rules that we're going to have to follow. And those are the rules of thermodynamics. Be right back.