 Just you write down next point I will draw the structure you will understand this write down next line nucleosides are Nucleosides are n glycosides of pure of purine nucleosides are and Glycosides sites of purine or Pyrimidine bases with pentose sugar So this is the definition of nucleoside Pentose sugar What are nucleosides? We have a pentose sugar and that is linked with purine or pyrimidine base with n glycosidic linkage Okay, so what do you mean by this n glycosidic linkage? Suppose if I draw the structure of sugar here, which is this This is a structure of sugar. I won't draw the entire thing here Right, so we have all these bonds present OH etch you can put it on here CH2 OH like this we have here and this carbon this C1 actually it is attached with the base Like this nitrogen and then the ring we have like this Okay write down here base and base so this link is what this link is the n glycosidic bond and glycosidic bond So these are nucleosides actually so when you take adenine as a base the nucleoside is adenoside So with base what is the name of nucleoside? We have I'll write down here base one side and The name of nucleoside This side so if the base is adenine Nucleoside is adenoside if the base is guanine nucleoside is Guano sign Cytosine It's citidine thymine thymidine Uracil it is uredine So the point is this reference compound is pentose only this is not going to change But base can be changed If the base is this Corresponding nucleoside is this the name I have written similarly Nucleotides are what the last thing here we discuss Is nucleotides Okay, a structure of DNA is a double helix structure that you can go through Okay structure of DNA others then skip out the word. Okay Okay, so this is nucleosides you should know Next we'll discuss is all of you have written this Yeah, okay similarly nucleosides like I discussed it is it is the you know The combination of purine or pyrimidine base with pentose sugar and this base and sugar is connected with and glycosidic linkage nucleosides is this similarly nucleotides also we can define Okay, so what is nucleotide? write down nucleotide is a phosphate ester of nucleosides a nucleotide is a phosphate ester of nucleoside Which contains a purine or pyrimidine base? which contains a Purine or pyrimidine base with five Like this purine and pyrimidine base with a sugar With a sugar contains five carbon atom. Okay, one thing I'll repeat here In the last page That this structure is This structure is a base. It is not the actual structure I have just drawn this to make you understand what is n glycosidic bond Suppose adenine base you are taking so here we have the structure of adenine Gouonide then the structure of Gouonide. So this is just a base Where this n bond is joined with this carbon. So it is not any you know Correct structure is this it is not a correct structure because we have two nitrogen present in that in all these if you see That's what the meaning of this. Anyways, so next thing is what this? nucleotides like I said it has one base right, purine or pyrimidine base plus five-membered sugar plus phosphate phosphate and then It forms nucleotide Okay, if I draw the structure here of a nucleotide The structure will be like this Okay See one carbon We have hydrogen here and This contains one Like I said one base. So this is the base. I am using here double bond O Here we have double bond here. We have double bond and here we have NH2 So this is one base we have connected with C1 OH H. This is the sugar we have pentose So OH H and here we have H CH2 OH we have in general, but it is connected with a phosphate. Okay, so this point It is linked with a phosphate ion, which is P double bond O O minus single bond O minus so phosphate Sugar five-membered ring and a base this thing is nucleotides Okay, so base is there. This one is sugar and this one is phosphate They won't ask you the structure. You should know the definitions of nucleotides. However, this is also not that much important Okay, one note you write down nucleotides are linked together Nucleotides are linked together by phosphodiester linkage phosphodiester linkage between Fifth and third carbon atom of pentose sugar. Okay, this is the last thing you have to keep in mind a structure also you can draw To fast foot group you have to attach at fifth and third carbon Okay on pentose sugar like you see here. We have this group attached here Okay, one more if you attach this side Okay, this gives you phosphodiester linkage here the same this group present at this carbon third carbon This is third and this is fifth carbon. So this is the no Way the nucleotides are linked together. This is one nucleotide molecule At this point the another nucleotides are linked Okay, so like that you get a very You know big complex structure and CRT. I don't know whether it is given or not this structure But all these things you don't have to draw You should know the key points that I've given you that nucleotides are linked together by fast for diester linkage This term is important phosphodiester linkage between third and fifth carbon. Okay, so this is it after this We have function of DNA and RNA, which is not required, but I'll suggest you to go through once Through NCRT that is more than enough. Okay Yes Nothing is there. Okay So What we do next we have half an hour more. Tell me Any doubt you have no doubt one question you solve them One last question we will finish it early today Not from this some other things you see Did you write the test yesterday? There's cave pages. Yes or no Yeah, one question was there let me give you that question, which so there was this one question as to Friedelcraft's alkylation what it means What? It said there was this question in that test said Friedelcraft's alkylation is and then four options What are aromatic nucleus and Do you have that question now You have your phone with you right now all of you. Okay, let it be I'll Write down the question here. See the question is 2.52 gram 2.52 gram hydrated oxalic acid hydrated oxalic acid is oxalic acid which with two H2O hydrated oxalic acid Was dissolved in dissolved in 100 ml of water 100 ml of H2O 10 ml of this solution 10 ml of this solution Was diluted to diluted to 500 ml find normality of the final solution normality And the amount of oxalic acid oxalic acid Present in the final solution Do this What is the answer you got Shreya? Uh that 0.08 thing Did you get the uh option right? Yeah Oh Do it now Shreya the question is The question is there dehydrated. Okay, but with dehydrated it means the uh molecular mass should be what? 63 Should be 19 right Dehydrated means what I have given your hydrated oxalic acid Okay, I did not check this because uh the solution was given over there, no The solution the molecular mass they have taken as 126 correct? Yeah 126 But in the question they have given dehydrated So when it's dehydrated it means the mass molecular mass should be what 90? Oh, I switched both sir by mistake. That's how I was getting the answer Yeah, so when you get this dehydrated oxalic acid if you take Okay, then the answer will be something else it is not there in the option Okay Answer is something else which is not given in the option So you try this Hydrated means molecular mass is this Number of equivalents Will be what? mass divided by equivalent mass 2.52 divided by equivalent mass e So equivalent mass of oxalic acid is what? If it is hydrated I am going through the option so through the solution which is given Okay Taking this as hydrated 2.52 divided by 126 divided by 2 n factor is 2 for oxalic acid Okay This you will get this by 63 that will be 0.04 Yes or no 0.08 only So number of equivalents will be what 0.04 divided by divided by 100 ml into 1000 That will be 0.4 This is 0.4 Now we use n1v1 is equals to n2v2 So n1v1 is 0.4 into volume is what? Or 10 ml of this solution is evaluated no so into 10 n2 into volume is 500 So when you solve this n2 you will get 0.008 Which is not there in the option Okay Yeah, but I thought it would be the closest like this 0.108 so that's why I marked that Fine, no issue So this is a normality you will get and this normality when you try to find out the mass is equals to equivalent By volume of solution is 500 into 1000 So number of equivalents you'll get here Is around 0.004 Which is mass by equivalent mass of oxalic acid 63 And this is coming to be around 0.252 gram Which is not there in the option Okay, so this we get this we get when you are taking molecular mass is 26 And for this the Questions should be hydrated oxalic acid. This is one thing Correct if it is dehydrated Then molecular mass is what 90 Okay, so this will get here what for dehydrated if you try to do Then the number of equivalents is what? number of equivalents is 2.52 given mass divided by the equivalent mass And that will be 2.52 divided by 90 divided by 2. What is this value tell me 0.056 0.056 you are getting Okay, so normality is what 0.056 divided by Volume is 100 into 1000 This will be 0.56 normal correct Now 0.56 into 10 is equals to 500 into n 2 n2 is what 0.56 into 10 divided by 500. What is this value? 0.011 0.011 which is again not there in the option right I don't think 0.011 is there in the option Is it? No So that's why the answer was wrong Okay I think the When you look at the data It should be hydrated oxalic acid Then you see this equivalent weight is getting cancelled and we are getting proper 0.04 equivalent here 63 252 by 63 They're getting points. So it should be hydrated oxalic acid. Tell me anything else Anything else? No, sir So then we'll wind up, okay