 Hello, everybody. I'm back with a very exciting lecture series on my second favorite molecule ever, DNA. My first favorite molecule ever has to continue to be ATP. ATP is totally related to DNA because ATP is a nucleic acid. It's like a fancy nucleotide. So hopefully some of this DNA conversation will feel a little bit familiar to you because of the background that you have with energy and ATP. But for the purpose of this next series, we're going to spend three lectures talking about DNA from a really molecular standpoint. And the first thing we're going to do is talk about the structure of DNA. And that leads us to, again, of these super powerful themes in biological sciences, structure determines function. So we're going to start out with the structure of DNA, and that will lead us to the function of DNA. And then we're going to look at all these really cool sort of biomolecular applications of what we learned about in these first two lectures. Before we go anywhere, DNA is a nucleic acid that codes for the building of proteins. I know we've said that before in this class, but put it in the memory box. Now it becomes the thing that you hang on to for context. Everything that we're going to learn, all the little crazy details are to support how DNA works, which is to build proteins. And proteins are literally everything that makes you who you are, your physical body, and your function, all the things that let you do what you do. Enzymes are proteins, skeletal muscles are proteins, hormones can be proteins, proteins are transporters and channels, proteins, they're found everywhere and they're the workhorses of our bodies, they're the workhorses of the cell. Having a strategy for keeping organized the instructions for building proteins, that's what DNA is doing. That's why we're here. I'm going to do, in this lecture, we're going to start with sort of a big overview of DNA through a life cycle. And so we're going to just spend a second looking at getting some vocabulary and looking at the human life cycle.