Hello kids! Alright, hello my beautiful students. Welcome back.
This is your very own PaceBatch and I am your Steena Ma'am, your Zoology Mentor. So guys, how is your studies going? Do let me know in the comment section. There are a lot of syllabus and yes, every day I am getting messages in comments saying ma'am test low, test low guys, test will be taken for you. But But yes, many people have told me in the comments that ma'am, complete the syllabus first because many people are coming for exams.
So I think this is a very valid reason that we can postpone our test a little bit. We can postpone our live session in which we will talk a lot, take tests, we will interact a lot. So first we will complete our syllabus. So on Sunday, I had thought that we will take a test, a mentee quiz.
But we will not. We will have a class on that day too. So yes, we will have a class on Sunday too. Is that clear?
So let's get back to studies. So guys, we have started with this chapter of biomolecules. In which we have studied amino acids, proteins, fats, nucleic acids. And today we are going to discuss carbohydrates, carbs, sugars, sweets.
Okay, let's start our sweet talks. Guys, we will start with the word meaning of Carbohydrate. So, Carbohydrate means hydrates of carbon. It means that the amount of carbon is the same as water molecules. So, this gives us the general formula.
This is the general formula of carbohydrates. But this formula will only work for monosaccharides. It will work for simple sugars. Is it clear?
So, the more carbon atoms there are, the more water molecules are present in our basic sugars. Is it clear? Now guys, we can classify carbohydrates in many ways.
Now, as soon as you hear carbohydrates, you must be thinking that sugar is sweet. But let me tell you, not every carbohydrate is sweet. So, yes, let's start classifying them and we'll see which are actually sweet sugars and which are not. So guys, first of all we will classify carbohydrates on the basis of number of sugar units.
Basis of sugar units or sugar residues. How many sugar molecules are there? If there is a single sugar molecule in a carbohydrate, then we call it monosaccharide. Mono means one, saccharide word is for sugar.
It means there is a single sugar molecule. If we break it further, then we will not get sugar. If we break it, then it depends on how you break it.
Like in respiration, If we completely break down it in the presence of oxygen, we will get carbon dioxide and water. And if we break it down incomplete, we can get a lot of things. Lactic acid can be made, ethyl alcohol can be made in carbon dioxide.
Are you getting this? So it depends. But if we break it down completely, then if we break down single sugar in monosaccharides, then we will get carbon dioxide and water. That means sugar is not found when it is broken further. It is a complete sugar molecule.
Like glucose, fructose, galactose. Today we are going to talk about many sugars. We are going to see their structures.
Then comes disaccharide. Now di means two. So there will be two sugars. If I break disaccharide, then I will get two different monosaccharides.
I will get two sugar molecules, units. Is that clear? Then we have oligosaccharides.
Oligo means 2 to 9 or 10. It is given separately in different books. Many times disaccharides are included only in oligosaccharides. But here we have made a separate class because we will be discussing these two in special details. Otherwise, disaccharides can also be included in oligosaccharides.
When sugar molecules are added from 2 to 10, then what will be made? Our oligosaccharide. Clear?
disaccharides will come in it, trisaccharides will come, tetrasaccharides will come and so on. Like there are 2 sugar molecules in it, refinos will have 3 sugar molecules, right? So if you break refinos, you will get 3 different sugars, glucose, galactose, fructose. Okay, now if we add more than 10 sugar molecules, then what will become? Polysaccharides.
Is that clear? So this is a basic classification of sugars and carbohydrates on the basis of what? On the basis of the number of sugar residues joining together. Okay. I know.
Already you must have started thinking that reducing, non-reducing is also something. Right? Absolutely. We will be discussing which sugars are reducing and which are non-reducing. To tell you in detail, monosaccharides are reducing sugars.
These are reducing sugars. Okay. And... The polysaccharides and oligosaccharides are non reducing sugars. These are non reducing sugars.
And these are not sweet either. And if we talk about disaccharides and oligosaccharides, then some of these are reducing and some are non reducing. Like lactose, maltose, these are reducing sugars. These are reducing.
While sucrose is non-reducing and this comes with a question. What will come on this? Question. Which is the non-reducing disaccharide?
That is sucrose. Basic 2-3 questions are ready. And from here you also know the classification.
First remember which sugar comes in which category. So that if a simple question comes. Which of the following set of sugars are disaccharides or monosaccharides?
or polysaccharides, you can clearly answer that. We will go step by step. Is it done?
Now, let's come to the details. As I told you, monosaccharide means it contains single sugar. Saccharide means sugar that cannot be hydrolyzed into simpler carbohydrates. If I break this, I won't get more sugar. So, it is made up of, contains One sugar residue.
It contains one sugar residue. Is that clear? Like glucose. Like all of these.
Now guys, how much carbon number can be there in the monosaccharides? There can be carbon from 3 to 7. Is that clear? I am not talking about the sugar. I am talking about the carbon atom.
Jiska maine general formula tumhe abhi bataya tha. General formula being. General formula humare kya tha iska? The general formula was jitna carbon, utna water.
Or you can write it like this. CnH2nOn. For example, C6H12O6.
But now look, when we hear C6H12O6, what comes to our mind? Glucose. But this is a common molecular formula for all the head sources.
All the six carbon sugars have the same formula. So, the general formula of glucose, galactose, fructose is this one. Now, if we talk about triose, then what will be made?
C3, H6 and then O3. Is that clear? Similarly, what will be made of this? C4, H and O. Similarly, C5, H10.
O, we already know this. And C7 would be, sorry, 7 carbon sugars will be C7, H14 and O7. Simple? So this is the general formula of these sugars. Now we can give different names to these sugars depending upon what is inside them.
carbon atoms. See, if there are 3 carbon atoms, then we will call it tri. And guys, behind their name, generally, Ohs are used.
What will come after their name? Ohs will come. See, here triose, trioses, tetroses, pentoses, hexoses, heptoses.
And this tri stands for 3, tetra for 4, pent for 5, hex for 6 and hept for 7. So, you are understanding the name. Now let's talk about their examples. Now I am leaving out Aldosis and Ketosis for the time being.
We will be coming on to it slowly. Now just look at the examples. What are the examples of Triosis? Dry Glyceraldehydes and Dihydroacetone. When you will read the name, when you will read glycolysis, when you will read the respiratory cycles of plants and plants, you will see all these sugars.
Then, In Tetrosis, we have erythros and erythrolose. Then ribose, xylose, ribulose and xylulose. Glucose, galactose, fructose.
Okay. You can write one more in this. Manose. Manose will also come in this.
Okay. Glucoheptose and pseudoheptulose. These are different examples. Okay.
You can ask, in which one, how many carbon atoms are present. Done. So guys, we will go step by step. In starting, I am just telling you the classification. In which we are talking about monosaccharides, disaccharides, how many carbons are there, how many sugars are there.
Slowly, after doing this, then we will move on to the structures. Okay. First, we will just see the examples.
In the second part of the lecture, we will be coming on to the structures, which is very interesting. Okay. And I will tell you one and after that you will make all the diagrams.
Easy. Let's go. So second is disaccharides and I told you that disaccharides have two sugar residues. It has two sugar residues.
Two sugar residues. Is that clear? So if I break the disaccharide, hydrolyze it, then what will happen? You will get two sugars depending upon which two sugars were added.
For example, lactose. So lactose is made. Galactose and glucose molecules. So what were glucose and galactose in themselves? Monosaccharides.
What are they combined to form? Disaccharides. Similarly maltose. Maltose is made up of two glucose residues. Glucose plus glucose.
Similarly, there is an isomaltose. Isomaltose is its isomer. Which again will be made from two molecules of glucose.
But now it depends on how the units of two glucose are connected. Is that clear? Chalo, ye dheere dheere hume sab samajh mein aayega. Filhaal aapko ye bhi yaad karne hai. Kyunki questions mein ye bhi aata hai ki which of the following are the monomeric units of lactose or maltose or isomaltose.
Are you getting this? And then very important, humari non-reducing disaccharide that is sucrose is made up of one glucose molecule and fructose molecule. Is that clear? Is that clear to all? Okay.
So, you are understanding this. As such, you have to remember their units as well. Okay. Now, see. Lactose.
Where will it be present? Lactose is found in your milk. Right.
So, we can also call it milk sugar. Okay. We call it milk sugar.
Maltose. You will get it in malt. So, that is also known as malt sugar. Right.
And then talking about isomaltose, which is not given in your book, especially sucrose. This is your table sugar. Okay. And cane sugar. Done.
Let's go. So guys, this is about disaccharides. Again, we will do structures now. Step by step, see what types of things are made. Done.
Let's go. Now, you should remember which two compounds are there in it, which two sugars are there. Then we will come to the structure of these sugars and join them.
With the help of glycosidic bond. I remembered from bond guys. Yesterday in the lecture, we had studied ester bond.
Right, between glycerol and fatty acids. So in the comment, a child had a very strong doubt. That ma'am, the H in glycerol is not substituted, OH is substituted.
That means glycerol is giving OH. And the fatty acid, COOH, acidic group is giving H. So guys, let me clear it. If any of you have this doubt, then it is not like that.
Okay, the glycerol will contribute H and the fatty acid's COH will contribute OH. And for your sake, I have reconfirmed it with the chemistry experts as well. Okay, so no doubt and let's continue with the study.
Okay, so let's move on to oligosaccharides. I told you 3 to 10 is written, in some books 2 to 9 is written, so it will work in both. 2 to 9 sugar residues are present.
Is that clear? So guys, jiske andar 2 sugar residues present hongi. Tike? 2 hongi to unko disaccharides bol diya.
2 sugar residues, to we'll call it disaccharides. If there are three, then trisaccharides. If there are four, then tetra and so on. Okay?
So, not much naming is done. Just, they are called. Simply, we will say polyglycerides. Is that clear?
We have seen many examples of disaccharides. Try to remember a reference of raffinose. You don't need to do more than this. Done?
Okay. Then, coming on to polysaccharides. Now, see.
Polysaccharides will have more than 10 residues. More than 10 residues. Sugar residues.
Clear? Alright. More than 10 sugar residues joined together by the glycosidic bond. We had also studied glycosidic bond yesterday.
Let me know in the comment section, which two units did we see glycosidic bond in yesterday? I am giving a hint, it was in the topic of nucleic acid. Let me know, which two molecules make glycosidic bond in the nucleic acid? Okay? Let me know in the comment section.
Then, We are talking about polysaccharides. If there are more than 10 sugar residues, then it will be called polysaccharide. Now, guys, polysaccharides will be classified on this basis.
We will classify polysaccharides on the basis of monomeric units. So now look at the types on the basis of monomeric units. On the basis of monomeric units. How are the sugar residues that are attached?
If the sugar that is attached is all the same, then what will we call such a polymer? What will we call such a polysaccharide? Homo.
If the sugar residues that are attached are different, then what will they be called? Hetero, right? Homo polymers, hetero polymers.
Now, see what are the names of its homo polymers and hetero polymers. So, we have hetero polysaccharides. Hetero polysaccharides means the sugar that is attached will be different.
And then we have homo polysaccharides. Homo. Polysaccharides. Clear?
Now, understand. Now, here the question will come. Homo will have the same sugar residues.
Right? Same sugar molecules or residues. Like all the glucose, glucose, glucose.
Or all the galactose, galactose, galactose. Clear? Now, let's come to hetero. Here we will connect different, different.
Alright, now let's come to their examples which are important. So in homo saccharides, we have first example of starch. We have starch. Second example is glycogen.
Third example is cellulose. Fourth example is inulin. And the fifth example that we have to do is chitin. This is the same chitin that you will find in the cell wall of the fungus and you will also get this name chitin while reading cockroach.
In fact, all the arthropod exoskeletons are made of chitin. Is that clear? And that is a polysaccharide.
Question here is, number 1, which are homopolysaccharides? Okay, first I will tell you about hetero polysaccharides. So see, heparin.
Heparin, yes, heparin, the anticoagulant which does not let your blood clot inside. It is a polysaccharide, hetero polysaccharide. And it is mucilaginous, mucopolysaccharide, i.e. it retains water.
Then we have hyaluronic acid. Guys, this Hyaluronic Acid is a very interesting polycycline. Like, quite interesting. I don't know whether you are interested in beauty techniques or not, but I am.
Right? Like, it's one of your career options also. After MBBS or BDS, you can pursue this thing.
Like, beauty treatments. These days, there are a lot of them. You must have seen that whenever actresses enter the Bollywood industry, they don't look as beautiful. But within a span of six months, they look beautiful.
they look all the different, right? The cheeks that are filled in the inside, they become fuller, the lips become bigger, right? You must have heard about these tongue lips, or lips like Angelina Jolie. So, what is that thing that fills in their lips, or fills in their cheeks, so that they become fuller?
So, it is this hyaluronic acid. Very interesting. Okay?
And you know, it doesn't have any side effect. Except for the fact that you can use it with your natural look, with a little, You are changing it but it's okay right? It's okay. But there is no side effect of this because it is already present in your body a lot.
Now you must be knowing that the most abundant tissue in us is connective tissue. And in connective tissue is full of hyaluronic acid. So it is added from outside so that our fullness starts, skin gets full, glow or lips get fuller.
Those lips like Angelina Jolie are in fashion nowadays. So it is this hyaluronic acid. Its property is that it retains water. So when you put even a drop of hyaluronic acid inside and the water in the body, It will retain it inside and it will swell up so that the skin becomes tight. So yes, right?
So it is very interesting, we will talk about it some other time. Then we also have keratin sulphate. Now I am not talking about keratin guys, I am talking about keratin sulphate. Keratin is a protein. Okay, let me know in the comment section what is the structure of keratin.
I should keep getting this information whether I am studying or not. So what is the structure of keratin? We have discussed primary, secondary, tertiary and quaternary structures of proteins.
What is its structure? You will tell in detail. Is that clear?
Keratin is a protein but keratin sulfate is a hetero polysaccharide. Okay. Similarly guys, chondroitin.
Chondroitin is your cartilage protein. But chondroitin sulfate is again a carbohydrate. Is that clear?
So first of all, you should remember this classification. You should remember. Done. So you should remember which is homo and which is hetero.
Okay. Now let's advance a little more. Right? Come on.
We have to prepare for medical, we should always be ready to learn more and more, right? But first, after preparing the base, not that we are holding thick books and basic NCRT does not come. So basic NCRT is done.
Now I am telling you a little detail. Okay, see. And it is given in NCRP as well. Now see, homopolysaccharides are their units, i.e. monomeric units. Now the question comes, what are the monomeric units of starch, glycogen or cellulose?
What are their monomeric units? So guys, starch, glycogen and cellulose are made by combining all these glucose units. i.e. by combining glucose, glucose, glucose, these three types of polysaccharides will be made.
But it depends on how they are being joined. We will be seeing that in the structure. Okay.
But what are the monomeric units of these three? What is the monomer of all these? Glucose. Okay.
Now, in this way, see the monomer of inulin. Their monomer is fructose. What is the monomer of inulin?
Fructose. And chitin. Very important.
Very important. Its monomeric unit is NAG. What is its monomeric unit?
NAG. I am writing here, what does NAG stand for? NAG, remember NAG, N-acetylglucosamine.
N-acetylglucosamine. Okay, there is an amino group present in glucose and it becomes glucosamine and it is also acetyl. So if you keep adding N-acetylglucosamine, what will happen? Chitin and it is very very important. Where is it found?
In the fungal cell wall as well as in the exoskeleton of arthropods. Is that clear? I am sure you are enjoying it and it is not as tough as you thought.
Let me know in the comment section. Guys, this is online but I really want to interact with my students. So, the only way to interact is through comment section.
And it feels so good. To know that you are understanding things, you talk to me, you let me know where there is a problem. I really want to be available to you just like an offline teacher. But the only medium is through comment section.
So don't stop writing there. Clear? Let's go. So, polysaccharides are done guys. So, we will remember the naming.
After remembering the naming, what have we done till now? We have done classification on the basis of number of sugar residues. Clear?
Let's go. Then let's move on. We will move forward slowly. Now we will come to their structures. So guys, first of all I am starting, Don't focus on this structure, I will explain it now.
First of all I am starting the structure of monosaccharides. Monosaccharide means of single sugar. We will start the structure of monosaccharides. Now guys, monosaccharides are They exist in two ways. One is linear structure.
Straight chain structure. And the other is ring structure. There are two structures. One is straight chain.
Sorry straight or linear structure. Okay. And the other is ring structure. Now guys, the ring structure is of two types. Okay?
The ring structure is of two types. One is this and the other is this. Is that clear?
So, ring structure can occur in two forms in case of monosaccharides. One is furanose structure. while the other one is pyranose structure pyranose structure those structures to get straight your linear structures and other one is pyranose or furanose structure clear?
Here, so this is a linear structure. This is for glucose. Now, we have made this linear structure as ring structure. Done? Okay.
These are two types of expressions. Now see, coming back here. So, we are talking about ring structure.
Now, ring structure exists in two types of monosaccharides. One is pyranose and the other is furanose. Now, let us understand what are the differences between the two. Guys, Furanose structure is such that it has a six-membered ring.
We have six-membered ring. Okay? Right? And in this six-membered ring, look, there is a six-membered ring. And in that six-membered ring, one place takes oxygen and five places get carbon.
Okay? Six-membered ring in which one space takes oxygen and five spaces get carbon. Okay? This... structure such membered ring, what we call such 6 membered ring, pyranose structure.
Glucose has pyranose structure. Can you see it here? See this. So this is the pyranose structure.
So this is oxygen, this is first carbon, this is second carbon, third, fourth, fifth and sixth goes in here as a side chain. Understood? So this is the pyranose structure.
This is fifth, this is fourth This is third carbon, this is second and this is one. And who has taken one space? Oxygen has. So, how is this glucose structure? Pyranose structure.
Clear? Now, let's come to furanose. So, what will happen in furanose structure?
In furanose structure, guys, there is a five-membered ring. What kind of ring is it? Five-membered ring.
Okay? And in five-membered ring, Here, in the five-membered ring, one place has gone to oxygen, one place has gone to oxygen, and the other four places have got carbon. ok, the rest of the space is carbon so one space goes to oxygen and four positions goes to carbon inside the ring it is not like that you can't express six carbons inside the ring you can do it you can do it, ok like see here the ring is five membered see here, this ring is five membered first is oxygen, then this, this, this, this and this, so there are how many Sorry, 4 places for Carbal.
Right? There are 4 spaces in the ring. But if I want to express 6 Carbal sugars here, then how will I make it?
See here, CH2. From here, 1 started. This became our 2. Okay?
This became 3. This 4, this 5 and this 6. So, it can be expressed. But in the ring, 5 members will come. One of which goes to oxygen.
And who goes to four places? Carbon. Is that clear? So, the sugar structure which is like this, i.e. pentagonal ring, okay?
That sugar itself can be exhausted, but the ring structure is pentagonal. So, what will we call such ring structure? Furanose structure. And this is the structure of? This is the structure of?
Fructose. Whose furanose structure is it? Fructose. Okay? Ribose.
Let's make pentagonal ring of deoxyribose, it has 5 members but ring is also made like this, we did structure yesterday. So, fructose, ribose, deoxyribose, all of them have such structure. Clear? Whereas glucose, galactose, maltose, all of them have such structure. Not maltose, sorry glucose, galactose and mannose.
Glucose, galactose and mannose. Okay. What will be their structure?
Their structure will be pyranose structure. Whose structure is this particularly? This is the structure of fructose.
But how is the structure of the rest? Furanose structure. Similarly, whose structure is this?
Glucose. But how is the structure of galactose and furanose? Piranose structure. Is that clear? Now, is it clear?
Now, guys, let's come to their individual structures. I am saying one line first. Then I will explain it.
Now, see. Glucose. galactose and mannose.
These are all 6 carbon sugars. Hexoses. And all these are epimers of each other.
Epimerss of each other. Epimerss are isomers. Now you know the basic understanding of isomers, whose molecular formula will be same but structural formula will be different.
So this means that all the structural formula, see all these we did in the table, let's go back once. See all these, their structural formula will be different but their basic formula is same, their molecular formula is same. So all these pentoses are all isomers, these are all isomers, these are all isomers and so on.
So now they are studying their structural formula because their molecular formula will be the same. Now I have written a line here that they are all epimers of each other and epimers are a kind of isomers. Now understand what epimers are. Now just observe the structure very carefully.
First just look at glucose. See this is glucose. Once again, how are these two structures? They are six membered ring, so they are pyranose structures. Now I am talking about glucose.
This is carbon number 1, carbon number 2, carbon number 3, 4, 5 and this is carbon number 6. Okay. Similarly, come to galactose. This is carbon 1, 2, 3, 4, 5 and 6. Just observe it for a while.
Pause the video and just observe and see. Do you feel any difference in it? It is clearly highlighted.
Now, if you have unpaused it, let's understand what is the difference. Here you will see the same structure. See here on 1, on carbon 1, OH up, H down, OH up, H down.
On 2 also same orientation is there and same things are present. But come to carbon number 4. It is the same H and OH but the orientation of H and OH is different. Only orientation. Here H is down, OH is up, here H up, OH is down.
So guys, the same things which are present in each other, isomers whose rest of the structure is same but their orientation on a particular carbon is different we call such isomers epimers so once again what is epimers? Epimerss are isomers in which the orientation of H and OH is different on just one carbon. So epimers are isomers in which orientation of H and OH is different on just one carbon.
of H and OH is different. At a particular carbon. At. They should be different along just one carbon. At a particular carbon.
Like here in glucose and galactose. So can we say that in glucose and galactose. There are epimers in glucose and galactose.
Which carbon? At carbon number 4. At carbon number 4. So which one is the difference between these two? Only at carbon number 4. Now I am making one more example.
Now see. Now I am making one more epimer of glucose. At carbon number 2. Epimers at carbon number 2. Now see the structure here.
We have to make all the same. Okay. All will be same like glucose. There will be difference like glucose.
One. Two. Three. Sorry.
Okay. So, rest will be same. this is one two three four five and six ticket now see one two three four five and you have a CH2OH so this is six. The rest is all same, all same, only the orientation will be different on carbon number two. What is carbon number two here?
Let's observe. Here carbon number two, see H above, OH below. What will happen here?
Here OH above and H below. So this is the difference. Rest of the same will go.
Same means like that OH up, H down. Okay. On 3rd, OH up, H down.
On 4th, H up, OH down and the same. The difference is only on carbon number 2. So this sugar is called mannose. What is the name of this sugar? Manose.
So glucose and mannose, they are epimers at carbon number 2. Let me know in the comment section, Galactose and Manose, are they also epimers or not? Just observe the structure. Is that clear?
Okay guys, so pause and observe it. And answer it in the comment section. What do you think about Galactose and Manose?
Do they show epimerism or not? Is that clear? Okay. This is the one type of isomerism we have studied.
Now, I am telling you another type of isomerism guys. And the other type of isomerism is Anomerism. Now we will study Anomers.
We will study Anomers. Now see, these are also isomers. We have two forms in them.
One is Alpha forms and one is Beta forms. You must have read many times Alpha glucose, Beta glucose. So these Alpha and Beta forms are Anomers.
Anomers are also isomers. The difference between them is that what happens in Anomers above Carbon 1? Orientation, we have to see the position of H at carbon number 1. On its base, we have to see the position of H at carbon number 1. So A for alpha, A for above. Here at carbon 1, H is above. Observe there.
And beta, B for beta, B for below. Okay? There is a way to remember.
So, H is below. Where? At carbon 1. Okay? Come here. Now, see here.
Here, at carbon 1, H is below. So, what form will this be? H is below.
So, which form of glucose is this? This is beta glucose. Here also, galactose. Here, look at carbon number 1. H is below carbon number 1. So, this is also beta galactose.
Here also, I have drawn casein mannose. Casein mannose is drawn. This is carbon 1. Hydrogen.
H is below. So, this is also beta mannose. Is that clear? That means, if I draw the same structures, but H above and OH below, then which forms will be formed? Alpha forms.
Maniac! I am making one and telling you the rest you will make it yourself. I am telling you about the manuals. It will be the same.
We have to check on carbon number 1. Everything else remains the same. Same will remain. H up, OH down. Same will remain here. OH up, H down.
Same will remain here. OH up, H down. Only carbon number 1 will make a difference.
Here H will go up. And when H goes up, OH goes down. So H up. This becomes alpha mannose.
This becomes alpha mannose. Is that clear guys? Similarly, you can make alpha-galactose. Do try it once. Don't just listen to me.
Because until you make these structures yourself, you won't be able to make it. It's better to make them together. Similarly, draw alpha-glucose.
Clear? You should know this. It is very easy to remember alpha and beta.
A for alpha, A for above. Right? So we have to see H at carbon number 1. If you raise H to alpha form and lower H, then it will become beta form.
Is this much clear? So guys, this was something about the structure of monosaccharides. Clear?
What are their forms? Pyrannose or furanose. Okay?
And the structures are What kind of isomerism can they show in each other? Now let's come here. This is the glucose structure.
This is the linear structure. This is the ring form structure. And which is this ring form structure?
See here carbon number H above. So which carbon is this? This structure is H above. So this is beta glucose. So H is above.
This H is above. So this is alpha glucose. So, we saw here that H was below so this was beta glucose. Is that clear guys?
So, in this way you can make it in the form of alpha and if I change the orientation of glucose to carbon number 2, it will become mannose and if I change it to 4, it will become galactose. Is that clear guys? I hope. You are clearly knowing these things. Now see this is the structure of your NCRT ribose.
By the way guys, all the structures in NCRT have to be done. Yesterday we had left the structure of phospholipid in the fats. So do that.
The structure of cholesterol and phospholipid lecithin which we have been studying in the respiration again and again. The surfactant, right? Which makes the Clara cells, type 2 cells.
So that is very very important. Do those structures. All the structures of MCRT are important.
If you don't come to make. Then you can come to identify in NEET. But you should be able to.
Is that clear? So this is ribose structure. And guys we had read this yesterday.
What is this? We had read yesterday that ribose. Has one oxygen deficiency. And what has become? Deoxyribose.
At which carbon number 2. Here. Upside is H and downside is H. Here above H, below OH. Is that clear guys?
So this is the structure. This is known as RNA sugar. We had read this yesterday. And deoxyribose is the DNA sugar. Clear?
Alright. So now, we have talked about monosaccharides. Now we will talk about big sugars in which monosaccharides will be added.
The point is that whenever two sugar molecules are added, a glycosidic bond is formed in between. So where will the formation of glycosidic bond be? Between two sugars.
Which bond will be formed between any two sugar residues? Glycosidic bond. And till now all the bonds we have discussed, be it, first we talked about peptide bond between amino acids, then we talked about ester bond between fatty acid and glycerol, we have talked about in DNA, so many bonds except for hydrogen bonds, rest all the bonds we have discussed, be it glycosidic again, and then phosphoester, phosphodiester, Water molecule was coming out everywhere.
Same situation will happen here. This bond will also be formed due to dehydration. Now what happens here? See here, between two sugars, I am making any two sugars. I am making any two sugars.
Whenever any two sugars will react, then their adjacent carbons, see here H and here OH, I took it like this. Now understand how binding will be done. So whichever is adjacent, see which one is adjacent here? Here carbon number 1, 2, 3, 4, 5 and whatever.
It starts from here 1, 2, 3, 4. So here which two sugars, sorry both the carbons are adjacent. It is carbon 1 and carbon 4. So the OH of carbon 1 and carbon 4 There will be an interaction between them. Glycosidic bond will be formed between the OH of both.
And from both Oh, one will give its H and the other will give its OH. And from here, the water molecule is formed and leaves. Is this much clear?
When the water molecule leaves from here, can I write it like this? See, the water molecule left. So what happened?
One gave H and the other gave both Oh. So one oxygen came in between. What is the linkage of this type of bond? When both are on one side, what is the linkage?
Alpha. Which sugar is in between? 1 and 4. It is known as alpha 1,4 linkage.
Is that clear? You should know the linkages. The reaction of two sugars will always be in between 2 OH. One will give its OH and the other will give its H.
It will become a water molecule and leave. Is that clear? Now, reaction can be done like this also.
Let's make it again. I am making a short one here. See here.
So, suppose H is here and OH is here. At carbon 1. And this is its carbon number 4. Now its OH is above and H is below. Reaction will happen here also. And the reaction has to happen always between OH.
So, what will happen here? Here, the reaction is going to happen. Like this.
So what will happen? A water molecule has been released. Okay?
So see what happens. So this was H and this is O. This O went in the middle. And this is how our bond will be formed.
Is that clear? Now see this. This is linkage between carbon 1 and 4. But it is a diagonal linkage. So we call this beta 1,4 linkage.
Is that clear? Listen again. If you didn't understand.
See. Linkage should always be between OH. It is a sure thing.
Okay. Both Oh have to interact. Water molecule has to be removed.
One will give its OH and one will give its OH. Clear? Water molecule will be removed. So water molecule removed.
And how does this water come out? In this, H from 1, sugar from 1 sugar, sugar 1. And what will the other give? Its OH from sugar 2. So, this is how a water molecule is formed and leaves.
Behind two sugars, one bond will form and one water molecule will leave. Is this much clear? Okay? Now, it is very easy for you to make it. Very easy.
Okay? I will keep telling you which units are attached in maltose. In fact, we have already read that which units are attached in maltose. See, what was attached in the case of maltose?
In the case of maltose, this is maltose. What is attached in the case of maltose? We have sugar, two glucose molecules.
We have two glucose molecules. So glucose plus glucose. What will be formed? We will have maltose.
This is made maltose. Now see which is the glucose in this. H is above.
Here H is above. So this means alpha glucose is binding both. Okay.
Now here you will make alpha glucose. Just make the alpha glucose. Okay. You will make the structure yourself. H and OH.
Similarly you will make this whole structure. Okay. O, H and OH.
And this is carbon 4, this is carbon 1. There is interaction between carbon 1 and 4. Water molecule will come out from here. And if water molecule comes out, oxygen will come in between. Now what is the linkage? See what is the linkage?
It is between carbon 1 and 4 and on one side. So this is alpha 1,4 linkage. Is that clear guys? This is your maltose. Now, for us, sucrose is even easier.
Let's come to sucrose later. First, look at lactose. In the case of lactose, what do we have? We have 1 galactose. and one is glucose so this is glucose and this is galactose here in galactose H is below so this is beta here H is below so this is also glucose beta so it is a reaction between beta galactose and beta glucose is that clear?
now see here so their OH must be above see this, how did their reaction happen? So this was the OH part and this is the H. H is below, so beta galactose.
Now this is carbon 1. Similarly, now look here. This is OH and H. This is H and OH.
Now OH and OH have to interact with each other. So whenever there is interaction, then a water molecule will come out of here. Water molecule comes out.
One water molecule comes out. So this reaction is diagonal. So bond is diagonal. So what will we call beta? Beta.
And what will we call linkage? Beta. Between which carbon? 1,4 linkage. If it is formed in the same direction, then it is alpha.
If it is formed in the opposite direction, then it is beta. Is this clear to you? Now come back to the sucrose that we have left. Now see. In sucrose, we have one glucose and one...
fructose glucose plus fructose the fructose structure was furanose structure glucose structure was pyranose structure but never mind now first see what sugar is on glucose glucose is above H so this is alpha glucose Now what to do about fructose? In the case of fructose, carbon 1 is above H2CO3. OH was below, H is not there.
So in the case of fructose, we will see its position. If it is above, then it is alpha. If it is below, then it is beta.
H is not present at carbon 1. Carbon is starting from here. So, in the absence of H, we check CH2OH. We will check its position.
Otherwise, while telling alpha or beta, we check the position of H, of hydrogen at carbon 1. But in case of fructose, we will check the position of CH2OH. Is that clear? So, here alpha glucose, alpha, Fructose is interacting. So now see.
And which sugars are interacting? Sorry, carbons are interacting. One. This is two.
And here one. So one carbon of glucose and second of fructose are interacting to release a water molecule. Is that clear?
So when interaction is between one and two and one side is there, then what will you say? Alpha one two linkage. Is that clear?
So we will draw the structure of fructose. Like this, we first draw glucose. This is carbon 1. So this is H. This is OH.
H above. So, sorry, alpha glucose. Then we have fructose. Okay.
In fructose, CH2OH. This is carbon 1. This is above. So this becomes alpha. Okay. Here was OH.
So these two have shown interaction. They have shown interaction between each other. And what is this? This is carbon number 2. Carbon 1 has started from here. Is that clear?
So this gives us the structure of sucrose. Done guys. So this was our structure.
Lactose, sucrose. And now we come on to the structure of polysaccharides. Now more sugars will be added. But whatever amount of sugars are added, which bond has to be formed in between?
Glycosidic bond. Is this much clear? Come on.
Now guys, after listening to starch, you are so clear that starch is present only in plants. Stored form of sugar is in case of plants. This is the stored form of sugar in plants. Right.
Whichever extra food is there, it will be stored in the form of starch. Stored in case of plants. Okay.
And. Starch is a homopolysaccharide. It is a homopolysaccharide. All the units that are joined are the same. Whose homopolysaccharide is it?
What is its monomer? Glucose. What is its monomer unit? Glucose.
And that too, what? Alpha glucose. Is that clear? Now guys, the structure of starch is very interesting.
It is interesting because it has two types of chains. It is not all glucose-glucose but it is joined in two types. One glucose-glucose-glucose, all linear chains are joined.
It is just a linear chain. So, I will tell you that it has two chains. See, one is amylose chain.
This is the amylose chain and secondly it has amylopectin chain. Amylose chain is non-branching, i.e. straight chain and amylopectin is branched chain. Can you see it here?
This is the structure of amylopectin. This is amylopectin. Now I will draw amylose first so that we can see the structure of amylose. Now see, what will happen in amylose? Sugar molecules will keep joining with alpha-1,4 linkage.
So, these glucose molecules will keep joining here and there. So, it is a linear chain, straight chain. There is no branching present in it.
It is a non-branching. So, out of all the starches, 15-20% straight chains are present. Amylose chains are present.
Is that clear? Now, 80-85% of the part is of branched chains. Somewhat like this.
It is this. Now see what is there in this? This is also glucose alpha linkage on one side of 1 and 4. So glucose molecules are connecting like this but on every 25th carbon, not carbon, on every 25th sugar there is branching.
See there is a branch coming from here and 1 and 6 carbon are interacting. So where there is branching, how is the linkage happening? 1, 6 linkage.
So, how is the linkage at the branching point? One-sixth linkage. Is it clear?
And how is the linkage in straight chain? Alpha 1,4 linkage Is that clear guys? So it has two types of linkages Two types of chains Straight chains which we call amylose Branched chains which we call amylopectin This is mostly done And what will happen in branching?
On every 25th sugar a branch A sub branch will be present And with whom branch interacts? During branching 25th sugar's sixth carbon interacts with the first carbon of the upper sugar again forming the glycosidic bond is that clear guys? and this is our starch which is the stored form of sugar and do you know what is the test of starch? which test is it?
tell me quickly I am remembering, iodine test right? in which our brownish yellow Starch, sorry, iodine that turns bluish black in presence of starch. Okay, starch will be there, so iodine will turn bluish black. Is that clear? Okay, let's move on.
Now, let's see glycogen. Guys, glycogen is our starch. Glycogen is known as the animal starch. Animal starch means the stored in animals. The form of food is glycogen.
The amount of extra food you are eating, is converted into glycogen. Even then you didn't stop eating. You were getting bored so you ate.
In that situation, it will start making fat. But, which fat is healthy and which is not, we had studied yesterday. Let's move on.
Glycogen is a stored form of sugar in case of humans and overall animals. They are not just humans. They are branched structures.
than amylopectin. We have done two types of chains in starch. We have done two types of chains in starch.
One is a linear chain and the other is a branched chain. In glycogen, only branched chains are present just like amylopectin. There is no such thing as amylose in it.
They are just branched chains, highly branched. Like in the case of starch, we said that branching will be present on every 25th sugar. Here, branching occurs very quickly. Every 8th or 6th sugar has branches present.
So it is highly branched structure. So this is highly branched structure more than the amylopectin. Major form of sugar in case of animals. And this is also homopolymer of glucose. Which glucose is it?
Alpha glucose. And where does branching occur? When it is attached to each other, then it is alpha-bore. And where does branching occur?
On alpha-1,6. Linkages occur at every 8th to 11th sugar residue And that was happening at 25th This is happening very fast So it is much more branched Is that clear guys? Let's see the inulin I told you that inulin is also a homopolysaccharide But what is its unit?
Its unit is fructose So fructose molecules will be joined here By beta 1,4 glycosidic linkages Not in your syllabus. Nobody will ask you so much detail, but I'm telling you. If you understood bonds, then try it out.
Let me know in the comment section whether you were able to draw this or not. Otherwise, next time I'll draw this for you. We'll draw it in class, however it is. How will it be made? Just to see if you've come to make linkages or not.
Just to clear the concept. Otherwise, it is not in your syllabus. Now, the interesting thing is that we get this found in tubers and roots of artichoka. Ask your mom, what is artichoka? Artichoka is used in corn starch as well.
Okay. So, artichoka or we get this in Delia roots. Your NCERT has given that we get this sugar in Delia roots. Guys, it is not insulin.
Okay. Many kids find it wrong that this is a spelling, but it is not. This is inulin.
Insulin is a protein, right? This is a carbohydrate, a homopolysaccharide made up of fructose units. And this inulin is used to test the kidney function. Is that clear?
It is used for the kidney function test. Then coming on to cellulose, it is very commonly heard. Cellulose is the most abundant carbohydrate present in the cell wall of plants. It is insoluble and it is made of beta glucose residue.
Beta glucose residues, till now we had said alpha glucose This is formed of beta glucose residues and it also has a bonding of beta 1,4 bonding It cannot be digested by humans because there is no enzyme present in it Which can digest beta linkages So this is the point Now you understood why we can't digest cellulose So cellulase, we have many enzymes which We break many polysaccharides, right? We can digest starch, we can do it, under the condition that it is cooked. But we cannot digest cellulose, although both are polymers of glucose. The difference is of beta linkage and alpha linkage. So, our amylase breaks only alpha linkage, not beta linkage.
That is why, without a doubt, our starch and cellulose... are made up of the same monomer but still amylase will act on starch and not on cellulose because of the difference in their linkages. Is that clear guys? Clear?
Shall we move ahead? Let's go. Lastly, let's see the hetero polysaccharides. So I have told you that heparin is our anti-coglant, hyaluronic acid, whose interesting story I told you about, those beast tongue lips, angelina jolie lips, are made up of hyaluronic acid. Keratin or Keratinol.
Keratin sulfate, one and the same thing. This is a Dermatansulfate. They are all found in the connective tissue and in the synovial fluid. In the synovial fluid, you will get all these polysaccharides. Okay guys.
So, there is not much detail about these hetero polysaccharides. Overall, you are asked which are homo polysaccharides and which are hetero polysaccharides. So, you must know that. In fact, when we eat bhindi, it is a sticky thing. And if you have ever tried to wash your hands after cutting the okra, then those hands become more slippery.
It seems that the mucilage is not coming down. So guys, what is that mucilage? That mucilage is also a polysaccharide.
That is a polysaccharide. Is that clear? Ok.
The jelly in the aloe vera is a polysaccharide which can retain water. And such polysaccharides which can retain water, we call them mucopolysaccharides. Is that clear? So hyaluronic, heparin, mucilage, they are all polysaccharides. In fact, you must have heard of ISSABGOL for constipation.
ISSABGOL is very useful. So guys, when we mix ISSABGOL with water, the mucilage in ISSABGOL becomes very soft. So what is ISSABGOL?
This is also a mucilage and what we obtain is a mucilage. And we get all these round from a plant whose name is Plantago. Plantago ovata, this is the name of plant from which isabgol is obtained. This plantago ovata has a husk of seeds, Do you understand husk?
It is the cover of seeds. That is isabgol. So guys, we get a moral of the story from this that seeds or grains should be eaten with its cover.
Very polished rice is not healthy. That's why we are coming back to brown rice and bran. We are coming back to very filtered, very thin.
The flour is also not healthy. It is important to have fiber in it. This is also a fiber which is healthy for us. Which cleans our gut. So, anyways, this mucilage is also a hetero polysaccharide.
It can retain water. It is a muco polysaccharide. Is that clear, guys?
So this is what we were supposed to study about carbohydrates. We are left with one topic of this chapter and that is enzymes. And guys, we will do that tomorrow. And before that, it's time for the burger quiz.
Okay. And the question for the day is, I am most abundant carbohydrate in the living world. Easy peasy question. So write the answer quickly.
Read all your NCRT and I will see you tomorrow with the last topic of the chapter. which is enzymes. One of my favorite topics.
Because without enzymes, our life could not work. We'll see tomorrow. Keep studying. All the very best.