Why was the discovery of the structure of DNA such a big deal? Knowing the structure led to the realisation that DNA is transmitting information, that it is the genetic material. Deoxyribonucleic acid or DNA, and ribonucleic acid or RNA are molecules that transmitted information. DNA is made up of building blocks or base pairs including Adenine, A, Thymine T, Guanine G, and Cytosine, C. What does this have to do with how information is transmitted over time though? So let's try analogy with the Biology Everywhere book. The entire book is written using an alphabet containing 262 letters joined together in different ways. How the letters are combined represents stored information that you read and understand. DNA is instead based on an alphabet of four letters, the ATGC, and use in the same way to communicate information to the molecular machinery in the cells that can read, understand, and act on an information. More than a minute, biology a rare book is packaged into pages and chapters to be more digestible, and DNA is packaged as well. Also to make it more digestible, it's wound under proteins called histones, and larger pieces of DNA are organized in the chromosomes. On DNA, their specific genes that code for particular proteins are RNA sequences that do some kind of function in the cell. Sometimes DNA is more or less accessible depending on how tightly it is wound. Think of it like how your closet is organised. Things that you need more regularly are also the ones that are more accessible. DNA is organised the same way in ourselves, ourselves organised instructions for making the proteins that we use all the time so that it's very readily available. Things that we do not use that often are hidden away. Accessibility of DNA and molecular processes influence how easily genes are accessed and therefore how easily they're expressed. And the study of that is a relatively new field called epigenetics. And we'll return to epigenetics at the end of this module. If you remember from course one there are four different kinds of macromolecules. We have our carbohydrates or carbs for short, for fats, proteins [BLANK AUDIO] And finally nucleic acids. So if you remember, proteins are the work assistance of the cell, and nucleic acids are storing information. So what's called the central dogma of biology? Central dogma is this idea that we have DNA, which is our master blueprint that has all of that information. We can make copies of that with RNA. And then we can use that information to make new proteins, which again, are the workhorses of ourselves. With the semi molecular biologists that you talk to, will actually tell you that this guy's most important RNA is a much larger role than we really give a credit for. DNA gets transcribed to make RNA. So a protein goes through and it looks at DNA, just think of DNA as a recipe book. So we'll draw a picture of a large recipe book right here, recipes has all the information. So let's say you want to just make one recipe you don't carry around your recipe book, you're going to write down in your recipe card. And so to get from here to here is a process called transcription. You make an RNA copy of what you need. You don't haul a cookbook around, you just haul a small piece of RNA around. And then that RNA is then translated to make protein. So just like you might take something that's in German and translated into English, we're taking language of nucleic acids and we're translating it into the language of proteins. So we're going from ATCG, which is the language of nucleic acids, and changing it into the language of proteins, which is an amino acids. Remember amino acids are the building blocks of proteins. And then once we've built the strands of proteins, they can fold up and then do the final work. So to reveal the central dogma describes the relationship between DNA, RNA and protein, and how we go from the language of nucleic acids here to the language of proteins on this side. So how we go from a recipe here, so the DNA or genome contains all the information that you need to RNA is like a single recipe card, and the protein is what we finally end up with. So this is whatever you're cooking for dinner for example. Okay, so how are DNA and RNA proteins related to one another?
