In this video, we're going to begin our lesson on DNA repair. It turns out that DNA replication is not always a perfect process. Most of the time, DNA replication works exactly as it's supposed to, but occasionally it will not work perfectly, and it will create errors. Base pairing errors can occur during DNA replication. For example, we know that adenines are normally supposed to be paired up with thymines. But if there's a base pairing error that occurs, then adenine might be base paired with cytosine instead of being base paired with thymine, as it's supposed to be. These base pairing errors can occur 1 out of every 100000 base pairs, which at first glance might seem like a really low error rate, only one error out of 100000 base pairs, but it's actually a relatively high error rate considering that there's a lot of DNA and DNA replication needs to occur often. Unrepaired errors can actually result in permanent mutations, and these permanent mutations in the DNA can lead to diseases like cancer.
In our example image below, we're showing you how these DNA errors can resemble typos in a resume. In this cartoon, a guy is coming in for an interview for a job position, and he hands his resume over to the big boss. The boss is reading through the resume and says, "It says here that you're a professional booger." The guy tries to clear it up, saying, "Oops, I meant blogger." That typo in the resume is going to greatly affect this guy's chances of landing the job position. Mutations, these unrepaired errors in the DNA, resemble typos in a resume and can significantly change the end result of the product that's supposed to be encoded by the DNA. These unrepaired errors or mutations can lead to diseases like cancer.
This here concludes our brief introduction to DNA repair, and we'll be able to talk a little bit more as we move forward in our course. So I'll see you in our next video.