Nucleic Acids

in this video, we're going to begin our lesson on new click acids. And so nucleic acids we know are one of the major classes of bio molecule polymers, and it turns out that nucleic acids can have a variety of different types of functions. However, in our biology course, we're going to focus on the primary function of nucleic acids, which is really to store and encode genetic information or information that could be passed down from one generation down to the next generation of life and so an example of a nuclear gas. It is, of course, d n A. And so we'll get to talk more about DNA as we move forward in our course. But another example of a nucleic acid is also R N A as well, and once again, we'll get to talk more about DNA and RNA as we move forward in our class. Now, the monomers, or the building blocks that are used to build new clay ic acid polymers are referred to as nucleotides, and so you can see that there is a resemblance between new click acids and nucleotides. Just by looking at the first few letters here, the new CLee prefix here, and so that could be helpful to keep in mind. Now, nucleic acid polymers similar to proteins, have directionality in their chain, meaning that one end of the chain will be chemically different than the other end of the chain. However, when it comes to new Clegg acid polymers, the directionality is indicated with a five prime and and a three prime end and moving forward. In our course, we'll get to talk Maura about the directionality and the difference between the five prime and three prime ends. But for now, we just need to know that there is directionality and it's indicated with a five prime and three prime end. Yeah, so let's take a look at our example down below at the formation of nucleic acids from nucleotide monomers. And so, looking at this image notice on the far left, we have thes separate individual building blocks or monomers of nucleotides so we can label these as nucleotide monomers, and so notice that their separate and individual pieces here. But if we wanted to combine these separate pieces thes separate nucleotides and link them together into a chain like what we see over here on the right. Then we're building ourselves a nuke Laich acid polymer, for example, a DNA polymer. Now, once again, it's also important to note that nucleic acid polymers they have directionality, which means one end of the chain is gonna be chemically different than the other end of the chain. And so we refer to this directionality as we mentioned up above as the five prime in the three prime ends. And so we could go ahead and put the five prime and over here and the three prime end over here. And once again, we'll get to talk, Maura about the five prime and the three prime ends and exactly what they're referring to as we move forward in our course. But for now, this here concludes our introduction to nucleic acids, and we'll get to talk more about them as we move forward. So I'll see you all in our next video

in this video, we're going to talk a little bit more about nucleotides. And so we already know from our last lesson video that nucleotides are the monomers of new click acids. But really, just one single nucleotide monomer consists of three different components that we have number down below here in our text and also noticed that we have the three components color coordinated with these backgrounds, where the first component as a pink background, the second component as a blue background and the third component has a yellow background, and these background colors correspond with the colors that you see down below in our image. And so the very first component of a nucleotide monomer is a phosphate group which, recall from our previous lesson videos, is just a functional group that looks like this down below with a phosphorus atom in the middle. Now, the second component of a nucleotide monomer is a pen, tose, sugar and all. The pintos part, it means, is that this sugar has a five member ring, and so when we take a look at the blue component down below, noticed that there is a ring and the ring has a total of five, uh, members in it, and so that makes us a pento sugar. And then the third and final component of a nucleotide monomer is a nitrogenous base. And so it turns out that the nitrogenous space can vary and there are five different types of nitrogenous bases. And we'll talk more about those five different types of nitrogenous bases and our next lesson video. But for now, taking a look down below, we can see the third component is here in yellow, the nitrogenous base. So in our last lesson video, we were abbreviating nucleotides, using symbols that looks somewhat like this in the corner. But really just one of these nucleotide monomers that we see here in the corner consists of three components. Once again the phosphate group here, the sugar component here and the nitrogenous base up here. And so you can think that this little nucleotide consists of these three components, like what you see here Now this leads us to different types of nucleotides. There are d n a nucleotides or D oxy ribonucleic acid nucleotides. So DNA is the abbreviation for the molecule called D oxy ribonucleic acid on. Then there are also ribonucleic acid nucleotides or R n a nucleotides. And so the DNA and the RNA nucleotides they use different sugars amongst also sometimes using different nitrogenous bases, which will talk more about as we move forward in our course. But if we take a look at our image down below, notice that we're comparing DNA nucleotides versus are in a nucleotides. So the left half of our image over here is specifically for the d n a nucleotide and the right half of our image over here specifically for the r n A nucleotides. So notice that both nucleotides have three components that we talked about before the pink component here, which is the phosphate group. Uh, this one also has a phosphate group, the RNA nuclear type. They both also have a pen tose sugar on dso. You can see that the blue part is here, and then they both also have nitrogenous bases. Now, here's specifically we've said that the nucleotides of DNA and RNA use different sugar. So we're gonna focus in on the blue part here and over here and notice that, uh, the RNA over here on the right, uh, it uses a ribose sugar whereas the DNA over here on the left uses a d oxy ribose sugar. And so the D oxy part here means one less oxygen. Oxy means oxygen and d means without. So the deoxyribonucleic sugar has one less oxygen in comparison to the ribose sugar over here. And so what this means is that the ribose sugar is gonna have a hydroxyl group in O H group at this position, and the deoxyribonucleic over here is not gonna have the extra oxygen is just gonna have a hydrogen here. And so the d Oxy Ribas has one less oxygen. Comparing this position to this position over here. And so we'll get to talk Maura about DNA and RNA as we move forward in our course. But again, one of the biggest difference is is that they use different sugars. Uh, DNA uses deoxyribonucleic sugar, and Arna uses ribose sugar. So this year concludes our introduction to nucleotides, and we'll be able to get some practice applying these concepts as we move forward in our course. So I'll see you in our next video

All right. So here we have an example Problem that's asking What is the difference between the sugar group and DNA and the sugar group in RNA? And we've got these five potential answer options down below. Now, after reading through each of these five potential answer options, there's one that we can eliminate right off the bet. And that is gonna be Option E, which says the Sugar group of DNA and RNA are not different. Of course, we know that this is false, that DNA and RNA. They have different sugar groups from our last lesson video. Now Option A here says the sugar group and DNA has a hex owes, while the sugar group in RNA is a pen tose now. Ah, heck, so's we did not mention at all in our last lesson video. We only talked about penthouses and recall. Penthouses are sugars with a five member rink, whereas heck sauces are sugars with the six member drink. But we didn't mention anything about hexes in our last lesson video, and this is simply not true option. It is not true, and both DNA and RNA used a pantos sugar now Option B says the Sugar group and DNA has an extra hydroxyl group than the sugar group in our DNA. Now recall. Hydroxyl groups are O H groups, so they have an oxygen in them and recall that DNA stands for D, oxy, ribose and D oxy means one less oxygen. And so if DNA had an extra hydroxyl group, that would mean it would have an extra oxygen. But that is not the case with DNA. It is D Oxy, so that means it has one less, not one extra hydroxyl group. And so, for that reason, we could go ahead and eliminate answer Option B. And then, of course, looking at answer. Option C here says the sugar group and DNA has one less hydroxyl group than the sugar group in RNA. And then, of course, this is going to match up with what we were just talking about, and this is going to be the correct answer here for this example. Problem now, Option D here says the Sugar group and DNA contains one less Carbonnel group than the sugar group in RNA. But the Carbonnel Group is not the right functional group here. Remember, Carbonnel groups are see double bond oh, groups. But we're looking at the hydroxyl group, not the Carbonnel groups. That's why option D is incorrect. And so, once again, option. See, here is the correct answer for this example problem. And if we were to take a look at our last lesson video here, we can see that the DNA nucleotide over here has one less oxygen in comparison to the ribose, which has an extra oxygen atom. And so the D Oxy, therefore, has one less hydroxyl group relative to the ribose, which has one additional hydroxyl group. And so that concludes this video, and I'll see you all in our next one.

So now that we know that one of the components of a single nucleotide monomer is the nitrogenous base in this video, we're gonna focus on the five nitrogenous bases. And so once again, there are five different nitrogenous bases, and these five nitrogenous bases can be grouped together as either pi remedies or as pure ins. And so the pie remedies are single ringed molecules, whereas the pure ings are double ringed molecules. And so, if we take a look at our image down below over here on the left hand side, notice that we're showing you the nitrogenous bases which can once again be grouped into these two groups. The pie remedies which we have over here on the left hand side, and the pure ings which we have over here on the right hand side and notice that the pie remedies, as we mentioned up above, are all single ringed molecules, so they only have one single ring, whereas the pure ings over here are all double ringed molecules. So they all have two rings. Like what we see here now. Also, these air called nitrogenous bases for a reason because they have plenty of nitrogen atoms as you can see, what I'm highlighting right here. All of these nitrogen atoms makes these bases pretty nitrogenous, and that's why we call them nitrogenous bases. Now it's also important to note that each of these nitrogenous bases has a name. And so you can see we have cytosine timing and you're so are the pie remedies. And then we have adding and guanine as the pure ings. And so notice that each of these nitrogenous bases names has a unique first letter. And so, for instance, side of scenes See, here it's first letter is unique. First letter. It's the only one that starts with a C and so we can use the first letter C to abbreviate side of scene now. I mean, it's unique. First letter is t yourselves unique. First letter is you. Adnan's unique first letter is a and guanine is unique. First letter is she And so we can abbreviate these, uh, nitrogenous bases just by using the one letter. Now notice that when we introduced by remedies up above that, we made the why here in pi remedies interactive for you guys to fill out yourselves as you watch this video and the reason that we're emphasizing this. Why here is because notice that most of the pie remedies which have a Y in it also have a y in them themselves. So sido scene and thigh mean have wise in them which make them pie remedies and notice that the pure ings such as adding and guan ing they do not have a Y in them. And so they're gonna be batch over here. And really the Onley exception to this. Why is gonna be the euro sell your cell is a pie remedying even though it doesn't have a why. But if you could just remember this one exception, then that will help you batch these nitrogenous bases into the correct groups Now, which will also notice is down below the image. We have this memory tools to also help you group and batch these, uh, nitrogenous bases. So when you think of pie remedying that kind of sounds like pyramids. And when you think about pyramids, you think about the Egyptian pyramids. And of course, we all know that underneath the Egyptian pyramids there are creepy tombs under those pyramids. And so here we have an image of the creepy tombs under the Egyptian pyramids. And so you can think that, uh, the sea and creepy is for the C inside of seen. The tea and tombs is for the tea and timing and, of course, the U and unders for the you and you're a cell. And so, by remembering pie remedies thinking about pyramids, you'll think about the creepy tombs under the pyramids and you'll be able to group these nitrogenous spaces. No problem. Now, on the other hand, the pure ings. On the other hand, all you gotta do is think about pure as gold. So here we've got this guy has got some gold in his hand and he's thinking pure is gold. And so what you can see here is that the A and as is for the A and add Ning. And of course, the G and gold here is for the G and guanine. And so, by remembering that periods are pure as gold, you'll be ableto determined. These, uh, adding and guanine are appearing. No problem now. Another important thing to note here is that timing is a nitrogenous base that is uniquely Onley found in D N A. Whereas you're So on the other hand is a nitrogenous base that is uniquely found Onley in our DNA. And so in our DNA structure, what we'll see is that all of the teas are gonna be replaced with use. And so use once again our specific for Onley in RNA, whereas tease air specific for Onley in DNA. So that's an easy way for us to be able to identify if a strand is DNA or RNA just by looking to see if teas or used are being used. Now this leads us to talk a little bit about DNA structure here because in DNA structure, the nitrogenous bases on different DNA strands are going to base pair together. And so the base pairing works in this fashion, where Adnan's or a czar always going to pair with thigh means or teas and side of scenes or seas are always going to pair with guanine or G's. And so what you can see is that a pure ing is always going to be paired up with a pie remedy. Eso A's pair with teas and then once again, uh, the pyre emitting of citizen is always gonna be paired up with a guanine or I'm sorry, appearing of guanine. So they always pair a pyre emitting with appearing. Now, if we take a look at the image over here on the right hand side, notice that it's focusing in on DNA base pairing and so DNA is made up of two strands on DSO. What you'll see is that there's one strand over here on the left and there is another strand over here on the right and these two strands, they connect to each other via, uh, interactions between the base pairs where once again a always pairs with t and C always pair with G. So notice that the A over here on this strand is always gonna pair with tease on this strand and vice versa. And the seas on this strand are always gonna pair with the GS on this strand over here and vice versa. And so once again, add means will always pair with findings and sido scenes will always pair with guanine. It's and so this is really important to note here. And so this year really concludes our introduction to the five nitrogenous bases and we'll be able to get some practice applying these concepts as we move forward. So I'll see you all in our next video

All right. So here we have an example problem that wants us to complete the blank here, using one of these six potential answer options down below And the example problem says the puree nitrogenous bases are blank. And so, of course, if we recall from our last lesson video that one of the ways we can use to help us remember the puree nitrogenous bases is to remember pure ing are pure as gold. And so, by remembering pure as gold, we can see that the A in the as is for Adnan and the G and the gold is for guanine. And so adding and guanine are the pure Eanes. And so, of course, when we look at the answer options, we could see the option, he says, adding and guanine. And so that is going to be the correct answer for this example. Problem and all of the other ones are incorrect. And so that concludes this example problem. And I'll see you all in our next video

in this video, we're going to talk about the formation and the breakdown of new Clague acids. And so recall from our previous lesson videos that if we want to build a polymer, then we're going to need a dehydration synthesis reaction. And so dehydration synthesis reactions are going to link individual and separate nucleotides together so that they can begin to build the new click acid polymer. Now, the Covalin bonds that link these nucleotides together are specifically referred to as Foss. Phone Die Esther Bonds and notice that we have this yellow background behind the facade Iast or bonds in the text. And that's because it links to the yellow color that we have down below and our image, which will be able to see that here shortly. Now the formation of phosphor, odious or bonds between nucleotides is going to result in the sugar phosphate backbone of the nucleic acid, and the nucleic acid backbone is going to have directionality, as we already indicated in our previous lesson videos. So we know that there's going to be a five prime end and a three prime end now here were specifically indicating that the five prime end is going to be the phosphate group end the free phosphate group, which will be able to see down below. And the three prime end is going to be the free hydroxyl group, the hydroxyl end. So let's take a look at our image down below to start to clear some of this up. So we're looking at fossil a dinosaur bond formation. And so notice on the far left hand side, we're showing you two separate nucleotide monomers here. We're showing you a sight unseen. And here we're showing you a thigh mean and which will also notice is that these are specifically deoxyribonucleic tides or DNA nucleotides. Because this position here is not containing a hydroxyl group, it has one less oxygen d oxy. And so these are DNA nucleotides and noticed that their separate over here on. So if we want to join them together so that we can start toe build a polymer DNA polymer uh, then we're going to need the dehydration synthesis reaction, which we know is used to build up polymers and the dehydration synthesis dehydrates the molecule, releasing a water molecule on, and it synthesizes a larger molecule in the process. And so notice that over here these two nucleotides are joined together via this bond that we have highlighted in yellow. And this is specifically referring to the phosphor. Oh, digester bond. And so, which will note is that there is a sugar phosphate backbone that has been formed here, where we have alternating sugar and then phosphate and then sugar and then phosphate. And so this is what we call the sugar phosphate backbone and branching off of the sugar phosphate backbone. We have the nitrogenous basis. And so once again, this sugar phosphate backbone has directionality. It has a five prime end and a three prime end. The five prime in is going to be the phosphate group end the and that has the free phosphate group. So when we take a look at our image down below, notice that the free phosphate group is over here on this end and so this will be the five prime and for that reason and then, of course, the three prime and it's gonna be the end has the free hydroxyl group. And so taking a look down below here notice that there's a hydroxyl group at this end, the opposite end And so this is going to be the three prime hydroxy will end. And so this year really concludes our introduction to the formation in the breakdown of nucleic acid polymers, and we'll be able to get some practice applying the concepts that we've learned here as we move forward in our course. So I'll see you all in our next video.

in this video, we're going to briefly compare and contrast DNA and RNA. And so recall that D. N A is really just an abbreviation for deoxyribonucleic acid and DNA. Its primary function is to store genetic or hereditary information inside of the cell. And so this is information that would be passed down from one generation down to the next generation. Now we'll talk more about the functions of DNA later in our course, and in this video, we're mainly gonna focus on the structure of DNA and DNA forms, a structure that scientists refer to as a double helix. And so they call it a double helix because DNA is really going to be made up of two strands. And those two strands form a helix, a twisting, winding ladder type of structure that will be able to see down below in our image. And these two strands that make up the DNA molecule um, they're actually anti parallel with respect to each other, and anti parallel just means that the directionality are going in opposite directions. These two strands go in opposite directions in terms of their directionality, and we'll be able to see the the anti parallel Shands as well. Down below in our image. And these two strands, these two anti parallel strands, they're actually connected to each other via hydrogen bonds that form between the nitrogenous base pairs. And so once again, we'll be able to see this down below in our image. So on the left hand side of our image over here, notice that we're showing you d n a deoxyribonucleic acid, and once again, DNA forms a double helix structure. And so that means that it forms, uh, has two strands, so you can see one strand is right here, and the other strand is right here. And these two strands, they wind up onto each other, forming hydrogen bonds between the base pairs. And so, if we were to unwind the DNA so that it has this type of structure down below once again you'll see the DNA base pairs where, uh, sees always pair with G s and A's always pair with teas and so you can see the color coordination here and see how they always pair in that fashion. On DSO This here represents one DNA strand, and, uh, this down here represents the other DNA strand and so you can see that this blue structure that you see here represents the sugar phosphate backbone. And we know from our last lesson video that sugar, phosphate, backbones of nucleic acids have directionality. And so notice that this end of the sugar phosphate backbone for the Strand is the five prime. And which means that the opposite end over here is going to be the three prime end. And so it's going from five prime to three prime left from left to right in that direction. However, notice that the opposite strand over here it's five. Prime end is over here on the right, and so that, of course, means that it's three. Prime end must be over here on the left, and so the bottom strand is going from five prime to three, prime from right toe left in the opposite direction as the top strand. And so because we have two strands that are going in opposite directions, that makes these two strands in the DNA molecule anti parallel with respect to each other. If they were going in the same direction, that would make them parallel, but because they're going in opposite directions. That makes them anti parallel. Now, on the other hand, are N A is the abbreviation for ribonucleic acid, and Arna turns out it has a variety of different types of functions. And once again, we'll talk more about the functions of Varna later in our course. But one of the primary functions of RNA is to act as a template for synthesizing or building proteins. Now, in terms of the structure of RNA, aren't a usually forms a single stranded nucleotide change rather than forming a double helix like DNA. So if we take a look at our image over here on the right hand side, notice that we're showing you r N a, which once again is usually a single stranded structure, so you could see the single strand of RNA right here. And, of course, the single stranded RNA is gonna have a sugar phosphate backbone that has directionality. And so if this is the three prime end over here, that means the opposite end must be the five prime end. And so you can see that RNA once again, it's specifically gonna be using nitrogenous bases of use instead of using the nitrogenous bases of teas like DNA so T is once again specific for DNA, whereas use a specific for our specific for RNA and the once again, ARN is normally a single stranded structure. But the base pairing here can still apply if it binds to um itself. Sometimes the Arnie can fold up onto itself and buying to itself. Forming these complex structures, Um, and also are they can, sometimes buying two small antique Oden's, which again we'll talk a lot more about later in our course. But you can see that this is how the Arna would base pair in the same way as DNA, except once again replacing the tea with the you. And that's really the main take away. And so this year concludes our introduction to the differences between DNA and RNA, and we'll be able to get some practice applying these concepts as we move forward in our course. So I'll see you all in our next video