Amino Acids: Structure, Definitions, and Classification

foreign [Music] have four valencies if I just make a basic structure we know that the carbon have four valencies if on one of the evaluency we are having the amino group that is nh2 one of the valency we are having the amino group the another valency we are having the acid group at the same time we are having the amino group acid group at the same time Amino means nh2 adding means coh if you are having same uh at the same time we are having the amino capacity group that is called as amino acid the third valency is hydrogen and the fourth valency can be anything so I am writing R it can be sulfur it can be alcohol it can be anything so I am writing R so this is a basic structure of amino acid this is a basic structure of amino acid amino group acidic group at the same time is aminas what is the third valence is going to be hydrogen fourth can be anything so I am writing R so what is r r means it can be any group it can be any group it can be hydrogen it can be carbon it can be carbon chain sulfur it can be anything so I'm writing r so once we are clear with this basic structure of amino acid now what we need to understand is few definitions uh that will make a base for this chapter of amino acid right so let's starting with the first definition that we should know is Alpha amino acid help amino acid so to understand this Alpha amino acid we need to understand that what is the meaning of alpha right so to make you understand that I am taking a just simple example let's say this is a carbon chain and having the carboxylic acid as a functional group right so if I want to do the carbon numbering we always start the carbon numbering from the functional group so uh here is the function group so we'll start with the carbon domain from here is carbon number one two three four and so on right this is one of the way of doing carbon numbering the other way of doing carbon numbering is that the carbon which is next to the function group say this is the functional group the carbon which is next to the function group is referred as the alpha carbon then the beta carbon Gamma Delta and so on right so what we have understood by this example is that what is Alpha carbon is Alpha carbon means the carbon which is next to the functional group carbon which is next to the functional the carbon which is next to the function group is referred as Alpha carbon if we apply the same concept of alpha Carbon on the amino acid on the amino acid then what we are going to appreciate is see this is the the carbon having four valencies one valence is having amino group another valency is having acidic group the third valence is hydrogen the fourth is can be anything from adding R so this is a structure of amines structure of amino acid because here is the main function group that is the coh then the carbon next to the function Loop the carbon which is next to the function group is going to be the alpha carbon it's going to be the alpha carbon in this Alpha carbon you can easily appreciate that this amino group is right now attached right now attached to the alpha carbon in this amino acid the amino group is right now attached to the alpha carbon so this is referred as Alpha amino acid this is referred as so this is referred as the alpha amino acid referred as Alpha amino acid so what is Alpha amino acid is that amino group is attached to the alpha carbon so let's write down the definition of alpha amino acid that the amino group amino group is attached to Alpha carbon if the amino group is attached to the alpha carbon that is referred as the what what happens in our body is that the most of the amino acid are found in Alpha for most of the minister are found in Alpha form there are some exceptions there are some amino acid which is not found in the alpha form and this is what we need to know so the exceptions to the alpha minus it means the amino acid which is not found in the alpha form exceptions to the alpha amino acid say they are beta linen beta alanine betaalanine the name itself is very clear that the amino group is attached to the beta carbon that's betal in it one more uh exception that we can add is beta Amino isobutyrate beta Amino isobutyrate gamma Amino isobutyrate so the name itself is very clear that we have a prefix that beta Island in beta amino acid rate gamma Amino isobitrate that the amino group is not attached to the alpha curve so this is the first definition that we need to remember in respect of the amino acid that is Alpha with acid let's understand the second definition that is with the name of kerial carbon carbon now what is the meaning of kerial carbon is if we know that carbon have four valencies carbon have four valencies if all the four valencies are having different functional group for example here it is X y z a what you can appreciate is all the four valances are different if all the four valencies are different then such carbon is referred as kerial carbon this is referred as kirial carbon is all the four valencies all the four valencies having different functional group leaving different function group or different atoms that is reference now why this serial carbon is important see you may have heard that something called as there is something called as Mirror Image there is something called as mirror image or the optic isomers mirror image or the optic isomers if we want to make a mirror image of any molecule the mirror image or the optical activity depends whether the molecule contains aerial carbon not if the molecule does not contain a kerial carbon then the mirror image is not possible so is only possible if a molecule contains kirial carbon if the molecule does not contain carbon the mirror image is not possible so using this information if I apply this concept here on this structure of uh amino acid here is the amino group the acid group so this is going to be amino acid the third valency is hydrogen let's see the fourth valency is also hydrogen so what you can appreciate is third and fourth valency are same because two valencies are same so I can say it is not a kerial carbon it is not a keryl carbon now once it is not a kerial carbon once it is not carbon but at the same time it is having the amino group acidic group so it is amino acid the name of this amino acid is glycine so what they ask is which amino acid does not contain girdle carbon that is a straightforward question the answer is going to be glycine or in other way they can ask this that which amino acid is optically inactive means which cannot make the middle image the answer is going to be glycine because it does not contain the cheerle carbon so let's write down this point that glycine does not contain keryl carbon hence it is optically inactive glycine does not contain keryl carbon hence it is optically inactive does not contain kale carbon so it is optically inactive this is the second definition the third definition that we should know is the third definition that we should know is amino acid so we have discussed about alpha mean acid and the kidial carbon the third that we are discussing is immunizing if I make the structure of amino acid carbon having four valencies on one of the valency we are having the amino group The acidic group the hydrogen and the fourth valency can be anything so hydrating r now here what you can appreciate is that the amino group is free p in the sense that it can make bond with the nearby amino acid it can make peptide bond with a nearby amino acid it is currently free this amino group is free but what I do is if I alter the structure of the amino group means right now this amino group is free but now what I do is I bound this amino group in a ring structure like this now you can see that I have made a ring around the amino group right this amino group is not free if the amino group is not free then this molecule is referred as amino acid referred as amino acid so what is amino acid that the amino group is not free is not free instead it is bound in a ring structure if the amino group is not free Bound in the ringing structure is therefore as amino acid what is very important is that what is the example of amino acid the example of amino acid is Proline Proline is the example of amino acid it does not have the free amino group sometimes they might ask that what is the name of this ring what is the name of this ring the name of this ring is this is referred as pyro leading ring so pylolidian ring is found in which amino acids found in Broly which is an example of immunize so these are the three definition to be remembered right so to summarize what we have discussed that the first thing that we need to know is the alpha amino acid in humans most of the amino acid are found in Alpha there are few exceptions and the most important exception that you should know is beta alanine now when they will ask this question they will not write this beta word in the options the reason is if they write beta then it's going to be very obvious right so the beta word they will remove they will just write Ln in Ln is the example of beta beta amino acid the the second thing that we have discussed was the kerial carbon kirial carbon or the optical activity so the point to be remembered is real carbon not found in which amino acid the only amino acid is glycine which does not have the kirial carbon it is optically inactive the third thing that we have discussed was amino acid the example of amino acid is very important is Proline the amino group is not free is bound in a ring structure so these are the three points to be remembered from this definition part now coming to the very important part of the chapter amino acid and that is in respect of the classification of amino acid classification of aminas so to do the classification of any group first we need to understand that how many amino acid we have earlier we have 20 types of amino acid now recently two more amino acid are added and now we have total 22 types of amino acid we have 22 types of amino acid and we need to classify these 22 group uh 22 amino acid so to classify any group any group say for example if we are having right now 22 student in the classroom and I want to classify these 22 students so what I can do is I need to have a basis on what ground I am going to do the classification say for example I can do the classification on the basis of your age 21 22 year 23 year 24 year and so on I again classified on the basis of your let's say the native state and so on right so on the basis of various thing we can classify the groups so the here also we want to classify the amino acid so first we need to understand that on what ground we are going to do the classification right so the first classification that we are going to discuss is based on the R group based on R Group what is R Group R Group is basically the side chain if I make the structure of amino acid that we have made earlier is the amino group LCD group hydrogen the four volts are the fourth valency was r as I told you earlier that R can be anything it can be hydrogen it can be uh carbon it can be sulfur alcohol it can be anything so based on that we are going to do the classification so the first subcategory the first subcategory if we do the classification that is based on the R Group the first subcategory comes out to be simple amino acid simple amino acid means that the R Group is replaced by either a simple hydrogen or by a simple carbon if you replace the R Group with simple hydrogen or carbon that is called a simple amino acid the example of simple amino acid are glycine and lne Glycine and alanine are the example of simple amino acid glycine is being the simplest amino acid among all the 22 the simplest amino acid is glycine when it comes to alanine alanine is the most abundant amino acid that is found in the body most abundant amino acid that is found in the body is Allen so these are the two simple amino acid that we have coming to the second subcategory the second subcategory is the branch chain amino acid Branch chain amino acid means that the R Group is replaced by a branch carbon chain our group is replaced by a branch carbon Gene that is called as Branch chain amino acid the examples are leucine isoleucine and valine leucine isolation in willing they are the branch in amino acid how we can remember we can remember via pneumonic that is if you want to have a branch relationship if someone wants to have a branch huge branched relationship the person has to have a specific characteristic that the person has to be light-hearted the person has to be live at it so what I can say is to have the branch relationship to have the branch relationship the person has to be light-hearted the person has to be light-hearted you've seen isoleucine and valine l i v to have Branch relation the person has to be live at it the Third subcategory is the sulfur containing amino acid sulfur containing amino acid means that the R Group is replaced by sulfur there is sulfur in that R group that is called a sulfur containing amino acid the examples are me tuning and 16. material and cysteine are the sulfur containing amino acids so it'll remember it methionine and cysteine uh we can remember like this meaty cyst meaty means sweet what is there inside the meaty cyst it is the sulfur what is there inside the methiasis it is sulfur meaty cyst the fourth subcategory the fourth subcategory it is the hydroxyl group containing amino acid hydroxyl means alcohol a o h o h means the hydroxyl hydroxyl group or the alcohol group containing aminas alcohol group containing aminas hydroxyl group containing amino acid the examples are the examples are serine serine and threon these are the examples how we can remember is uh pneumonic is in Hindi so if you know Hindi it's very good if not fine you can remember it directly it's a hydroxyl group containing amino acids sir Tarot this is alcohol Siro this is alcohol sirotero means stop sir tarot this is alcohol that is serine these are the two amino acid which contains the hydroxyl group but there is one more amino acid apart from these two there is one more amino acid which also contains the hydroxyl group but there is certain characteristic difference between these two and the third one right so that is why I have not uh told that earlier I told that hydroxine group containing you need to remember two serine and the only there is one more and that is having some different characteristic let's first write down the name of that amino acid the name of that amino acid is tyrosine tyrosine also contains the hydroxyl group ribosin also contains the hydroxyl group right but let's write down this full statement tyrosine also contains hydroxyl group but it is water insoluble but it is water insoluble now what is the meaning of that see usually what happens is that the alcohol containing amino acid are water soluble we can easily understand that alcohol is water soluble so wherever there is alcohol that is going to be water soluble so the alcohol containing of innocent are motor soluble usually and that is saline tyrosine despite it contains a hydroxyl group but it is not water soluble that is why we are writing that in a separate line so the alcohol containing serine 300 tyrosine tyrosine we are writing a separate line because it's hydrophobic it is not water soluble coming to the fifth subcategory that is the acidic amino acid IC amino acid we can write acid like coh we can write acid like c o o h or we can write like C O O Negative right the point I want to convey to you is that wherever there is excess amount of acid it may contain with charge it will contain which charge negative charge because you write coh or Co negative same so whenever there is excess amount of acid it is going to contain negative charge so it is the these are the negatively charged amino acid the examples of the acidic amino acid are as part 8 and glutamate aspartate and glutamine the other names of these aspartame glutamate is aspartic acid and glutamic acid because when the examiner will try to ask you that which are which of the following is actually amino acid they will not give you the name aspartic acid or glutamic acid because name itself is very clear so they will use the alternate names aspartic acid also called as asparty glutamic acid also called as glutamate these are the acidic amino acid the sixth subcategory is amide group containing amino acid amide group containing aminas a Mite group containing amino acid so to understand a might do containing amino acid first we need to understand that what is the meaning of amide Robious what is the meaning of when I say it sulfur content is very obvious that it is containing s when I said hydroxyl group we know it is o h when I am saying that is amide group containing first we need to see what is the amide group is see the amide group is co nh2 this is referred as the Amigo so we need to look for the amino acid which contains this Amino this amide group has a tendency that it loves the acid let's understand it here what I'm saying is that the amide group has a tendency that it loves the acid wherever there is excess amount of acid this amide will go and will attach on that just prior to this we were discussing about the acidic amino acid acidic amino acid means that they have the excess amount of acid so we have two amino acid which have excess amount of acid aspartate and glutamine and right now I am saying that the amide has a tendency or Affinity towards the acidic amino acid so what is going to happen is that this amide is going to attach on the aspartate as well as it will go and will attach on the glutamine so the example when it comes to the example of a Mind Group containing amino acid I can see that amide will go and will attach on aspartate it will make a molecule that is called aspar Gene if amide goes and attaches some glutamate it will make the molecule that is with the name of glutamine so we have understood that the amount group containing amino acid we have to the aspergine and glutamine then the the last subcategory I can see is the seventh one is the basic aminas basic amino acid basic means the I can say they have the excess amount of Base when I set the acidic acidic are having which charge negative charge if acid is negatively charged the opposite base is going to have a charge is going to be having the positively charged amino acid so I can say basic amino acid or positively charged aminas positively charged aminus the examples are histidine lysine and arginine these are the basic amino acid histidine lysine Arginine how we can remember is with the simple mnemonic his last urge is very basic his last hours is very busy whenever whenever it comes to Last Wish it's going to be very basic only his last urge is very basic among these three if they ask that which is most basic which is having the highest page the answer is going to be Arginine arginine is having the highest pH or in other words I can say most basic in other words I can say most we see so these are the the seven subcategories of the amino acid based on their album based on their R group right simple branching sulfur containing hydroxyl group containing acid base and amide these are the seven categories the next classification that we are going to discussed the next classification that we are going to discuss is based on water solubility or I can say whether the amino acid is water soluble or not right so we are going to discuss the next classification based on the uh the the property of the amino acid whether it is water soluble or not right so let's write down the second type of classification that is based on water solubility water solubility based on that we can divide the 22 amino acid into two categories one is the water soluble that is the hydrophilic category and the hydrophobic category hydrophilic and hydrophobic hydrophilic they are also referred as Polar amino acid polar amino acid or hydrophilic is same polar or hydrophilic is seen when it comes to the the polar amino acid when it comes to the polar amino acid how we are going to remember them see we are not going to remember the entire list by all the examples of polar amino acid We Will Remember by the categories see how we are going to do that if I ask you in a simple way that whether the alcohol is water soluble or not means the whiskey the Vodka they are water soluble or not yes you will see yes they are water soluble so I can say that wherever there is alcohol it's going to be water soluble right so the alcohol containing amino acid they are going to be water soluble and we have written saline and three units this is alcohol serine threonine they are water soluble right so alcohol containing amino acid water soluble if I ask you acid is water soluble or not yes acid is water soluble because it contains charge in the same way basic amino acid they also contain shafts they are also going to be water soluble and there is a molecule which loves the acid that is amide right so wherever there is amide means there is acid and that is going to be water soluble so I can say that there are four categories which are going to be water soluble one is alcohol the second is acid base and Amite these are the water soluble amino acid that we have so if I write that the polar amino acid what are the polar amino acid we have uh we have the four subcategories alcohol acid base and amide these polar amino acid can further be divided into two subcategories two subcategories that is charged polar amino acid charged polar amino acid means having a charge or uncharged polar uncharged polar amination when it comes to the charged polar amino acid a Charged polar amino acid there are two examples that you have to add one is the acidic amino acid and the second is the BC combination because we know that acid is having negative charge whereas the basis B's are having the positive charge the acidic amino acid the examples are we know it's the aspartate and the glutamate that is the SD Gambino acid the basic amino acid we have written that the mnemonic was his last urge so histidine lysine Arginine they are the basic Amino state so charge the polarity they say it is going to be acid and base if this uncharged but polar uncharged but polar then the examples are going to be if they see uncharged but polar the examples are going to be the amide group containing amino acid a might group containing amino acid and they are the aspergine and the glutamine aspergine glutamine if they say uh the then the second category we can say is the alcohol containing amino acid they are also polar amino acid alcohol containing amino acid the examples are series and thrilling if you scroll up the nodes and you see the fourth subcategory that we have discussed in the classification of amino I said I told you that alcohol containing we have three serine three and tyrosine we have written tyrosine in a separate line the reason for that is because despite tyrosine contain hydroxyl group it is not water soluble that is why we have written that in a separate line so these are the the polar amino acid when it comes to charged category acid base when it comes to uncharged categories the amide and alcohol containing apart from these four categories apart from these four categories there are two more amino acid which are water soluble their entire category is not water soluble but they individually they are water soluble so they will come under the category of uncharged polar apart from these we have two more amino acid which are water soluble and that is glycine and cysteine glycine is a simple amino acid and the the cysteine is a sulfur containment amino acid the entire category is not water soluble but these two are water soluble these two are water soluble so this is the complete classification of the the hydrophilic amino acid if they say what are the four categories acid-base amide and alcohol apart from these four which are two individual amino acid which are water soluble Glycine and cysteine remaining all remaining all are hydrophobic so when it comes to hydrophobic I can see remaining wall remaining all are hydrophobic so this is the classification of amino acid based on water solubility whether they are water soluble or not now here are some controversial questions so how to answer them there is some controversial part that is there in this hydrophobic water solubility so I will try to give you a best idea that what is the best possible choice that you can select in a multiple choice question if we see that which is the most water soluble if we see the most Hydro philic amino acid the most hydrophilic amino acid that we have is arginine it is the most hydrophilic most hydrophilic in the hydrophilic category there are some other examples we have discussed them right so when you reach to the bottom the least water soluble among the water soluble category means having the the least uh characteristic of having water solubility among the water soluble is glycine so these are the hydrophilic amino acid that we have when it comes to the hydrophobic when it comes to the hydrophobic the least hydrophobic among the hydrophobic category is tyrosine then there are several examples and then we'll reach all the way bottom that is isoleucine which is the most most hydrophobic most hydrophobic is isolation so this is the order this is the order that arginine is the most water soluble the least water soluble is isoleucine and somewhere in between we are going to have the Glycine and tyrosine on the borderline where they are going to meet right so glycine is the least water soluble in the water soluble category if you take all the water soluble oil which is having least water solubility among the that four is going to be glycine and if you see that the in among all the hydrophobic in among all the hydrophobic which is having the maximum potential to be a water uh hydrophilic amino acid the answer will be Titus in that this tyrosine can go to the upper category also so this is the gray area this is the gray area so when the quotient will be asked from this particular part then you have to select the answer based on the given option based on the given option say for example if I ask you that all of the following are water soluble except if the quotient language is like that all of the following are water soluble except and the three options are Arginine Glycine tyrosine and let's say someone is from here or may be isolation right so which one you are going to choose you are going to choose this one you are going to choose this one right if they have given three options if they have given three options from like that see here the first option is Arginine then one option is from here let's say sari the third option is glycine and the fourth option is tyrosine if these are the four options and they're asking that which is water insoluble then the the answer is very straightforward is going to be diagnosing right so depending on option you have to choose from this particular gray area so this is uh one controversial part and this is how you have to find the answer in that controversial part this is the second classification that is based on the water solubility the the third type of classification that we are going to discuss is based on the metabolism based on metabolism of amino acid when you do the metabolase what you are going to notice that when you metabolize these various 22 types of amino acid you are going to notice that we can get several types of metabolite and one of them is Ketone body if you generate Ketone body from the amino acid metabolase such amino acid are called as ketogenic amino acid they are called as ketogenic amination there are some amino acids which can generate glucose on their metabolism they are referred as glucogenic amination the other food is glycogenic amino acid so we have ketogenic amino acid we have glucogenic Amino there are some amino acids which can generate Ketone body and glucose both depending whatever is the demand of the body either body requires Ketone body they will generate Ketone if the body requires glucose they will make glucose so they are called as keto Plus glycogenic keto plus so I can say that there are three subcategories based on the metabolism of amino acid it can be ketogenic keto plus glucose and the glucagogenic keto keto plus glucose and the glucagogy when it comes to the example of ketogenic amino acid there are two examples to be remembered one is leucine leucine is the most ketogenic amino acid among all the ketogenes the most ketogenic most ketogenic is Lucy then the second we can add is lysine which is also predominantly ketogenic so leucine and lysine they are ketogenic but among these two if you have to select one which is most ketogenic the answer is leucine the answer is Lucy when it comes to keto plus glucogenic keto plus glucagogenic the examples are tryptophan phenylalanine tyrosine and isolation these are the four amino acid which are keto plus glucogenic means they can make ketones as well as glucose depending on the demand the third category is the glucogenic amino acid so I can say in the example of glucagogenic ambient acid is the remaining all the amino acid are glycogenic remaining all the 16 amino acids are glucosamic but if they ask that which is most glucagogenic among the remaining ones which is the the most leukogenic is alanine most glucogenic the answer is lnn so most ketogenic leucine most uh glucagogenic is so this is the second classification that is at the third class region that is based on the metabolism that is based on the metabolism amino acid ketogenic keto plus glucose and the glucogenic the fourth classification of amino acid the fourth classification of amino acid that is based on the nutritional requirement classification based on nutritional requirement classification amino acid based on nutrition requirement the subcategory you may have heard about them earlier also the based on nutritional requirement the amino acids are classified into three categories classified into three categories the essential semi-essential and the knowledge essential semi-essential and monosition these are the uh the amino acid categories based on the nutritional requirement what is the meaning of essential essential means that these are the amino acid you have to take them in your diet the body cannot synthesize them endogenously they are called as essential non-essential means whether you eat in your diet or not the body is going to synthesize them endogenously they are non-essential whether you take them in your diet or not the body will take care of that that are non-essential now the semi-essential amino acid are those amino acids which are required during the time of growth means when we were in the Pediatric age group during the time of growth the these amino acid are required they are come under the category of semi engine so there are three categories essential semi essential and normalization so let's see the examples of essential amino acid when it comes to the essential amino acid first we need to remember that there are nine amino acid there are nine amino acid which are essential we have nine essential amino out of 22 we have nine are essential when it comes to the mnemonic for which are the essential amino acid we have the mnemonic that we are going to use is TV till 9 pm H TV till 9 pmh TV till 9 pmh is the example for the nine essential amino acid for example if I say isolucine is it essential or not you will see the initial isoleucine is I and you will search whether the eye is there in the mnemonic or not yes I is there so you will save it in the same way what they do is they will try to confuse you between three options between three options say if I see the amino acid the set of 22 I mean I said what I am going to notice that there are three amino acid that starts with the letter t if I ask you that which amino acid starts with the letter t you will say tryptophan cryptofan yes it is and the tyrosine these are the three amazing amino acid that starts with the letter t now if they ask that which are the essential amino acid and these are the option these are the options so you will use the mnemonic TV till 9 pmh if you see the mnemonic how many T's are there there is one t TV till so again one more T so there are two t but how many amino acid starts with the letter D crypto fan creonine and the tyrosine so this thyrosine starts with the letter t it is non-essential it is non-essential so we need to remember Z The Examiner knows that you are going to use the numer activity till 9 pmh so they will try to confuse you between tryptophan threonine and the tyrosine so we should know that tyrosine is a non-essential amino acid if you are using this mnemonic the thing that has to always keep always have to be kept in mind is that the tyrosine is non-essiation so I am writing this statement here is tyrosine is small essential if you remember these three things nine essential we have TV till 9 pmh tyrosine is non-efficient all the mcqs are going to be correct when it comes to the category of essential amino acid right if you want to write all the nine names all the nine names what are the TV till nine pmh what are the nine names are you can see in the list here these are the nine essential amino acid we have these are the in essential amino acid so you can see is the tryptophan valine threonine isolucine leucine lysine phenylene methionine and histidine tyrosine is non-essential thyrosine is nonstation right so uh in some books in some bugs you might find histidine is not written in essential in some books it might be written in semi essential category semi essential category so that is again we can say a controversial part I will tell you how to solve such McQ also right so the essential category the essential category initially we will we will have this concept that we will retain the histidine in the essential category only and the mnemonic is going to be TV till the npmh types acidine is a controversial part some book says it may consider a semi essential right when we see the negative nitrogen balance then we find that histidine is not the semi essential it is the essential amino acid but still in some books it is written as simulation so we will always have to keep that thought in our mind while solving the McQ so these are the essential amino acid that we have now coming to the semi-essential categories in the semi-essential category the only example that we have to remember in mind is Arginine the only example is arginine that we have to keep in mind the third category is non-essential the examples are remaining all the 12 amino acid remaining all 12 amino acid are going to be non-essential so we have the the essential semi essential non-essiation we have the essential semi essential non-essential there is a controversial part regarding the history in some books it is essential in some books it is semi essential so when you are solving the McQ and they are asking that which of the following is semi-ass changes let's say which of the following is semi-essential and in that quotient arginine is not given in the choice instead of arginine histidine is going in the choice then you will selected in a semi extension right so it all depends on the options that are given to you depending on that we have to find the best option so as I told you as example that if they say which of the following is semi essential arginine is not in the option then the second best answer is history right this is the the fourth classification that is based on the nutritional requirement the next thing is there are uh this is the this is the fourth category of classification that is completed then there is a special property of amino acid that some amino acid have a specific order or a specific smell right these are called as aromatic amino acid so this is a ectopic variety we can say is the aromatic amino acid means they have a peculiar order or a peculiar smell they are called as aromatic amino acid so what is important is to remember is the example what are the example of aromatic amino acid we have so to remember the aromatic amino acid I will just tell you a simple mnemonic how to remember the aromatic amino acid for example let's say right now we are having this class in a closed environment let's say all the closed all the doors all the windows are closed now what I do is uh I bring a rubber tire in this classroom and I burn the tire I burn the tire now what is going to happen is after some time everywhere there will be smoke of this burn Tire everywhere there will be smell of this burn time to get rid of the smell what you need to do is you need to turn on the fan so that the you will turn on the exhaust fence so that this smog will go out the smell will go out so the point is that wherever we have smell wherever we have smell what you have to do you have to turn on the fan wherever they smell you will have the fan wherever they smell you have the fat so the aromatic amino acid are those amino acid which contains fan in their name amino acid which contains fan in their name this is just a way to remember so the aromatic amino acid are those which contain fan in the name the examples are cryptofan the example is crypto fan you can see fan in the name one more example again phenyl Ln again fan in the knee so whenever is fan in the name it's aromatic what was the smell what you have burned what you have burned in the classroom that was tired so tylosine is also aromatic amino acid so tyrosine is aromatic amino acid apart from these the fourth one is history history that is also aromatic so the firstly you can easily Remember by the new money what is the smell this time tryptophanic the fourth one is histidine these are the aromatic amino acid we have so this is a ectopic variety of amination there is one more ectopic variety of amino acid and that is referred as derived aminas derived amino acid let's understand what is the meaning of derived amino acid so to understand that their definition of rewrite amino acid I will just use a simple concept that see the most of the amino acid most of the amino acid say for example methionine it is represented by a codon every amino acid will be represented by a codon the codon for methionine is Aug we'll discuss that in detail when we will discuss genetic code right but for now every amino acid is represented by a codon and for methion in the codon is aug but there are some amino acid which cannot be represented by a codon if amino acid cannot be represented by your codon that is called as derived amino acid that comes under the category of derived amino acid so what is deridamina said amino acid which cannot be represented which cannot be represented by codon that is referred as the derived amino acid usually the amino acid is the represented by a codon but if amino acid cannot be represented by codons called as desired amino acid so what is important is the example the example of derived amino acid the first example is hydroxy Proline hydroxy poly this is found in collagen found in collagen protein collagen is a protein the hydroxyproline is found in collagen then is the hydroxy lysine hydroxylizine that is also desired Amino Acid found in collagen then the next example is desmosine it is found in elastin then the fourth example is cystine this time the sustained molecule should not be confused with cysteine cysteine we have discussed earlier system we have discussed earlier what is cysteine is cysteine is a solve for cutting amino acid so what is cystine and what is system what is the difference between them so what I do is we know that cysteine is a sulfur containing amino acid what I do is I take two molecules of system let's say this is the first molecule and this is the second molecule of cysteine I take two molecules of the steam I joined these two cysteine molecule between by these two sulfur molecules so this is the bond that I am going to have is the di sulfide Bond disulfide Bond so if you take two system molecule joint via the disulfide bond this entire unit that you have got is going to be referred as cystine this entire unit that you got is referred as cystine right so what they ask is this stain is found where cystane is found in those molecule which contains disulfide Bond wherever we require disulfide Bond we will place cystine molecules because we know that cystine is having disulfide mode so the example where it is found is found in insulin insulin protein contains a disulfide bond so that we require system one more example that I can add is immunoglobulin that is antibodies that also requires cystine molecule insulin and immunoglobulin they require the cystine molecule the other examples of the derived amino acid so we have discussed four examples of delight amino acid hydroxyproline hydroxylizine desmosine and cystine few more examples that I can add is ornithin [Music] citrulline or anything these are the uh the other examples of the derived getting right so there are many others also but at least you should remember these six at least you should remember these six these are the six amino acid which are uh the derived amino acid so this is the complete classification of amino acid this is complete classification we have divided the amino acid base mainly in four subcategories based on our group then based on the the water solubility then we have discussed about the based on the their metabolismogenic then we have discussed about the nutritional requirement essential semi essential non-essential then there are two special properties one is the derived amino acid and the uh the aromatic amino acid one point I forgot to mention about the aromatic amino acid that you can write in the aromatic amino acid if I just scroll up the thing uh the nodes we have written that in the aromatic amino acid there are four examples tryptophan phenylalanine and tyrosine and distillate you can write there is one more point that you can write is aromatic amino acid has a tendency to absorb the UVS they have a tendency to absorb the UV rays when you place these amino acid in the sunlight sunlight contains UV rays so these amino acid will absorb the UVs among these four this uh among these four the tryptophan is having the maximum absorption of the UV rays so you can write this point here that all the aromatic amino acid have a tendency to absorb UV rays maximum UV absorption maximum UV absorption is seen with tryptophan this was asked in the exam earlier that which amino acid has the maximum tendency to absorb the UVS the answer is going to be tryptophan right so all the aromatic have a tendency to absorb the urase the maximum is with the the maximum is with the tryptophan maximum is with the tryptophan so this is the complete classification of the amino acid because as I saying that earlier we have only 20 types of amino acid now we have added the 21st and the 22nd amino acid so we should know few details regarding them one is the 21st amino acid the 21st Amina said the name of the 21st amino acid is selenocystein Salon 60 if they ask that what is the codon we do not have to remember all the codons we have to remember only three columns one I already told to you mithyanin that is the AUG the codon for Salon system is u g a if they ask that what is the the precursor precursor amino acid means cellular cysteine is synthesized from which amino acid what is the precursor the precursor is Siri saline will convert ultimately into cellular system so the precursor amino acid is Siri is Siri when it comes to the 22nd amino acid 22nd amino acid the example of 22nd amino acid is the name of the 22nd amino acid is pyrolysis pyrolysis the codon for pyrolysine is UAG there is no as such precursor for pyrolysis so these are the details to be remembered for 21st and 22nd Amino say 21st is 7 16 22nd is spiralizing 22nd is spiralizing so once we are uh completed once we have completed this entire classification centers is a very important topic there is going to be one question for 100 from one question from the this discussion of the classification of amino acid

foreign [Music] have four valencies if I just make a basic structure we know that the carbon have four valencies if on one of the evaluency we are having the amino group that is nh2 one of the valency we are having the amino group the another valency we are having the acid group at the same time we are having the amino group acid group at the same time Amino means nh2 adding means coh if you are having same uh at the same time we are having the amino capacity group that is called as amino acid the third valency is hydrogen and the fourth valency can be anything so I am writing R it can be sulfur it can be alcohol it can be anything so I am writing R so this is a basic structure of amino acid this is a basic structure of amino acid amino group acidic group at the same time is aminas what is the third valence is going to be hydrogen fourth can be anything so I am writing R so what is r r means it can be any group it can be any group it can be hydrogen it can be carbon it can be carbon chain sulfur it can be anything so I&#39;m writing r so once we are clear with this basic structure of amino acid now what we need to understand is few definitions uh that will make a base for this chapter of amino acid right so let&#39;s starting with the first definition that we should know is Alpha amino acid help amino acid so to understand this Alpha amino acid we need to understand that what is the meaning of alpha right so to make you understand that I am taking a just simple example let&#39;s say this is a carbon chain and having the carboxylic acid as a functional group right so if I want to do the carbon numbering we always start the carbon numbering from the functional group so uh here is the function group so we&#39;ll start with the carbon domain from here is carbon number one two three four and so on right this is one of the way of doing carbon numbering the other way of doing carbon numbering is that the carbon which is next to the function group say this is the functional group the carbon which is next to the function group is referred as the alpha carbon then the beta carbon Gamma Delta and so on right so what we have understood by this example is that what is Alpha carbon is Alpha carbon means the carbon which is next to the functional group carbon which is next to the functional the carbon which is next to the function group is referred as Alpha carbon if we apply the same concept of alpha Carbon on the amino acid on the amino acid then what we are going to appreciate is see this is the the carbon having four valencies one valence is having amino group another valency is having acidic group the third valence is hydrogen the fourth is can be anything from adding R so this is a structure of amines structure of amino acid because here is the main function group that is the coh then the carbon next to the function Loop the carbon which is next to the function group is going to be the alpha carbon it&#39;s going to be the alpha carbon in this Alpha carbon you can easily appreciate that this amino group is right now attached right now attached to the alpha carbon in this amino acid the amino group is right now attached to the alpha carbon so this is referred as Alpha amino acid this is referred as so this is referred as the alpha amino acid referred as Alpha amino acid so what is Alpha amino acid is that amino group is attached to the alpha carbon so let&#39;s write down the definition of alpha amino acid that the amino group amino group is attached to Alpha carbon if the amino group is attached to the alpha carbon that is referred as the what what happens in our body is that the most of the amino acid are found in Alpha for most of the minister are found in Alpha form there are some exceptions there are some amino acid which is not found in the alpha form and this is what we need to know so the exceptions to the alpha minus it means the amino acid which is not found in the alpha form exceptions to the alpha amino acid say they are beta linen beta alanine betaalanine the name itself is very clear that the amino group is attached to the beta carbon that&#39;s betal in it one more uh exception that we can add is beta Amino isobutyrate beta Amino isobutyrate gamma Amino isobutyrate so the name itself is very clear that we have a prefix that beta Island in beta amino acid rate gamma Amino isobitrate that the amino group is not attached to the alpha curve so this is the first definition that we need to remember in respect of the amino acid that is Alpha with acid let&#39;s understand the second definition that is with the name of kerial carbon carbon now what is the meaning of kerial carbon is if we know that carbon have four valencies carbon have four valencies if all the four valencies are having different functional group for example here it is X y z a what you can appreciate is all the four valances are different if all the four valencies are different then such carbon is referred as kerial carbon this is referred as kirial carbon is all the four valencies all the four valencies having different functional group leaving different function group or different atoms that is reference now why this serial carbon is important see you may have heard that something called as there is something called as Mirror Image there is something called as mirror image or the optic isomers mirror image or the optic isomers if we want to make a mirror image of any molecule the mirror image or the optical activity depends whether the molecule contains aerial carbon not if the molecule does not contain a kerial carbon then the mirror image is not possible so is only possible if a molecule contains kirial carbon if the molecule does not contain carbon the mirror image is not possible so using this information if I apply this concept here on this structure of uh amino acid here is the amino group the acid group so this is going to be amino acid the third valency is hydrogen let&#39;s see the fourth valency is also hydrogen so what you can appreciate is third and fourth valency are same because two valencies are same so I can say it is not a kerial carbon it is not a keryl carbon now once it is not a kerial carbon once it is not carbon but at the same time it is having the amino group acidic group so it is amino acid the name of this amino acid is glycine so what they ask is which amino acid does not contain girdle carbon that is a straightforward question the answer is going to be glycine or in other way they can ask this that which amino acid is optically inactive means which cannot make the middle image the answer is going to be glycine because it does not contain the cheerle carbon so let&#39;s write down this point that glycine does not contain keryl carbon hence it is optically inactive glycine does not contain keryl carbon hence it is optically inactive does not contain kale carbon so it is optically inactive this is the second definition the third definition that we should know is the third definition that we should know is amino acid so we have discussed about alpha mean acid and the kidial carbon the third that we are discussing is immunizing if I make the structure of amino acid carbon having four valencies on one of the valency we are having the amino group The acidic group the hydrogen and the fourth valency can be anything so hydrating r now here what you can appreciate is that the amino group is free p in the sense that it can make bond with the nearby amino acid it can make peptide bond with a nearby amino acid it is currently free this amino group is free but what I do is if I alter the structure of the amino group means right now this amino group is free but now what I do is I bound this amino group in a ring structure like this now you can see that I have made a ring around the amino group right this amino group is not free if the amino group is not free then this molecule is referred as amino acid referred as amino acid so what is amino acid that the amino group is not free is not free instead it is bound in a ring structure if the amino group is not free Bound in the ringing structure is therefore as amino acid what is very important is that what is the example of amino acid the example of amino acid is Proline Proline is the example of amino acid it does not have the free amino group sometimes they might ask that what is the name of this ring what is the name of this ring the name of this ring is this is referred as pyro leading ring so pylolidian ring is found in which amino acids found in Broly which is an example of immunize so these are the three definition to be remembered right so to summarize what we have discussed that the first thing that we need to know is the alpha amino acid in humans most of the amino acid are found in Alpha there are few exceptions and the most important exception that you should know is beta alanine now when they will ask this question they will not write this beta word in the options the reason is if they write beta then it&#39;s going to be very obvious right so the beta word they will remove they will just write Ln in Ln is the example of beta beta amino acid the the second thing that we have discussed was the kerial carbon kirial carbon or the optical activity so the point to be remembered is real carbon not found in which amino acid the only amino acid is glycine which does not have the kirial carbon it is optically inactive the third thing that we have discussed was amino acid the example of amino acid is very important is Proline the amino group is not free is bound in a ring structure so these are the three points to be remembered from this definition part now coming to the very important part of the chapter amino acid and that is in respect of the classification of amino acid classification of aminas so to do the classification of any group first we need to understand that how many amino acid we have earlier we have 20 types of amino acid now recently two more amino acid are added and now we have total 22 types of amino acid we have 22 types of amino acid and we need to classify these 22 group uh 22 amino acid so to classify any group any group say for example if we are having right now 22 student in the classroom and I want to classify these 22 students so what I can do is I need to have a basis on what ground I am going to do the classification say for example I can do the classification on the basis of your age 21 22 year 23 year 24 year and so on I again classified on the basis of your let&#39;s say the native state and so on right so on the basis of various thing we can classify the groups so the here also we want to classify the amino acid so first we need to understand that on what ground we are going to do the classification right so the first classification that we are going to discuss is based on the R group based on R Group what is R Group R Group is basically the side chain if I make the structure of amino acid that we have made earlier is the amino group LCD group hydrogen the four volts are the fourth valency was r as I told you earlier that R can be anything it can be hydrogen it can be uh carbon it can be sulfur alcohol it can be anything so based on that we are going to do the classification so the first subcategory the first subcategory if we do the classification that is based on the R Group the first subcategory comes out to be simple amino acid simple amino acid means that the R Group is replaced by either a simple hydrogen or by a simple carbon if you replace the R Group with simple hydrogen or carbon that is called a simple amino acid the example of simple amino acid are glycine and lne Glycine and alanine are the example of simple amino acid glycine is being the simplest amino acid among all the 22 the simplest amino acid is glycine when it comes to alanine alanine is the most abundant amino acid that is found in the body most abundant amino acid that is found in the body is Allen so these are the two simple amino acid that we have coming to the second subcategory the second subcategory is the branch chain amino acid Branch chain amino acid means that the R Group is replaced by a branch carbon chain our group is replaced by a branch carbon Gene that is called as Branch chain amino acid the examples are leucine isoleucine and valine leucine isolation in willing they are the branch in amino acid how we can remember we can remember via pneumonic that is if you want to have a branch relationship if someone wants to have a branch huge branched relationship the person has to have a specific characteristic that the person has to be light-hearted the person has to be live at it so what I can say is to have the branch relationship to have the branch relationship the person has to be light-hearted the person has to be light-hearted you&#39;ve seen isoleucine and valine l i v to have Branch relation the person has to be live at it the Third subcategory is the sulfur containing amino acid sulfur containing amino acid means that the R Group is replaced by sulfur there is sulfur in that R group that is called a sulfur containing amino acid the examples are me tuning and 16. material and cysteine are the sulfur containing amino acids so it&#39;ll remember it methionine and cysteine uh we can remember like this meaty cyst meaty means sweet what is there inside the meaty cyst it is the sulfur what is there inside the methiasis it is sulfur meaty cyst the fourth subcategory the fourth subcategory it is the hydroxyl group containing amino acid hydroxyl means alcohol a o h o h means the hydroxyl hydroxyl group or the alcohol group containing aminas alcohol group containing aminas hydroxyl group containing amino acid the examples are the examples are serine serine and threon these are the examples how we can remember is uh pneumonic is in Hindi so if you know Hindi it&#39;s very good if not fine you can remember it directly it&#39;s a hydroxyl group containing amino acids sir Tarot this is alcohol Siro this is alcohol sirotero means stop sir tarot this is alcohol that is serine these are the two amino acid which contains the hydroxyl group but there is one more amino acid apart from these two there is one more amino acid which also contains the hydroxyl group but there is certain characteristic difference between these two and the third one right so that is why I have not uh told that earlier I told that hydroxine group containing you need to remember two serine and the only there is one more and that is having some different characteristic let&#39;s first write down the name of that amino acid the name of that amino acid is tyrosine tyrosine also contains the hydroxyl group ribosin also contains the hydroxyl group right but let&#39;s write down this full statement tyrosine also contains hydroxyl group but it is water insoluble but it is water insoluble now what is the meaning of that see usually what happens is that the alcohol containing amino acid are water soluble we can easily understand that alcohol is water soluble so wherever there is alcohol that is going to be water soluble so the alcohol containing of innocent are motor soluble usually and that is saline tyrosine despite it contains a hydroxyl group but it is not water soluble that is why we are writing that in a separate line so the alcohol containing serine 300 tyrosine tyrosine we are writing a separate line because it&#39;s hydrophobic it is not water soluble coming to the fifth subcategory that is the acidic amino acid IC amino acid we can write acid like coh we can write acid like c o o h or we can write like C O O Negative right the point I want to convey to you is that wherever there is excess amount of acid it may contain with charge it will contain which charge negative charge because you write coh or Co negative same so whenever there is excess amount of acid it is going to contain negative charge so it is the these are the negatively charged amino acid the examples of the acidic amino acid are as part 8 and glutamate aspartate and glutamine the other names of these aspartame glutamate is aspartic acid and glutamic acid because when the examiner will try to ask you that which are which of the following is actually amino acid they will not give you the name aspartic acid or glutamic acid because name itself is very clear so they will use the alternate names aspartic acid also called as asparty glutamic acid also called as glutamate these are the acidic amino acid the sixth subcategory is amide group containing amino acid amide group containing aminas a Mite group containing amino acid so to understand a might do containing amino acid first we need to understand that what is the meaning of amide Robious what is the meaning of when I say it sulfur content is very obvious that it is containing s when I said hydroxyl group we know it is o h when I am saying that is amide group containing first we need to see what is the amide group is see the amide group is co nh2 this is referred as the Amigo so we need to look for the amino acid which contains this Amino this amide group has a tendency that it loves the acid let&#39;s understand it here what I&#39;m saying is that the amide group has a tendency that it loves the acid wherever there is excess amount of acid this amide will go and will attach on that just prior to this we were discussing about the acidic amino acid acidic amino acid means that they have the excess amount of acid so we have two amino acid which have excess amount of acid aspartate and glutamine and right now I am saying that the amide has a tendency or Affinity towards the acidic amino acid so what is going to happen is that this amide is going to attach on the aspartate as well as it will go and will attach on the glutamine so the example when it comes to the example of a Mind Group containing amino acid I can see that amide will go and will attach on aspartate it will make a molecule that is called aspar Gene if amide goes and attaches some glutamate it will make the molecule that is with the name of glutamine so we have understood that the amount group containing amino acid we have to the aspergine and glutamine then the the last subcategory I can see is the seventh one is the basic aminas basic amino acid basic means the I can say they have the excess amount of Base when I set the acidic acidic are having which charge negative charge if acid is negatively charged the opposite base is going to have a charge is going to be having the positively charged amino acid so I can say basic amino acid or positively charged aminas positively charged aminus the examples are histidine lysine and arginine these are the basic amino acid histidine lysine Arginine how we can remember is with the simple mnemonic his last urge is very basic his last hours is very busy whenever whenever it comes to Last Wish it&#39;s going to be very basic only his last urge is very basic among these three if they ask that which is most basic which is having the highest page the answer is going to be Arginine arginine is having the highest pH or in other words I can say most basic in other words I can say most we see so these are the the seven subcategories of the amino acid based on their album based on their R group right simple branching sulfur containing hydroxyl group containing acid base and amide these are the seven categories the next classification that we are going to discussed the next classification that we are going to discuss is based on water solubility or I can say whether the amino acid is water soluble or not right so we are going to discuss the next classification based on the uh the the property of the amino acid whether it is water soluble or not right so let&#39;s write down the second type of classification that is based on water solubility water solubility based on that we can divide the 22 amino acid into two categories one is the water soluble that is the hydrophilic category and the hydrophobic category hydrophilic and hydrophobic hydrophilic they are also referred as Polar amino acid polar amino acid or hydrophilic is same polar or hydrophilic is seen when it comes to the the polar amino acid when it comes to the polar amino acid how we are going to remember them see we are not going to remember the entire list by all the examples of polar amino acid We Will Remember by the categories see how we are going to do that if I ask you in a simple way that whether the alcohol is water soluble or not means the whiskey the Vodka they are water soluble or not yes you will see yes they are water soluble so I can say that wherever there is alcohol it&#39;s going to be water soluble right so the alcohol containing amino acid they are going to be water soluble and we have written saline and three units this is alcohol serine threonine they are water soluble right so alcohol containing amino acid water soluble if I ask you acid is water soluble or not yes acid is water soluble because it contains charge in the same way basic amino acid they also contain shafts they are also going to be water soluble and there is a molecule which loves the acid that is amide right so wherever there is amide means there is acid and that is going to be water soluble so I can say that there are four categories which are going to be water soluble one is alcohol the second is acid base and Amite these are the water soluble amino acid that we have so if I write that the polar amino acid what are the polar amino acid we have uh we have the four subcategories alcohol acid base and amide these polar amino acid can further be divided into two subcategories two subcategories that is charged polar amino acid charged polar amino acid means having a charge or uncharged polar uncharged polar amination when it comes to the charged polar amino acid a Charged polar amino acid there are two examples that you have to add one is the acidic amino acid and the second is the BC combination because we know that acid is having negative charge whereas the basis B&#39;s are having the positive charge the acidic amino acid the examples are we know it&#39;s the aspartate and the glutamate that is the SD Gambino acid the basic amino acid we have written that the mnemonic was his last urge so histidine lysine Arginine they are the basic Amino state so charge the polarity they say it is going to be acid and base if this uncharged but polar uncharged but polar then the examples are going to be if they see uncharged but polar the examples are going to be the amide group containing amino acid a might group containing amino acid and they are the aspergine and the glutamine aspergine glutamine if they say uh the then the second category we can say is the alcohol containing amino acid they are also polar amino acid alcohol containing amino acid the examples are series and thrilling if you scroll up the nodes and you see the fourth subcategory that we have discussed in the classification of amino I said I told you that alcohol containing we have three serine three and tyrosine we have written tyrosine in a separate line the reason for that is because despite tyrosine contain hydroxyl group it is not water soluble that is why we have written that in a separate line so these are the the polar amino acid when it comes to charged category acid base when it comes to uncharged categories the amide and alcohol containing apart from these four categories apart from these four categories there are two more amino acid which are water soluble their entire category is not water soluble but they individually they are water soluble so they will come under the category of uncharged polar apart from these we have two more amino acid which are water soluble and that is glycine and cysteine glycine is a simple amino acid and the the cysteine is a sulfur containment amino acid the entire category is not water soluble but these two are water soluble these two are water soluble so this is the complete classification of the the hydrophilic amino acid if they say what are the four categories acid-base amide and alcohol apart from these four which are two individual amino acid which are water soluble Glycine and cysteine remaining all remaining all are hydrophobic so when it comes to hydrophobic I can see remaining wall remaining all are hydrophobic so this is the classification of amino acid based on water solubility whether they are water soluble or not now here are some controversial questions so how to answer them there is some controversial part that is there in this hydrophobic water solubility so I will try to give you a best idea that what is the best possible choice that you can select in a multiple choice question if we see that which is the most water soluble if we see the most Hydro philic amino acid the most hydrophilic amino acid that we have is arginine it is the most hydrophilic most hydrophilic in the hydrophilic category there are some other examples we have discussed them right so when you reach to the bottom the least water soluble among the water soluble category means having the the least uh characteristic of having water solubility among the water soluble is glycine so these are the hydrophilic amino acid that we have when it comes to the hydrophobic when it comes to the hydrophobic the least hydrophobic among the hydrophobic category is tyrosine then there are several examples and then we&#39;ll reach all the way bottom that is isoleucine which is the most most hydrophobic most hydrophobic is isolation so this is the order this is the order that arginine is the most water soluble the least water soluble is isoleucine and somewhere in between we are going to have the Glycine and tyrosine on the borderline where they are going to meet right so glycine is the least water soluble in the water soluble category if you take all the water soluble oil which is having least water solubility among the that four is going to be glycine and if you see that the in among all the hydrophobic in among all the hydrophobic which is having the maximum potential to be a water uh hydrophilic amino acid the answer will be Titus in that this tyrosine can go to the upper category also so this is the gray area this is the gray area so when the quotient will be asked from this particular part then you have to select the answer based on the given option based on the given option say for example if I ask you that all of the following are water soluble except if the quotient language is like that all of the following are water soluble except and the three options are Arginine Glycine tyrosine and let&#39;s say someone is from here or may be isolation right so which one you are going to choose you are going to choose this one you are going to choose this one right if they have given three options if they have given three options from like that see here the first option is Arginine then one option is from here let&#39;s say sari the third option is glycine and the fourth option is tyrosine if these are the four options and they&#39;re asking that which is water insoluble then the the answer is very straightforward is going to be diagnosing right so depending on option you have to choose from this particular gray area so this is uh one controversial part and this is how you have to find the answer in that controversial part this is the second classification that is based on the water solubility the the third type of classification that we are going to discuss is based on the metabolism based on metabolism of amino acid when you do the metabolase what you are going to notice that when you metabolize these various 22 types of amino acid you are going to notice that we can get several types of metabolite and one of them is Ketone body if you generate Ketone body from the amino acid metabolase such amino acid are called as ketogenic amino acid they are called as ketogenic amination there are some amino acids which can generate glucose on their metabolism they are referred as glucogenic amination the other food is glycogenic amino acid so we have ketogenic amino acid we have glucogenic Amino there are some amino acids which can generate Ketone body and glucose both depending whatever is the demand of the body either body requires Ketone body they will generate Ketone if the body requires glucose they will make glucose so they are called as keto Plus glycogenic keto plus so I can say that there are three subcategories based on the metabolism of amino acid it can be ketogenic keto plus glucose and the glucagogenic keto keto plus glucose and the glucagogy when it comes to the example of ketogenic amino acid there are two examples to be remembered one is leucine leucine is the most ketogenic amino acid among all the ketogenes the most ketogenic most ketogenic is Lucy then the second we can add is lysine which is also predominantly ketogenic so leucine and lysine they are ketogenic but among these two if you have to select one which is most ketogenic the answer is leucine the answer is Lucy when it comes to keto plus glucogenic keto plus glucagogenic the examples are tryptophan phenylalanine tyrosine and isolation these are the four amino acid which are keto plus glucogenic means they can make ketones as well as glucose depending on the demand the third category is the glucogenic amino acid so I can say in the example of glucagogenic ambient acid is the remaining all the amino acid are glycogenic remaining all the 16 amino acids are glucosamic but if they ask that which is most glucagogenic among the remaining ones which is the the most leukogenic is alanine most glucogenic the answer is lnn so most ketogenic leucine most uh glucagogenic is so this is the second classification that is at the third class region that is based on the metabolism that is based on the metabolism amino acid ketogenic keto plus glucose and the glucogenic the fourth classification of amino acid the fourth classification of amino acid that is based on the nutritional requirement classification based on nutritional requirement classification amino acid based on nutrition requirement the subcategory you may have heard about them earlier also the based on nutritional requirement the amino acids are classified into three categories classified into three categories the essential semi-essential and the knowledge essential semi-essential and monosition these are the uh the amino acid categories based on the nutritional requirement what is the meaning of essential essential means that these are the amino acid you have to take them in your diet the body cannot synthesize them endogenously they are called as essential non-essential means whether you eat in your diet or not the body is going to synthesize them endogenously they are non-essential whether you take them in your diet or not the body will take care of that that are non-essential now the semi-essential amino acid are those amino acids which are required during the time of growth means when we were in the Pediatric age group during the time of growth the these amino acid are required they are come under the category of semi engine so there are three categories essential semi essential and normalization so let&#39;s see the examples of essential amino acid when it comes to the essential amino acid first we need to remember that there are nine amino acid there are nine amino acid which are essential we have nine essential amino out of 22 we have nine are essential when it comes to the mnemonic for which are the essential amino acid we have the mnemonic that we are going to use is TV till 9 pm H TV till 9 pmh TV till 9 pmh is the example for the nine essential amino acid for example if I say isolucine is it essential or not you will see the initial isoleucine is I and you will search whether the eye is there in the mnemonic or not yes I is there so you will save it in the same way what they do is they will try to confuse you between three options between three options say if I see the amino acid the set of 22 I mean I said what I am going to notice that there are three amino acid that starts with the letter t if I ask you that which amino acid starts with the letter t you will say tryptophan cryptofan yes it is and the tyrosine these are the three amazing amino acid that starts with the letter t now if they ask that which are the essential amino acid and these are the option these are the options so you will use the mnemonic TV till 9 pmh if you see the mnemonic how many T&#39;s are there there is one t TV till so again one more T so there are two t but how many amino acid starts with the letter D crypto fan creonine and the tyrosine so this thyrosine starts with the letter t it is non-essential it is non-essential so we need to remember Z The Examiner knows that you are going to use the numer activity till 9 pmh so they will try to confuse you between tryptophan threonine and the tyrosine so we should know that tyrosine is a non-essential amino acid if you are using this mnemonic the thing that has to always keep always have to be kept in mind is that the tyrosine is non-essiation so I am writing this statement here is tyrosine is small essential if you remember these three things nine essential we have TV till 9 pmh tyrosine is non-efficient all the mcqs are going to be correct when it comes to the category of essential amino acid right if you want to write all the nine names all the nine names what are the TV till nine pmh what are the nine names are you can see in the list here these are the nine essential amino acid we have these are the in essential amino acid so you can see is the tryptophan valine threonine isolucine leucine lysine phenylene methionine and histidine tyrosine is non-essential thyrosine is nonstation right so uh in some books in some bugs you might find histidine is not written in essential in some books it might be written in semi essential category semi essential category so that is again we can say a controversial part I will tell you how to solve such McQ also right so the essential category the essential category initially we will we will have this concept that we will retain the histidine in the essential category only and the mnemonic is going to be TV till the npmh types acidine is a controversial part some book says it may consider a semi essential right when we see the negative nitrogen balance then we find that histidine is not the semi essential it is the essential amino acid but still in some books it is written as simulation so we will always have to keep that thought in our mind while solving the McQ so these are the essential amino acid that we have now coming to the semi-essential categories in the semi-essential category the only example that we have to remember in mind is Arginine the only example is arginine that we have to keep in mind the third category is non-essential the examples are remaining all the 12 amino acid remaining all 12 amino acid are going to be non-essential so we have the the essential semi essential non-essiation we have the essential semi essential non-essential there is a controversial part regarding the history in some books it is essential in some books it is semi essential so when you are solving the McQ and they are asking that which of the following is semi-ass changes let&#39;s say which of the following is semi-essential and in that quotient arginine is not given in the choice instead of arginine histidine is going in the choice then you will selected in a semi extension right so it all depends on the options that are given to you depending on that we have to find the best option so as I told you as example that if they say which of the following is semi essential arginine is not in the option then the second best answer is history right this is the the fourth classification that is based on the nutritional requirement the next thing is there are uh this is the this is the fourth category of classification that is completed then there is a special property of amino acid that some amino acid have a specific order or a specific smell right these are called as aromatic amino acid so this is a ectopic variety we can say is the aromatic amino acid means they have a peculiar order or a peculiar smell they are called as aromatic amino acid so what is important is to remember is the example what are the example of aromatic amino acid we have so to remember the aromatic amino acid I will just tell you a simple mnemonic how to remember the aromatic amino acid for example let&#39;s say right now we are having this class in a closed environment let&#39;s say all the closed all the doors all the windows are closed now what I do is uh I bring a rubber tire in this classroom and I burn the tire I burn the tire now what is going to happen is after some time everywhere there will be smoke of this burn Tire everywhere there will be smell of this burn time to get rid of the smell what you need to do is you need to turn on the fan so that the you will turn on the exhaust fence so that this smog will go out the smell will go out so the point is that wherever we have smell wherever we have smell what you have to do you have to turn on the fan wherever they smell you will have the fan wherever they smell you have the fat so the aromatic amino acid are those amino acid which contains fan in their name amino acid which contains fan in their name this is just a way to remember so the aromatic amino acid are those which contain fan in the name the examples are cryptofan the example is crypto fan you can see fan in the name one more example again phenyl Ln again fan in the knee so whenever is fan in the name it&#39;s aromatic what was the smell what you have burned what you have burned in the classroom that was tired so tylosine is also aromatic amino acid so tyrosine is aromatic amino acid apart from these the fourth one is history history that is also aromatic so the firstly you can easily Remember by the new money what is the smell this time tryptophanic the fourth one is histidine these are the aromatic amino acid we have so this is a ectopic variety of amination there is one more ectopic variety of amino acid and that is referred as derived aminas derived amino acid let&#39;s understand what is the meaning of derived amino acid so to understand that their definition of rewrite amino acid I will just use a simple concept that see the most of the amino acid most of the amino acid say for example methionine it is represented by a codon every amino acid will be represented by a codon the codon for methionine is Aug we&#39;ll discuss that in detail when we will discuss genetic code right but for now every amino acid is represented by a codon and for methion in the codon is aug but there are some amino acid which cannot be represented by a codon if amino acid cannot be represented by your codon that is called as derived amino acid that comes under the category of derived amino acid so what is deridamina said amino acid which cannot be represented which cannot be represented by codon that is referred as the derived amino acid usually the amino acid is the represented by a codon but if amino acid cannot be represented by codons called as desired amino acid so what is important is the example the example of derived amino acid the first example is hydroxy Proline hydroxy poly this is found in collagen found in collagen protein collagen is a protein the hydroxyproline is found in collagen then is the hydroxy lysine hydroxylizine that is also desired Amino Acid found in collagen then the next example is desmosine it is found in elastin then the fourth example is cystine this time the sustained molecule should not be confused with cysteine cysteine we have discussed earlier system we have discussed earlier what is cysteine is cysteine is a solve for cutting amino acid so what is cystine and what is system what is the difference between them so what I do is we know that cysteine is a sulfur containing amino acid what I do is I take two molecules of system let&#39;s say this is the first molecule and this is the second molecule of cysteine I take two molecules of the steam I joined these two cysteine molecule between by these two sulfur molecules so this is the bond that I am going to have is the di sulfide Bond disulfide Bond so if you take two system molecule joint via the disulfide bond this entire unit that you have got is going to be referred as cystine this entire unit that you got is referred as cystine right so what they ask is this stain is found where cystane is found in those molecule which contains disulfide Bond wherever we require disulfide Bond we will place cystine molecules because we know that cystine is having disulfide mode so the example where it is found is found in insulin insulin protein contains a disulfide bond so that we require system one more example that I can add is immunoglobulin that is antibodies that also requires cystine molecule insulin and immunoglobulin they require the cystine molecule the other examples of the derived amino acid so we have discussed four examples of delight amino acid hydroxyproline hydroxylizine desmosine and cystine few more examples that I can add is ornithin [Music] citrulline or anything these are the uh the other examples of the derived getting right so there are many others also but at least you should remember these six at least you should remember these six these are the six amino acid which are uh the derived amino acid so this is the complete classification of amino acid this is complete classification we have divided the amino acid base mainly in four subcategories based on our group then based on the the water solubility then we have discussed about the based on the their metabolismogenic then we have discussed about the nutritional requirement essential semi essential non-essential then there are two special properties one is the derived amino acid and the uh the aromatic amino acid one point I forgot to mention about the aromatic amino acid that you can write in the aromatic amino acid if I just scroll up the thing uh the nodes we have written that in the aromatic amino acid there are four examples tryptophan phenylalanine and tyrosine and distillate you can write there is one more point that you can write is aromatic amino acid has a tendency to absorb the UVS they have a tendency to absorb the UV rays when you place these amino acid in the sunlight sunlight contains UV rays so these amino acid will absorb the UVs among these four this uh among these four the tryptophan is having the maximum absorption of the UV rays so you can write this point here that all the aromatic amino acid have a tendency to absorb UV rays maximum UV absorption maximum UV absorption is seen with tryptophan this was asked in the exam earlier that which amino acid has the maximum tendency to absorb the UVS the answer is going to be tryptophan right so all the aromatic have a tendency to absorb the urase the maximum is with the the maximum is with the tryptophan maximum is with the tryptophan so this is the complete classification of the amino acid because as I saying that earlier we have only 20 types of amino acid now we have added the 21st and the 22nd amino acid so we should know few details regarding them one is the 21st amino acid the 21st Amina said the name of the 21st amino acid is selenocystein Salon 60 if they ask that what is the codon we do not have to remember all the codons we have to remember only three columns one I already told to you mithyanin that is the AUG the codon for Salon system is u g a if they ask that what is the the precursor precursor amino acid means cellular cysteine is synthesized from which amino acid what is the precursor the precursor is Siri saline will convert ultimately into cellular system so the precursor amino acid is Siri is Siri when it comes to the 22nd amino acid 22nd amino acid the example of 22nd amino acid is the name of the 22nd amino acid is pyrolysis pyrolysis the codon for pyrolysine is UAG there is no as such precursor for pyrolysis so these are the details to be remembered for 21st and 22nd Amino say 21st is 7 16 22nd is spiralizing 22nd is spiralizing so once we are uh completed once we have completed this entire classification centers is a very important topic there is going to be one question for 100 from one question from the this discussion of the classification of amino acid

Transcript for:Amino Acids: Structure, Definitions, and Classification

Transcript for:
Amino Acids: Structure, Definitions, and Classification