Science & Technology - Class 1 by Dr. Shivin Chaudhary | Complete Module for UPSC IAS Prelims 2024

hello and welcome to the first class of science and technology for upsc prelims 2023 I'm Dr Shivan Chri so this is the first class now let us start with biotechnology is the basic of life is the basic of life so all life is made up of cells the fundamental unit of life is B livan all living organisms are made up of okay and if there is one cell just one cell like this one single cell is capable of independent existence single cell it's possible okay so cell is the fundamental unit of life chemistry at andells can exist independently okay so this is what is meant by the statement cell is the basic unit of life now a cell has many components okay comp component the cell firstly has a nucleus at the center this red thing is the nucleus what is the nucleus nucleus is a brain of the cell bra that is the nucleus so the nucleus controls all the functions of the cell but let's start with nucleus being the brain of the cell and it controlling everything that the cellular functions have okay cell is type so there has to be a membrane that is the cell membrane the cell membrane is the boundary of the cell the nucleus is the brain of the cell now in this boundary cell membrane boundary there is a fluid Matrix fluid compon that fluid is called the cytoplasm MBR nucleus copas cell organ you must have read that mitochondria is the PowerHouse of the cell Powerhouse because mitochondria energy provide mitochondri designed mitochondri it is a cell organ organ means one component of the cell particular function particular function to provide energy to the cell then there is a cytoplasm cytoplasm is what a fluid Matrix in which all the components of the cell are fluid protein then there is a nucleus nucleus is brain of the cell and then there are some cell organelles which have particular functions one of those cell organal is the mitochondria this slide is complete okay cell all life is made up of cells body approximately there have to be two two trillion cells it humans May estimated 2 trillion so start all living beings start from a single cell they divide and they grow just number of cells right any growth that is happening from a small baby to a big human it is only through cell division number of cells have to divide and increase for the cell to grow correct has to reproduce for growth to happen figure but example and when he becomes a big man he has let's say 10,000 cells so these cells have to reproduce they have to create more cells like this right only then this growth can happen so this reproduction of cells is important cell will form two Cells Two cells will form four cells etc etc etc so this one cell it is capable of independent existence it has some information information like there has to be a mitochondria there has to be a cell membrane there has to be cytoplasm function [Music] control it has to make two other cells then what does it have to do it has to transmit the complete information to these cells information divide they also have to have the same information only then they can work it has to have all the components coplas they will also have to have a nule cytoplasma mitochondria and everything else right so there is some information this information has to be transmitted from one cell to the next to the next when the growth is happening right so growth can occur only when cells reproduce and important information to run the cell has to go from one cell to the next cell right your information will tell the cell how to run now this information will have to be stored somewhere right this information also has to be stored somewhere now this storage of information is happening in what we call the DNA DNA stands for deoxy ribo nucleic acid DNA deoxy ribo nucleic acid so this information of how the cell is supposed to run components this is in the DNA DNA de oxy ribonucleic acid because this is what a DNA looks like it has a double helix model meaning SAA this is one Helix this is the second Helix so this is the model of DNA every cell has this DNA which is this information which it can pass on to the next cell right okay this double helix structure of DNA is shown here but right you have to zoom in a lot to see a cell so if you zoom out of a string like this it will start looking like this zo it will look like this right Zoom DNA looks like this like a strand like this but actually a DNA has two strands double stranded DNA and the model is called double helix model because it looks like this okay now mopic the information is a lot so what needs to happenand Mo right so this huge strand that looks like this has to be condensed and kept inside a small cell so what is the solution the solution is you need to condense the DNA this is what it looks like if it is uncondensed but what can we do we can coil it like this so it will become condensed and then you put this condensed thing inside the cell every cell of our body has DNA and you have seen an example of this um but C and I know you are ashamed to admit this and I also ashamed to admit this but Professor what did that forensic pathologist in C do he used to take the hair of somebody from the crime scene a nail a skin cell of somebody and identify the person because every cell has DNA now we have started from one cell that cell had certain DNA certain information and that one cell has become into this man today so all the cells are derived from this one place so they have the same information the same DNA and every cell has this DNA it is a two stranded double helical molecule right and it has to be condensed and put inside the cell for that condensation and putting inside the cell to happen it has to be coiled this slide is complete what do we know so far and see these sort of slides I have put in every lecture so that class engagement or division what do we know so far a cell has to reproduce for reproduction and why does it have to reproduce for growth for reproduction information has to pass on to the daughter cells like I told you one cell to two cells so all the information has to pass on here right DNA deoxy ribonucleic acid is the information inside the cell every cell has DNA every cell of the body has CN DNA you can remember C here DNA is present in the nucleus this we have seen nucleus s like this this is where the DNA is and although this is not the exact explanation but you can understand that deoxy ribo nucleic acid right it is inside the nucleus so nucleus brain of the cell that contains the DNA deta don't worry about it DNA has to be condensed as it is very long string I have to coil it like this and DNA is a double helix molecule all of these things right all of these things we know so far okay DNA this is what DNA looks like double helix but DNA first coiling chromatin now this is a new term that you haven't heard before so take care chromatin okay and chromatin when it is further condensed further coiled make made igom short it is called chromosomes this term you must have heard before chros right but what are these chromosomes this we don't know chromosomes are nothing but condensed DNA why are we condensing the DNA DNA is very long we have to put it inside the cell where inside the cell in the nucleus why in the nucleus because nucleus is the brain of the cell so all the information for controlling the cell has to be put inside the nucleus right I hope it is making sense so far let's get back to our original idea of the cell this is where we started this is what a cell looks like right this is a cell membrane cell membrane it used to bind the cell boundary boundary was cell membrane now first question for you this is a fluid Matrix in the cell what is this fluid Matrix called This is question a then this is the PowerHouse of the cell this it is a cell organel called Powerhouse of the cell what is this called a here is the cytoplasm fluid Matrix B is the mitochondria Powerhouse of the cell now this is the nucleus this is where I said that the DNA is okay I just told you that the DNA is put inside the nucleus so nucleus Zoom let's look inside the nucleus what it looks like it looks like this nucleus also has a membrane as a membrane to bind it a membrane cell membrane this was the cell C membrane there is a nucleus it also has a MBR so what will that membrane be called it will be called the nuclear membrane now inside that nuclear membrane that is the main question components first component is chromatin chromatin we have just read chromatin it is the first coiling or condensation of DNA what is the second coiling chromosome the DNA is coiled it is called chromatin it is placed inside the nucleus other than the chromatin the nucleus also contains something called the nucleolus so DNA condensed coiled to form chromatin chromatin will have will be there inside the nucleus inside the nuclear membrane and the other thing that will be inside the nuclear membrane is nucleis good now we know DNA is the information and doubt are DNA information right now we're answering that question we know DNA is the information but why why is DNA the information because DNA through a process called transcription forms RNA and RNA through a process called translation forms protein information like this is too much new information don't worry this thing DNA to RNA to protein I will repeat at least 100 times in the next four classes at least 100 times you will see this in the next four classes so you will remember all of it don't worry DNA forms RNA RNA forms protein right explan why DNA is the information what I have done is a logical policy called Kicking the can down the road man DNA is the information because RNA and protein has to be formed from DNA next question is why RNA has to be formed why protein has to be formed this we will address now but terms first term that I have told you is transcription transcription is the term which defines what happens when DNA is converted to RNA then there is a term called translation translation is what happens when RNA is converted to protein all of that transcription and translation this is something you need to remember so how will you remember it somebody had asked me transtion and translation these are the two things now there is ction and translation C comes before l so the first conversion will be transcription translation L comes later L late the second thing will be translation right transcription is the first process translation is the second process hope you understand again now two important questions why are we forming RNA and why protein let's address that okay second question address why are we forming proteins okay then we'll talk about the first question cell information as the parent why are we forming protein chicken chickenin but that's not the protein I'm talking about I am talking about the protein that is inside the human body that is used to you know do functions in the human body protein prot related this this discussion also we'll do but why protein why as protein being formed protein enzymes so the enzymes in the body are the form of protein that we need let's say you eat table sugar which is sucrose sugar why does the body need sugar body glucose glucose extra this is what the body eats sugar for sugar carbohydrate carbohydrate provides us with energy so sugar using like it will be broken down into glucose and then glucose will be broken down to give some energy okay so there is an enzyme in the body called sucra don't need to remember just given as an example there is an exam enzyme in the body called sucra this sucra breaks down the sugar there are some more enzymes involved in a process called kreb cycle don't need to remember just given as an example that then turn the glucose into energy so table sugar or sucrose that we eat is first using the enzyme sucres converted into glucose then glucose is made into energy in our body but we need enzymes and these enzymes are the proteins or the information that is actually there DNA RNA protein these proteins are these enzymes protein enzyme every cell has to needs energy called mitochondria mitochondria in every mitochondria the glucose is being turned into energy this step right here glucose turning into energy is happening inside every cell in the mitochondria so in the mitochondria certain enzymes have to be there now how will the mitochondria know that I have to produce these enzymes only this information is coming from the DNA so when the first cell has certain information that information codes for these enzymes next cell b when the daughter cells have to be made the daughter cells also need the information of how to make this enzyme because if they don't have this enzyme they cannot use glucose they cannot use glucose they cannot get energy they cannot get energy they will die so enzymes are the proteins that is why this information of protein transmission has to be there every cell must be capable of making these enzymes so for a cell to reproduce a new cell has to form and new cell must have all essential enzymes when this reproduction was happening these new cells they also need to be able to exist independently for that they need these essential enzymes this is why protein is there so when I told you DNA to RNA to protein there were two questions why RNA why protein the first question of why protein protein you can also use the word enzyme the word the question of why protein has been addressed this is the model of DNA double helix model looks like this let's zoom in and see what is there inside the DNA okay now DNA has certain nitrogenous bases you don't need to go into the detail of this but you do need to know a little bit about this it has certain nitrogenous bases okay they are chemical mole ules so these are the chemicals that make up the DNA okay we are studying them I'm DNA was looking like this double helix strand we are looking zooming inside the DNA and seeing what it looks like so it has four chemicals edine thyine guanine cytosine four terms so this you'll have to remember nothing we can do here so adenine thyine guine cytosine a g c and T this is what they stand for the DNA you know what this information looks like so when you see a DNA molecule strand like if it is a two strand molecule it is like this but let's say I look at it like this just open it and see it like this it will look something like a a g c t any sequence can be there so this sequence is of a a g c t this sequence is what sequence of chemicals these sequence Adine thine guine cyto and if I open and look at the DNA I will see these molecules like this now there is a like there is a complementarity because those strand DNA it is like this a binds to T C binds to G so on the Strand and if on one side just one second let me clear this if on one side there is a g c and T So a you will always see t g you will always see C similar c g so these are the four chemicals of which DNA is made up of DNA sequence it will look like this a g c information we'll discuss that DNA has these molecules it is a double helix two strand molecule right now if I'm seeing a two strand like something it has two strands it is obviously difficult to process okay what am I talking about let's see this you we have already seen that it is very very super coiled so what we need is those information so this two strand into one strand is why we are making the RNA RNA is a single strand molecule out of these two strands the important information that codes for the protein is converted into one strand of RNA this then is made into protein or enzymes so we had two questions why RNA why protein the question of why RNA has also been addressed from a two strand we need one strand from one strand we have to form protein why protein or Y enzymes that has also been addressed okay let's compare DNA and RNA once DNA looks like a double helix like this it has four things adenine thyine guanine cytosine a GC four chemicals the process of converting DNA to RNA is the first one so c c it is called transcription okay then RNA is a single strand RNA is stands for ribonucleic acid deoxy acid ribonucleic acid so there is a difference in the structure differ deoxy grp don't need to know just need to know the full form that that was a double helix molecule this is a single strand this makes this single Str DNA forms RNA using process of transcription and RNA then forms those proteins or those enzymes that we have discussed with the process of translation the later process happens with L translation forming protein DNA had four chemicals a t g c how will you remember atgc a binds to T and G binds to C so so this you can remember by one of my favorite places in the world called at the Girls Club okay at the Girls Club a binds with t g binds with C just remember that in a DNA at the Girls Club a will bind to t g will bind with C at the Girls Club hope it's all clear GNA mole a t g c chemal B Adine thyine guine cyto double helix model single there is only one other small difference with RNA RNA thyine is not there in RNA there is something called U or urin stands for so in the DNA a was binding with t g was binding with c yeah a is binding with u g is binding with c and a is binding with u called Ur acid okay all right d we again two questions y DNA y RNA y protein DNA is the information RNA for processing proteins are enzymes now let us see that process again DNA looks like this double standard molecule just for ease of showing okay so I have just shown this I have just shown this in a simple manner so this is DNA D transcription DNA is making RNA transcription now what isna doing RNA is carrying the message of DNA DNA message easier processing so it is called mRNA or messenger RNA thing is process is called transcription this is mRNA messenger RNA right we just have to remember DNA forms mRNA messenger RNA using transcription RNA then forms proteins or enzymes using using the process translation okay what do we know so far cell has to reproduce for reproduction information has to pass to daughter cells why this information has to be there because daughter cells need that enzyme so that it can perform all the essential functions of life like producing energy cell has to reproduce for reproduction and growth information has to pass to daughter cell from one cell to the next cell information and enzymes have to pass DNA is this information every cell has DNA why how do we know every cell has DNA B PL Professor saluk used to identify the criminal so obviously every cell has DNA DNA froms forms RNA with the process of transcription first which RNA it will form mRNA why mRNA because it is carrying the message of DNA the beautiful message of DNA to make the protein is there in the MRNA messenger RNA using the process of transcription then mRNA will form protein or enzymes with the process of translation C comes first L comes later translation transcription and this is what central law of genetics in all living cells this Central law of genetics is obeyed it is also called the central dogma of genetics what is the central dogma of genetics DNA to R RNA RNA to protein DNA to RNA using the process transcription RNA to protein using the process translation I will repeat DNA to R to protein 100 times let's move on Central law of genetics what is the central law DNA to RNA RNA to protein correct DNA to RNA with the process transcription RNA to protein with the process translation but when there is a law there is an exception exception exception proves the rule and signs 14 right to equality ex while he is in office so there are certain exceptions to this law also this law applies only in living self DNA to RNA to protein Central law of genetics applies only in living cells DNA doubts how parents DNA is similar D don't worry I will address all of them DNA DNA double strand that is why it needs to bind okay RNA is a single strand so single strand doesn't need to bind anything else as a single strand it exists in the C Oran next time discuss right DNA is a double strand RNA is single strand DNA to RNA with the process of transcription RNA to protein with the process of translation now this is the law in living cells but there are some exceptions exception that exception is the virus viruses are exceptions to this rule of DNA to RNA to protein viruses are exceptions why are viruses exceptions let's discuss that life the basic unit is cell if you don't have S you are non- living correct what was the feature of Life reproduction reproduction for growth DNA RNA protein so only living cell can reproduce because you are living you will have cell cell will have DNA RNA protein you will form you will agree to the central law of genetics d DNA to RNA to protein only living cells can reproduce through DNA RNA protein correct s living cells reproduce because they are following the central law but there are there is a small exception which is viruses viruses they are borderline between living and non-living this is written in 8th Class ncrt 10th class ncrt 12th class ncrt that viruses are borderline between living and non- living why line viruses pass DNA RNA protein okay they have DNA RNA and some protein but they don't have their own cellular structure what was the cellular structure plasma membrane or cell membrane cytoplasm nucleus cell organel like mitochondria they don't have the cellular structure but they have DNA RNA proteins so what can virus do it can only reproduce when it has infected somebody virus is in the air if there is one virus it will remain one virus but if it infects me then that one virus of covid-19 one particle will become 10,000 particles because it cannot reproduce on its own but when it gets a living host it can get it can reproduce this is why a virus is a midpoint between living and non-living and this debate has not been settled yet living non- living Bing so virus is between living and non-living it can only reproduce inside the host cell not outside independently it has DNA RNA protein virus be DNA RNA protein but inside the host cell it can reproduce outside by itself it can't why this is what a cell looks like it's ribosome there is an organ prot it has the cell has all these things right energy we produce virus just has RNA and protein or DNA and protein nothing else difference structure that is what a cell looks like this is what a virus looks like influ able to see better it can't reproduce on its own okay so virus is therefore borderline between living and non-living what are the features of a virus it has DNA RNA and protein it can reproduce but only inside a host cell not by itself it has no cellular structure so how do they reproduce inside Ace we'll discuss that now but Soo if you don't have a car and you want to go somewhere what will you do you will sit inside the friend's car who is going there you have made no effort you have just sat inside a friend's car which is already going from point A to point B friend Delhi to jur you just sat inside the car so without making any effort this is exactly what a virus is doing I'll show you how virus process constantly DNA to RNA to protein constantly this process is happening reproduce it uses the DNA RNA genetic material this DNA and RNA is called genetic material genetic material of the host cell or the cell which it infects a living cellus worry today I will also show you a video of HIV infecting a cell hius that video I will also show you we'll look at this in a lot of detail host virus what is the host of the virus it is the cell that the virus is infecting virus it used our Machinery to reproduce then when it reproduce too much we get we like die or we have bad Health we'll see that also so when the virus multiplies too much the host will die like covid-19 killing its patient let's see this is how a virus life cycle looks like protein is constantly doing this process RNA protein so originally this DNA to RNA to protein is constantly happening correct when you get infected the viral DNA is getting integrated into your DNA let's see how that happens yeah virus life cycle virus prot or DNA capsid the term is written here capsid capsid virus and the nuclear genetic material which is DNA or RNA whichever whatever the virus has DNA will come integrate with the DNA of host host cellus virus when viral RNA is here viral protein is here they will integrate virus enter into your normal process of DNA protein multiply using your Machinery it multiplied and form many many cells then will burst it will a different now when all these viruses are there inside the cell it will enter it will burst the cell open and the cell will die cell membrane cell and the virus now goes on to infect a new cell virus it form 20 viruses now 20 viruses will infect 20 cells 20 cells will die 20 will become 500 500 will now go and infect 500 cells toid 19 we were dying yeah because it was coming into our body killing our cells and using our reproductive Machinery our Machinery of DNA to RNA to protein to multiply itself okay original process original process is DNA to RNA to protein your cell is doing this transcription translation viruses DNA some viruses have DNA they will what they will do is they have certain enzymes en they will integrate their own DNA into your DNA let me just show you differently DNA it will use certain enzymes in your DNA it will fit like this I'm not able to make the exact diagram but virus virus particle you are your cell is doing this process 500 times a day to 500 viral proteins now 500 virus particles are made now 500 virus particles inside a small which is not normal so what will happen virus this is how the virus life cycle works this is basically what is happening here the virus is entering the cell becoming a part of your normal DNA to RNA to protein infecting forming new viruses moving forward okay up which viruses like I said viruses they have their own DNA okay but some viruses have only RNA but what if a cell starts with the RNA it does not have DNA sorry it does not have DNA it only has RNA then what do we do if a virus has [Music] only what it actually does is integrates into your DNA not directly into your RNA okay so what was the original process the original process in your cell was DNA to RNA DNA to and what did we call this transcription virus virus starts with RNA makes DNA okay RN protein that is why viruses are exception to the central law of genetics they are not doing transcription they are doing reverse transcription virus is not doing RNA virus is not making from DNA to RNA it is not doing this it is doing this RNA to D if this DNA to RNA is called transcription what will RNA to DNA be called reverse transcription so the virus is doing reverse of transcription not all viruses do this multiply but some that have RNA are forming DNA first then integrating into your DNA then forming this process of DNA RNA protein to reverse process reverse of this so they are called retroviruses retro Ulta retro virus or using the process of reverse transcription is example HIV AIDS this HIV AIDS virus is a retrovirus because it starts with RNA from RNA it forms DNA then it integrates into your cell forms DNA to RNA to protein then makes new copies so HIV is retro virus virus is starting with RNA it can just normally integrate into your RNA let's understand virus this andin now what you will do you will make DNA to RNA to protein in your normal process and the virus will integrate its DNA here reverse transcript test you will form viral RNA you will form viral protein they what did the virus actually start from the original virus was also RNA plus protein and in this case you have formed RNA and protein for it if it integrates only here it will only be able to form protein not RNA but if it integrates here it will be able to form both RNA and protein it started as RNA plus protein and now with your cellular Machinery it has made RNA plus protein reverse you have made many viral many viral proteins now viral proteins and viral rnas will integrate virus and many many many more are formed it will break your cell your cell will die it will go on to infect a new cell this is how reverse transcriptase retrovirus is working DNA transcription to RNA RNA translation into protein this is normal central dogma of genetics a retro virus reverse of original virus virus AIDS virus starting R DNA it goes on to integrate with the host DNA to RNA RNA to protein you made RNA also you made protein also for the virus new virus cells are formed and it will go on and infect new cells and your original cell will die this is how AIDS is killing us virus can only do this inside host so I can only do this inside a living cell because virus is borderline between living and non- living so virus needs a living cell to reproduce video Let's see a video of how an HIV cell infects a normal C let's just see this video targeting HIV repli ation the replication of HIV 1 is a multi-stage process each step is crucial to successful replication and is therefore a potential Target of anti-retroviral drugs Step One is the infection of a suitable host cell such as a CD4 positive T lymphocyte entry of HIV into the cell requires the presence of certain receptors on the cell surface CD4 receptors and Co receptors such as ccr5 or cxcr4 these receptors interact with protein complexes which are embedded in the viral envelope these complexes are composed of two glycoproteins an extracellular gp220 and a transmembrane gp41 when HIV approaches a Target cell gp220 b to the CD4 receptors this process is termed attachment it promotes further binding to a co-receptor co-receptor binding results in a confirmational change in GP 120 this allows gp41 to unfold and insert its hydrophobic Terminus into the cell membrane gp41 then folds back on itself this draws the virus towards the cell and facilitates the fusion of their membranes the viral nucleocapsid enters the host cell and breaks open releasing two viral RNA strands and three essential replication enzymes integr proteas and reverse transcriptase reverse transcriptase Begins the reverse first transcription of viral RNA it has two catalytic domains the ribonuclease H active site and the polymerase active site here singl stranded viral RNA is transcribed into an RNA DNA double helix ribonuclease H breaks down the RNA the polymerase then completes the remaining DNA strand to form a DNA double helix okay so now what has happened here viral cc4 cxcr4 cc5 gp10 gp41 had entered the cell from singleand double strand DNA DNA reverse transcrip because reverse of the transcription process right now integr go interaction it Cleaves a dinucleotide from each three prime end of the DNA creating two sticky ends integr then transfers the DNA into the cell nucleus and facilitates its integration into the host cell genome the host cell genome now contains the genetic information of HIV activation of the cell induces transcription of proviral DNA into messenger RNA okay cell integrate what did the person just say he said when the DNA of the virus is integrated into the host cell then it forms viral messenger RNA through the process of transcription I'll just this is exactly what he's saying and this is exactly what we have studied transcription messenger the virus DNA is forming this messenger RNA activation of the cell induces transcription of proviral DNA into messenger RNA the viral messenger RNA migrates into the cytoplasm where building blocks for a new virus are synthesized some of them have to be processed by the virus protease protease Cleaves longer proteins into smaller core proteins this step is crucial to create an infectious virus two viral RNA strands and the replication enzymes then come together and core proteins assemble around them forming the capsid this immature viral particle leaves the cell acquiring a new envelope of host and viral proteins the viral proteins were formed viral RNA was formed viral RNA and proteins then again came together using the proteas and integr enzyme and now many virus particles are there it has killed this cell it is now going to move out and infect new cells this is how virus or HIV specifically is infecting humans the virus matures and becomes ready to infect other cells HIV replicates billions of times per day destroying the host's immune cells and eventually causing disease progression drugs which interfere with the key steps of viral replication can stop this fatal process okay so now I think the process is clear many times this replication will happen uh the host cell will be killed and new host cells will be infected virus infect it is infecting T cells cells are responsible for our immunity okay so this video was basically about that okay so this video was basically about it goes on to infect new cells it has first used the enzyme reverse transcriptase made its RNA into DNA then integrated with host DNA once it has integrated with host DNA what it has done it has used host process of DNA to RNA to protein to form its own RNA its own protein now what it has done up RNA ore let's see that INF CD that these tea cells are responsible for immunity and that is why HIV AIDS human immuno deficiency virus IM I will have immune deficiency that is why it is human immuno deficiency virus infecting CD4 plus TM CC CX using this receptor it had entered the cell it had three enzymes reverse transcriptase integr nucleus performing its protein in the end third person in the world has been cured of hi I'm just telling you that something like this has happened it's in the news we'll study this also so I hope you understand this process we have read DNA to RNA to protein transcription translation virus reverse rro virus retro hivs virus retro virus right it is using reverse transcriptors to integrate Ulta RNA to protein and you also have to remember it can only do this inside a host it cannot do it independently correct all right then video say was little bit too complex and fine let's let's replay what had happened in that video reverse virus I'll use a new slide DNA is inside the nucleus in the form of [Music] chroma nule inside this you know T cell what did it do this T Cell went inside here it had to go sorry I'm am so sorry this virus this HIV virus RNA it wanted its own RNA to integrate into the T cell's DNA [Music] T Cell was forming DNA to RNA to protein every day every day it was doing this process many many times so the virus integrated here and formed d DNA to RNA RNA to protein HIV had started with RNA and certain proteins which were enzymes DNA using this Machinery many viral RNA were formed many viral protein were formed cell does not have enough ability to hold that pressure the cell burst the cell died C membrane you know when this was a cell PR the membrane burst open membrane burst open and this HIV particles now went on and they infected a new right we'll discuss that when we do vaccines okay T Cell there was nucleus nucleus nucle or chromatin chromatin will be the DNA of the T Cell okay virus will come HIV virus hi hi enm DNA en reverse transcript correct okay normally DNA to RNA to protein first enzyme reverse transcript to form DNA second enzyme integrates to integrate with t cell's DNA now DNA to RNA to protein is also happening normally was normal what it did normal process now this meant many many HIV particles are now formed which burst open the pressure and the T Cell died you don't need to remember the names of receptors you also don't need to remember the names of enzymes that HIV have except for the enzyme reverse transcripts because it is called a retrovirus okay so DNA to RNA to prot right so I hope this part is clear questions right the idea is question start I will give you one minute for the question timer you write your answer in then I'll show you the answer and discuss the solution questions they will all be previous year questions okay so now we're starting with the first question 2016 question solve this tough question I have not taught you this exact term but use your brain e [Music] okay question in context of developments of bioinformatics the term transcriptome sometimes seen in the news refers to what trans cryption right where did we read this term yeah we read it when DNA was making RNA and which RNA messenger RNA okay so transcription will be the full range of mRNA molecules expressed by an organism B how is this genetic mutation M like you can make this assumption yeah like this much you will have to do right because see it was very easy for me I could have easily said and then giv you the question and then show you the questions questions right but good most people have given the right answer and if you have given it wrong it's fine the description of a mechanism of gene expression gen we have not even discussed the term Gene but that's okay I hope you now understand transcription it was DNA to RNA con RNA messenger RNA which means it carries the message of DNA so transcriptome is the full range of mRNA molecules expressed by an organism okay answer is B let's move on to the next question which of the following statements are correct viruses can infect 1 123 and select the correct answer again you have 1 minute e [Music] okay viruses can infect what virus can infect living cell virus living virus can infect bacteria fungi plant bacteria be living fungi be living plant be living so virus can infect any of these answer is D can infect we'll discuss that when we are doing health issues PL virus disc just giving you an idea of previous year questions since can that should also have been a hint but by vus can infect any of these because all these are living right so virus can infect bacteria fungal plants because virus can infect any living cell different virus different host now covid-19 will not infect plants and a bacteria phase will not infect humans but viruses have the potential so can will be all of the above answer is D okay now read this question which of the above can be cultured in an artificial or synthetic medium 2021 question you have 1 minute e [Music] virus or living replicate right it cannot replicate by itself or in an artificial medium it needs a living medium so in a synthetic artificial medium which of the above can be cultured to so obviously virus cannot be cultured in artificial or synthetic medium why because synthetic medium living is atic infection it is a infection that actually happens in pangolins and bats and it has come to humans to what Pangolin say in like it is alleged in the Pangolin they were doing some experiments after infecting it with this virus and it got leaked it got transmitted to a human and then to others right it is not on a lab manufacture 19 wherever you will read Corona virus you will hear a term called lab leak Theory not lab manufacturer Theory Indian Express May lab leak Theory not lab manufactur Theory laim you can infect some living thing do experiments and it can leak by coming into a human if you don't take proper precautions but you can't make it synthetically in a lab right so it is a lab leak Theory it virus cannot be cultured in a synthetic medium eliminate third option answer here is a right okay answer is a all right let's do this question now you have 1 minute e [Music] good we are doing the toughest level of question possible so firstly thanks a lot for participating right these are direct upsc questions and things some things that I haven't taught you yet so if you're are participating it's great okay great job thumbs up to all of you okay now virus can be cultured in any synthe medium so B and are now this question after the previous one virus energy generate where are the enzymes for generation of energy they are in the mitochondria in a cell and they don't have this enzyme they don't have cellular structure virus are transmitted from one organism to another by biological vectors only confusion virus replication replication your reproduction your culture what does this term mean this means that one virus a virus one particle is forming many virus particles transmission transmission transmission means that virus is going from one person to the next person one virus particle is going from this one person to the this person this is transmission of virus that is replication of virus okay first process is this this is virus particle if it does this then it is what replication this is virus particle if it goes from here to here this is transmission of virus okay now this process of viral replication can only happen inside living because it will need it will need the host DNA to RNA to protein Machinery to do this understood it can only happen in living second thing is this transmission from one person to other reproduction just one viral particle is getting transmitted to you biolog Vector any Vector can take it it can go right question this is culture this is transmission replication or culture and transmission let's go back to the question viruses are transmitted from one organism to another by biological vectors only meaning what okay organism say say it can go through the air also it cannot reproduce in the air but it can go in the air right may like when I'm sneezing how is covid-19 coming to my like body so what is happening is LS lungs cells cells 19 infected when those when 19 is multiplying those cells now when I'm sneezing those things are getting emitted out right emiss drop partic the third statement is wrong answer here is a one only because transmission is different and replication is different again this was a tough question it's I had just P this to explain the difference between the words transmission and culture okay moving on e okay they adenovirus has single strand DNA genomes I don't know let's leave that retrovirus have double standard DNA genomes what is retrovirus Ulta it will have what genome RNA genome correct statement cannot be first option cannot be third option common cold is sometimes caused by Ado virus again it was very easy for me to teach you what Ado virus is and then give you this question obviously I canot teach you every virus in the world but you have to understand this some caused by an Adeno virus common cold very possible AIDS is caused by a retrovirus answer is B second statement is correct and sometimes they have made it very generalized so chances of it being correct increase and second part AIDS is called by retrus and Ado virus is a family of viruses this influenza is also one and we discuss adino viruses when it comes to it but first statement realize first statement G was important here and that is why the whole Char of understanding retrovirus is important less previous questions asked question about virus synthe virus be cultivated in synthetic medium virus lack the enzymes for generation of energy virus can be transmitted with biological vectors virus virus topic important in the upcoming biotechnology lectures one of will be dedicated virus stud biological Vector house fly biological Vector means living the particles of your sneeze are not living right biological things have to be living right and virus can also go through other things it can go through air also air is just normal it's not it's not biological air is a chemical quantity transus right we will not even leave a single previous year question from 2013 to 2022 2013 identify because that is when the format changed so the questions format has also changed from 2013 okay the one pager of this class up is please download let's revise all of that start with the idea that cell is the basic unit of life cell has nucleus cytoplasm cell organal for growth and reproduction important information needs to be transmitted information is deoxyribo nucleic acid DNA is a long molecule needs to be condensed for condensing what does it need coiling DNA right DNA forms chromatin chromatin to chromosomes in the process of coil this is the first part of the one right good second Central law central dogma of genetics there is transcription for DNA to RNA previous question called transcript then there is translation for RNA to protein okay so DNA to RNA to prot transcription DNA to Mna messenger RNA translation mRNA to protein TR RNA and R RNA help in this process RNA Q why RNA was the first question because it is a single Strand and processing is easier why protein was the second question because we need enzymes enzymes to do our function okay RNA versus DNA difference RNA versus DNA RNA is single Strand and RNA has urin in place of thyine this is the second part of the one pager DNA to RNA to protein the central dogma of genetics okay now virus virus is borderline between living and non-living this we saw why is it borderline because it cannot reproduce on its own it needs a host Machinery to reproduce virus has DNA RNA and protein but no cellular Machinery ma it has DNA RNA protein so it needs the host cellular Machinery can reproduce only inside host cell by integrating into its genetic material that means it cannot be cultured outside the human body in a simp synthetic medium okay some viruses start with RNA so they are retroviruses they in the process of DNA to RNA to protein in the process of DNA to RNA to protein these viruses are starting at this process so they have to first go here using the enzyme reverse transcriptase form DNA then do this so they are called retroviruses and they use the enzyme reverse transcriptase reverse transcription is done by retrovirus so this is the third part of the one Pages which is virus this is what we have read today then we read did some previous year questions can virus be cultured in artificial medium answer is no what genome does retrovirus have what genome does retrovirus have DNA or RNA genome we'll read in the third class what genome and genes are but what genetic material does it have what genetic material does it have it has RNA what is a transcriptome transcriptome is the full complement of mRNA it is formed after transcription it is the messenger RNA question DNA barcoding but that question since it was done in the demo class also but we'll do it next time that particular question we'll address next time it's there in the one pager but next time I thank you all for joining I hope you understood you can leave a small review in the comments you know what you are getting to if you want me to go slower or faster or if there's any language issue you can leave that you can leave here in the comments so that's it thank you for joining see you tomorrow

Channel: Sarrthi IAS

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Id: a2ZYiy0Oess

Length: 88min 13sec (5293 seconds)

Published: Mon May 06 2024