now we start the 18th chapter and this is 5090 O level syllabus but this works for IGCSE and GCSE as well this is the syllabus 2023 and we're going to do biotechnology and genetic modification which is a slightly change in the in the new syllabus so let's talk about this now now as we go through the syllabus biotechnology and genetic modification the first 18.1 is what biotechnology and 18.2 is about genetic modification now in biotechnology we have to explain the role of the yeast in the production of bread and ethanol then understand that bacteria so we need to know the structure of bacteria and why is it used in biotechnology and genetic modification why because the number one the only thing is they have a very rapid reproduction rate they multiply every 20 minutes and their ability to make complex molecules so that's why we put the gene for insulin into bacteria because they're able to make that insulin molecule describe discuss why bacteria are useful in biotechnology and genetic modification limited to number one they know ethical concerns so everybody is okay there's no religious issues there's no ethical issues that okay we shouldn't use bacterial just like there's animal rights and all that so they know ethical concerns over the manipulation and growth of bacteria so we can do anything we can manipulate them we can grow them easily not a very nice thing but we can and then of course the presence of plasmids so what are plasmids we'll talk about that then we talk about how do we culture bacteria so we use fermenters and these are used for the large scale production of useful products by bacteria and fungi including the conditions that need to be controlled limited to temperature pH oxygen nutrient Supply and waste products so we'll talk about the fermenters these huge tanks where we grow these bacteria and we can grow bacteria and we can grow fungi like we grow the fungus penicillium and it produces the antibiotic penicillin for us then number five is describe the uses of enzymes in biological washing powders why we use enzymes in biological washing powders is to remove the stains protein stains you spilled egg on your shirt now why would we have a washing powder because egg is albumin protein so in order to wash off that stain we use biological washing powders then pattern is for fruit juice production we want clear food we don't want the particles of the legnin and pectin in it so we don't want any of that so we want a clear so we use pectinase and then we use lactase for lactose-free milk but some people are allergic to lactose and they get bloating and they get uh you know problems they get pain in their abdomen so we have to get lactose free milk because lactose is a sugar which is found in milk so all these are now in the 18.1 in which we're going to be discussing biotechnology now coming to the first point the role of yeast in baking bread and ethanol and so the first important method the traditional method in making bread was what you added warm water sugar and yeast to a bowl and you allow it to sit till it's become a public called proofing the yeast you're just proving it's going to work then you add flour to the mixture to make make a soft dough so you've added the flour and the water and the sugar and the yeast and now you're making a dough out of it now need in the flower need means you sort of press into the flour and smooth and become smooth and elastic allow to rise fermentation until it is doubled in size so if you have that in a beaker this was the dough the dough is going to rise double its size then you punch down divide and shape and allow to rise again again and then you bake so this was the traditional method of making bread now when you look at it what is fermentation fermentation also known as alcohol fermentation is the breakdown of sugars by bacteria and yeasts using a method of respiration without the need for oxygen these bacteria and these are microorganism and what do they use they use glucose fructose and sucrose are converted into energy for these cells the products of this process are ethanol and carbon dioxide as metabolic waste products when the solution reaches about 15 ethanol then the enzymes can't function and the process of fermentation ends why because ethanol is toxic it is going to kill the yeast and the bacteria if any present now looking at the equation for fermentation is very basic you see you've got to understand that glucose is respired anaerobically that's why it's called fermentation it's another name for anaerobic respiration we're going to produce ethanol and carbon dioxide now in bread we need the carbon dioxide to make it rise in the production of ethanol with just the ethanol that we need so ethanol and carbon dioxide are two main products and we are using the microorganism is yeast fermentation is used for bread making and the production of wine it is also used to make products such as cheese yogurt and soya sauce the word equation is glucose ethanol and the symbol equation is this so C6H12O6 gives you two c2h5oh plus two CO2 now the second point of the syllabus is why bacteria used in biotechnology and genetic modification see the two separate things biotechnology is this bread and mines and improving but genetic modification is when you change the genetic makeup of an organism somehow we won't talk about it how like we take the gene for insulin from a human being and put it in the plasmid and then put the plasmid back into bacteria now we've got genetically engineered genetically modified bacteria and these will produce insulin for us but in biotechnology we just want to use like bread making is biotechnology but genetically modifying bacteria producing insulin is genetic modification okay now why do we use bacteria the first question is that number one they have a rapid reproduction rate number two they can make complex molecules for us like they can make insulin for us we need insulin because people who are suffering from diabetes need the insulin but we can actually put the recipe for making insulin into a bacteria and the bacteria will make insulin for us so they can make complex molecules now there's no ethical concerns no ethical concerns about manipulation of growth you see as I will talk to you later when we used other animal products then we had problems they were religious ethical issues there were other issues that you know people would people who are vegetarians would not take any animal products and the fourth now these are four points which Everybody Must remember rapid reproduction rate number two makes complex molecules number three no ethical concerns bacteria is not Haram or Halal or it is not banned in certain religions or it is allowed in certain religions or certain people say okay well we can't have bacteria because you take yogurt yogurt has bacteria in it then the fourth and the most important point is that the presence of these circular little uh little Circles of DNA which are called plasmids oh these are the ones which are very important which we can actually modify and then put them back into the bacteria so these are the three these are the four important things rapid reproduction rate make complex molecules no ethical concerns and presence of plasmids now let's discuss the first point rapid reproduction rate now how do bacteria divide they divide by binary fission please remember this is not mitosis this is not mitosis everybody should be very clear this is not mitosis binary efficient is a totally different matter in mitosis there are certain stages of mitosis like prophase metaphase anaphase integral of phase well we don't discuss that in all levels but everybody do we do talk about it just a little bit now this is binary efficient now what happens in binary fission cell replicates is DNA first the DNA this was the original DNA now a copy of that DNA has been made so cell replicates its DNA there is a cell wall in bacteria there's a cytoplasmic membrane there's a replicated DNA now number two the cytoplasmic membrane elongates separating the DNA molecule so now the cell has become a little longer then the cross walls form membranes imaginates cross wall formed completely and two daughter cells formed now this happens every 20 minutes so now imagine that there's a place so there's some Beaker in which we have one million bacteria in 20 minutes and 2 million and then the two million are four million so with every 20 minutes they are going to become double so 1 million two million two to four four to eight so you realize that this is enormous this is a very very rapid reproduction rate so when you genetically modify bacteria you can just grow them in ferment us and provide them the nutrients and they go to multiply every 20 minutes the second point was is why do we use bacteria is that they make complex molecules whether we use bacteria and biotechnology or genetic modification the reason is that they can make they make complex molecules they can make complex molecules now for instance I said let's take the gene for insulin and put it in bacteria and the bacteria can make insulin now what you have to realize is that insulin is a hormones a protein so for protein synthesis you need only two things number one you need the DNA now how are we going to so now we've got to understand in bacteria there's two types of DNA one is this nucleoid DNA which is this one all this right and besides these are little Circles of DNA which are called plasmids this is a plasmid right so what we do is we take out this plasmid and we change it how do we change it we cut it and then we add another enzyme another portion of DNA from a human cell or from any other organism whichever we want and then we put this back into the bacteria so now we've got this DNA which is now alien DNA and then what is going to happen is this DNA is going to result on the ribosome because please remember that all bacteria have ribosomes on the ribosomes the protein is going to be the protein molecule is going to be made because DNA is the recipe to make that protein say this DNA is for insulin now then the amino acids are going to be used and on the ribosomes the insulin will be made why why the ribosome ribosomes is a site of protein synthesis well what is done is that the amino acids are assembled together to make a protein molecule so what you have to understand is that they can make complex molecules so that ability is being then we are exploiting that we are in fact manipulating the bacteria so that it can now do things for us which we wanted to do uh the next part is that biotechnology and genetic modification why do we use bacteria is because there's no ethical concerns now for that I have to go back and tell you about how we used to use we used to get insulin from the pancreas taken from animals and then the insulin was extracted but there were religious concerns because sometimes we use cow's pancreas sometimes we use pigs pancreas now religiously some people are not okay with cows and some people are not okay with big pancreas so with bacteria they know such issues and then of course as I told you some people are vegetarians they do you not use any animal products so they would not have used this insulin either so this insulin which was extracted from animals had a lot of issues we'd had to slaughter a lot of animals to get their pancreas so a lot of animals were you know unnecessarily killed because we wanted their pancreas then as I said religious issues and as I said some people vegetarian so they would have issues but in bacteria there were no such ethical concerns now another very important point was that bacteria have plasmids so we say presence of plasmids you see other organisms do not have plasmids the human cell does not have plasmids so bacteria and plasmids now what are plasma the little Circles of DNA as I can show you here so what we do is we take out this plasmid as I've shown you by this Arrow we've taken off this plasmid which was inside this one here you've taken it out and now what have we done first we cut it so this plasmid was like this and then we cut it and then we add now this is a human chromosome which I have just drawn here so this was the human chromosome and now I have removed this part and so this part now is this is the part here which was removed now this part I put here and then I've used an enzyme to join it now this is called the recombinant DNA recombinant DNA is a new combination of DNA because some of it is bacterial DNA and some of it is human DNA and now this recombinant DNA we are putting back into a new bacteria we got it out of this one now we're putting out in a new bacteria and now this bacteria we go into culture in a fermenter and then this bacteria is going to produce insulin for us because we put in a gene for insulin taken out of a human chromosome into a plasmid and then we have put this recombinant DNA back into the battery into a new bacteria not from this one this one we have destroyed because when we actually destroy it we actually break the cell wall and the cell membrane to extract these plasmids and then we put it so the presence of plasmids is a very good tool for us it's for genetic Engineers plasmid is a very good tool to take it out then genetically modify it and then put it into another set of bacteria and then culture those bacteria and those bacteria will produce that protein for us for which we have put the gene now we want to discuss what is a fermenter now a fermenter is basically a big tank which is used to culture bacteria or microorganism even bacteria even fungi now what does it basically have let's look at the first one cooling jacket why do we need a cooling jacket if there are lots of people in one room it comes very hot becomes very stuffy because all everybody's at 37 degrees Celsius so similarly in the ferment we have millions and millions of bacteria they are all respiring and energy is being released I said energy is being released not energy is being produced energy is being released so it becomes hot so you need a cooling jacket to keep the temperature down now this is an impeller I'm just going to give you the definitions later on then there's a temperature probe then there's a pH probe then this is the culture medium which is the nutrient solution which we have put in for them to actually multiply then this is a top plate then this is a stirrer then this is an acid base pH sensor an anti-form inoculation pipe baffle oxygen sensor sampling point and compressed air Inlet and then sterile Air Line right now if you look at the another explanation of all this what is the first one the impeller it's an agitator to stir the medium continuously hands prevent cells from settling down and distribute oxygen throughout the medium impeller speed decreases at the size of the fermented increases sponger or an aerator introduces sterile oxygen to the media in case of aerobic fermentation process baffles disrupt Vortex and provide better mixing Inlet air filter filter air before it enters the fermenters because in the air they might be other bacteria or fungals fungals Force we don't want those to grow we only want a certain specific type of bacteria which we have put into the fermenter to grow then a rotor meter measures flow rate of air or liquid then a pressure gauge measures pressure inside the fermenter then there's a temperature probe measure and monitor change in temperature of the medium during the process then there is a cooling jacket to maintain the temperature of the medium throughout the process then the pH prose measures and monitors pH of the medium then there's a dissolved oxygen probe measures dissolved oxygen in the fermenter then this is the level probe measures the level of the medium then there is a foam probe detects the presence of the form then a sampling point to obtain samples during the process to check whether there is any contamination or not or should we just stop it then we have to clean up the whole fermenter and then start it all again then their valves which regulate and control the flow of liquids and gases another very simple basic design I like this diagram very much it's a product Outlet stirring patternless exhaust Outlet aerator motor acid base Inlet nutrient Inlet in a sensor probe for ph02 oxygen heat Etc and a water jacket and the next thing we want to discuss is biological washing powders now the normal washing powders which we have are not written you have to really see it whether you want to buy a biological washing powder or another non-biological washing powder now the majority of commercial enzyme production involves protein digesting enzymes proteases and fat digesting enzyme life Pages for use in the food and textile industry when combined in washing powders they are effective in removing stains in close now for instance you're eating your omelette and you drop some egg on your clothes well that is going to cause as a protein or you know like in operation theaters when we remove the the operation is done all that which was used the cows or the doctors and the and the other things that were used on the patient they have nothing but blood stains on them and blood is all mostly protein plasma proteins and proteins of cells so in order to remove these stains of protein blood gravy fats like you know grease you dropped oil on it or you'll not drop some butter on your clothes so these protein and fat molecules tend to be large and insoluble but when they've been digested the products are small soluble molecules which can pass out of the cloth so biological washing powder save energy because they can be used to wash clothes at lower temperatures and there's no need to use boiling water which will wash off the stains however if they are put in water at high temperature the enzymes becomes denatured and they lose their effectiveness so biological washing powders need to be used in warm water not hot water because the hot water is going to denature the enzymes that I basically be using the enzyme to wash off the stains but if we're going to use hot water well the enzyme will be denatured and it won't really work now the next topic is investigating the use of pectinase pectinase is an enzyme which actually dissolves the solid particles in the fruit so when you crush the fruit or you're drinking out the fruit juice what you do is if you add this pectinase then more of the juice is extracted so it says investigating the use of pectiners in fruit juice production now make 100 centimeter cube of Apple puree using a liquidizer or use a tin of Apple puree Apple Beauty you understand it just take the apple and just crush it put it without any water or anything put it in the blender and you know just get the puree out of it transfer the puree to a 250 centimeter Beaker add one level teaspoon of powdered pectinase enzyme and stir the mixture and leave it for about 5 minutes place the funnel in the top of 100 centimeter measuring cylinder and line the funnel with the folded fit fit the paper transfer the puree into the filter paper so you've got the funnel right and you've got the filter paper so place a funnel in the top of a measuring cylinder and line the funnel with the folded filter paper now you transfer the puree the puree is transferred here into the filter funnel and leave it in a warm place for about 24 hours but you had added pectin is to it remember that that you transfer this 100 centimeter Apple puree then you added one centimeter one level teaspoon of powdered pectin is then you placed it then you transfer the puree and leave it in a warm place for about 24 hours other measuring centers could be set up in a Safeway with purely left to stand at different temperatures to compare the success of juice extraction now we're going to be really looking up is okay how much do juice did we get out of this apple puree did we get 50 cm Cube 60 cm Cube 80 cmq because what is it going to do it is going to crush the cell walls and the cell membranes and everything the pectin is going to remove all that so that the juice from inside can all come out so it is the use of pectinase in fruit juice production please understand that you will also use pectinase in clarifying when we get very clear juices when we want to have clear juices even then we want to remove the solid particles in it so we also use that in that process but here it is not about that it is about the fruit juice production now the last topic that we are going to do is lactose-free milk now why do we need lactose-free milk because people some people suffer from lactose and tolerance which is a digestive problem where the body does not produce enough of the enzyme lactase as a result the lactose remain in the gut where it is fermented by bacteria causing symptoms which is flatulence wind diarrhea stomach pains many foods contain contain dairy products so people with lactose intolers cannot eat them or suffer the symptoms described above however lactose-free milk is not produced using the enzyme lactase a simple way to make lactose-free milk is to add lactase to milk the enzyme breaks down lactose sugar into two monosaccharide sugars glucose and galactose both can be absorbed by the intestine an alternative large scale method is to immobilize lactose on the lactase on the surface of beads the milk is then passed over the beets and the lactose sugar is effectively removed this method avoids having the enzyme molecule in the middle because they remain on the beads the food industry uses lactase in the production of milk products such as yogurt it speeds up the process and makes the yogurt taste sweeter because you see the the lactose is less sweet so when it's broken up into glucose and galactose then it makes it more sweet there'll be more glucose more sweet naturally because glucose is very very sweet so lactose free milk is produced for people who have lactose intolerance this is people who suffer from lactose and tolerance so they cannot have any dairy products they cannot have any Cakes and Pastries which have cream on it and they will have problems so we can produce lactose free milk in this manner this completes 18.1 and this is the first video on chapter 18 one more video on this and that should complete this chapter inshallah foreign