Open course ware

BARBARA IMPERIALI: So what we're going to do today is we're going to finish up a bit of transcription, and then I'm going to talk largely about transcription control. Because it's tremendously important that we actually not just know how to transcribe, but we know how it's controlled, and how ultimately the appropriate messenger RNA is sent out for a translation into proteins. So transcription control is a very important component. So let me just start with this first. So these are typical of questions. And they look like, gosh, I don't have enough information to answer this question. And it's basically about what's known as the transcription bubble, which is the portion of the double-stranded DNA, where transcription is occurring. And so a transiently, the double-stranded DNA is opened up for the RNA polymerase, which remember has inbuilt helicase activity to start transcribing the gene. So let's just say we have the information we mig...

BARBARA IMPERIALI: OK, we'll get started. I've got everything turned on here. So, a couple of things. I've been mentioning that it's really kind of cool, I think, at this stage, where you've gathered enough steam in some of the topics that many things that come out in the news might start looking of interest or relevant to you. And I found this. It had a news brief in The Scientist, and then I went to the original paper, which is in Nature Biotechnology. And if you recall, towards the end of the work on proteins, we were talking about phenylketonuria, which is a genetically linked disorder, where people cannot metabolize phenylalanine to keep the levels of fell phenylalanine in check. So what happens is the phenylalanine gets converted to a toxic material, and it causes a lot of fundamental physiologic disorders that are a lot of neurologic disorders. So what a small company in the area called-- what's the name of the company? I can see it here. An...

BARBARA IMPERIALI: So we're going to get started. This is a complicated lecture to choreograph, but I'm going to do my very, very best because I think there's some pretty amazing stuff that we have to explain that is carried out in nature. And one of those things is how do we replicate the entire genome of organisms in one fell swoop almost perfectly-- sometimes there are little errors-- and fast. So we're going to refer to these numbers in a moment. But first of all, I just want to get you back in the picture of where we were at the end of the last section, the biochemistry section. And in the next few classes we're going to address issues related to the central dogma and the use of nucleic acids for information storage and information transfer. And before I do that, I just want to highlight a couple of things, just some terms that you should recall and recap from the biochemistry section about nucleic acids. So nucleic acids form complementary double...