 So today we are going to start biomolecules regular classes whatever we are following over there that only will do Okay, so today we are starting biomolecules. Let's see how much we can finish it. We can finish this today itself That would be good Okay biomolecules So what are biomolecules? Have you finished this? So we did it for biology last year last year, okay So biomolecules basically see in this chapter because it is there in biology also So basically all those the structures of DNA and all you have already done in biology Okay, but here we'll see the you know the reaction aspect of biomolecules because it is chemistry So we have to focus on reactions and structures Okay, so that's what we are that's what we are going to discuss here biomolecules are what biomolecules are the organic compound so write down These are the organic compounds present in biomolecules are The organic compounds present in present as write down present as Essential constant went constant went of living organism living organism in different cells in Different cells like I said these are the organic compounds these compounds mainly contains mainly contains Atoms like carbon, hydrogen, oxygen, nitrogen, phosphorus, etc. Okay, so biomolecules It is actually responsible all these compounds biomolecules responsible for the For the building up for the building up of all the living system Responsible for the growth also we can say responsible for growth or maintenance It also provides the ability to reproduce so all these things we have it is Because of biomolecules only so biomolecules are basically the organic compound Okay organic compound Okay, organic compounds which are responsible for the growth of the living, you know organism Building up of organic of the you know the living system we have or it also provides the ability to reproduce It mainly contains these compounds mainly contains contains elements like Elements like Carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur, etc. Main constants of this okay this chapter actually there are four different, you know parts we have in this chapter so mainly in this You know chapter we are going to discuss about carbohydrates Like I said four different parts we have carbohydrates will talk about amino acids amino acids and proteins This is important for chemistry point of view. Okay. We have a nucleic acids also and lipids nucleic acids and lipids Okay, for you know for exam point of view chemistry point of view carbohydrates amino acids are the most important part Okay That is Mostly you'll get questions from here only what are carbohydrates anyone Basically this organic compounds are contain CH and oh so that like the primary substrates for respiration So basically, you know Carbohydrates like the name also suggest it is the hydrates of carbon right hydrates of carbon This was the No, the first kind of you know definition of carbohydrates We have hydrates of carbon and the general representation of carbohydrates of carbohydrates is In the form of this Cx H2o Why this is the general representation of carbohydrates Cx H2o y correct, so let us you know Let us, you know see some examples and then we'll see the no, no New version or the new definition of carbohydrates. What is the problem in this definition? We have that will see first and then we'll see the rectified You know definition of carbohydrates, okay the new definition of carbohydrates, okay, so this a formula or this definition Definition is not exactly correct. Why it is not correct. You see you see this example first I am taking one example here and that is h CH o. What is this? It is formaldehyde Okay, and formaldehyde is not Carbohydrate first of all, okay, but you know the formula representation of this you see can I write this as C1 H2o One can I write this? Yes, sir X and Y is nothing but one so this is also the representation of Formaldehyde, which is obviously not a carbohydrate another example if I give you if I write down CS3 COOH it is acetic acid Okay, it is acetic acid not a carbohydrate obviously and we can also write it as CO H2O or twice Okay, again the similar representation we have Lactic acid. What is lactic acid? CS3 COH HCOH So if you see this we can also write this as C3 H2O whole price correct 3 4 5 6 3 2 2 6 Okay, this is lactic acid. So point is these are not carbohydrates, but we can represent in this form That's CX H2O Y in this form Okay, another if I give you one more example here There's one example of carbohydrate and that is Rham knows our HAM N O S E Rham knows Rham knows is a carbohydrate and its formula is 66 H 12 O 5 So this is a carbohydrate. Okay, but if you look at this formula, we cannot write this in the form of CX H2O Y This representation for carbohydrate is not possible Understood Right. So point is what? The initial definition of carbohydrates that it is a hydrates of carbon, which is which can be represented in this form So there are some other compounds also ltehyde acids Which can also represent in this form and obviously they are not Carbohydrates one example we have of carbohydrate that is Rham knows right Rham knows Formula is this but this is a carbohydrate, but still it cannot represent in this form, which is the definition given by Initially that definitely given by right. So obviously there is a you know What we say? Problem with this particular definition. Okay, we cannot define carbohydrates with this particular way, right? So that's why we have given a new definition of carbohydrates. Okay, and this definition is found to be wrong Okay, this definition is found to be wrong and hence Found to be wrong and hence we have given a new definition of carbohydrates So what is the new definition and the definition which you need to write in the exam if they ask is this only definition of carbohydrates right down here it is these are the All of you write down this definition these are the optically active optically active polyhydroxy polyhydroxy aldehyde or ketone aldehyde or ketone Optically active polyhydroxy aldehyde or ketone which can which can also be Broken down broken down into into a small polyhydroxy Aldehyde or ketones Or ketones through hydrolysis Hydrolysis, so this is the destination of carbohydrate Optically active polyhydroxy aldehyde or ketone, which can also be broken down into a small polyhydroxy aldehyde or ketones through hydrolysis Am I clear? What do you mean by polyhydroxy? So more than one Yeah, two or more hydroxy group present Right two or more hydroxy group present for example For example, the first one is glucose The formula of glucose is New to yourself guys meet yourself, please So you see the formula of glucose is we have aldehyde as the primary functional group C double bond OH Here we have OH H OH H OH H OH H and this side we have CH2 OH, okay Copy down this This one here We have CH2 OH This is C double bond O And then we have H OH Right side we have OH OH Let's say we have H H and here we have CH2 This molecule we call it as fructose the another example of carbohydrates fructose Okay, now what is the primary functional group in glucose? See there are two functional group here. All of you try to understand here. One is alcohol OH So more than two are Like two or more than two we have here. So it is polyhydroxy And the another functional group is aldehyde. So aldehyde is The primary functional group because it is it dominates the It dominates the Alcohol right that's why this is the primary functional group. We have similarly here also we have polyhydroxy ketone it is right And ketone dominates hydroxy. So this is also the primary functional group Okay, so fructose the primary functional group is ketone And glucose the primary functional group is aldehyde Is it clear? Yeah, okay. So these structures you must know one thing also you must take care of here that the Last four carbon of glucose and fructose Have same configuration you see here this part This part and this part have same configuration here So that you must keep in mind that the last four carbon Okay, have the same configuration why i'm talking about configuration here because this carbon you see all these carbons are Chiral carbon if you try to you know observe this this carbon is a carol carbon This carbon is a carol carbon This carbon is a carol carbon and this carbon is a carol carbon Yes or no Here also this carbon is a carol carbon. This is a carol carbon and this is a carol carbon And that's why in the definition we have optically active polyhydroxy aldehyde or ketone Is it clear all of you? Yes, sir Sorry So pfg is pfg is primary functional group Yeah, or principal functional group because aldehyde dominates hydroxy alcohol That's why principal functional group is aldehyde in glucose and principal functional group is ketone in fructose Okay, sir understood This is one thing if you have a compound like if i write down one compound this way Suppose we have ether linkage here h And here we have h o h This is also polyhydroxy Okay, c h 2 o h here Here we have o h h c h 2 o h And hydrogen here and here we have c h o and c h o Okay, now when you do the acidic hydrolysis of this one h plus h 2 o Okay acidic hydrolysis Right, so the reaction takes place at this ethyl oxygen Right, so simply you can write this way that this combines with h more electronegative goes with or less And less goes with more this carbon oxygen bond breaks And the product we get here is what the product is this We have o h etch o h etch c h 2 o h c h o And the other product we get is We get is o h etch etch o h c h 2 o h And c h 4 You see on Sir for the second one why was the configuration flipped for the second one won't you just get to diastomeric forms? No, no, I am not talking about configuration here. Whatever it is Right, I have just written this way. There's just this bond breaks and I have written this normally I'm not talking about enantiomers diastomers. Whatever it is. Okay that that you let it be now We'll come to that later what I am trying to make you understand here that this molecule Okay upon hydrolysis gives you polyhydroxy aldehyde That's why this is also a carbohydrate Okay, that's the definition we have And uh, sir one other question. Um this representation, um, isn't On the glucose and fructose cyclic in nature. So this is post hydrolysis, right? What what this is on hydrolysis Or this is on hydrolysis of glucose and fructose. We draw the structure, right? These structures Yes, sir because Sir, but then uh on the cyclic in nature These two. Yes, we have but that will discuss. That's why fructose also shows tolerance test With glucose fructose and mannose. They are in equilibrium. They are in in a mixture there. You have all three forms you'll get Yeah, I will discuss that for us. Just give me some time. We'll discuss that. We'll come to that Now just we are trying to understand here what the definition of uh carbohydrates If you have ether linkage like this also on hydrolysis, this also gives polyhydroxy aldehyde, right? That's why this compound is also carbohydrate