Test Papers – National Board Exam (IX-X)
CLASS XII MH – PCMB Chemistry- Aldehydes Ketones Acids Demo Videos
Hello students we are starting with the most interesting chapter of 12 standard chemistry paper to the name of the chapter is aldehydes ketones and carboxylic acid students we are going to study this chapter in modules in this particular module we are going to discuss introduction and definition of a carbonyl group followed by classification of a carbonyl group and finally we are going to a structure of a carbonyl group so you’re we go with the first point that’s the introduction is wooden you know you can see one statement on a screen as aldehydes and ketones are known as carbonyl Compounds now student you may have got a thought what our carbonyl compounds the answer is a carbonyl compounds are those compounds which contains carbonyl group now students if you can see there is one more term what is carbonyl groups on a screen you can see a group which is actually a carbonyl group now student let’s do a little bit detailing of this particular group so you’re student can you see carbon atom of this group is sp2 hybridized one more point has to be discussed in this the carbon atom of this particular group is known as carbonyl carbon and the oxygen atom of this group is known as carbonyl oxygen so student this was just a brief introduction let’s now the final carbonyl group so students can you see over your a carbon atom is attached to an oxygen bar double bond not only this it is what one more feature can you see that two single bonds attached to a carbon atom that is nothing but what these two valence are actually free so if you combine both these statements you can define what is a carbonyl group so a group in which a carbon atom is attached to oxygen by a double bond and remaining two valence of a carbon atom are free is known as carbonyl group student this was just the introduction let’s move on to the next topic that’s a classification so you’re sort of we have got a carbonyl group know There are total to in all three basic compounds where the carbonyl group is Present Here the first one I have got a carbonyl group one side of the carbonyl group is an alkyl group are on the other side you have got another group called H these type of compounds are called as are the aldehydes the second compound again I have carbonyl group one side of the carbonyl group if I’ve got alkyl group and on other side also if I have got an alkyl group maybe same Or may be different these type of compounds are called as ketones finally the third 1 i have got Over here a carbonyl group one side of the carbonyl group I would an alkyl group on the other side of the carbonyl and group I’ve got on hydroxyl group which is OH group the type of compounds are called as carboxylic acids student Remember in all there are four more compounds where carbonyl group is present but since those compounds are obtained from carboxylic acids so we know them as Substituted acids let’s go in detail of those compounds so you’re I’ve got the first compound where it you can see a carbonyl group one side if you have an alkyl group on the other side if you have got an or our group which is called as alkoxy group these type of compounds are called as ester similarly I have got a carbonyl Group one side of the carbonyl have got an al alkyl group on the other side i have gotten halogen which is X these type of compounds are called as us acyl Halide then the next one again I have got a carbonyl Group one side if you see that is an alkyl group Other side that an nh-2 group that’s an amine group these type of compounds are called as amides finally I have got a group whereas to carbonyl group in between that is one oxygen atom either side of the carbonyl groups if I’ve got an alkyl group may be same or different these type of compounds are called as acid anhydride so student these last four compounds what we discussed they are as acid derivatives the student remember one thing out of the seven Compounds what you can see first two compounds are only known as carbonyl compounds and rest of those five they are not a carbonyl compounds since they have a carbonyl group but did not behave as a carbonyl group and the reason is due to resonance which we are going to discuss later on so you’re we end up with the classification let’s move to the next topic that’s a structure of a carbonyl group so you’re on the screen I have got a carbonyl group there you have a lone pair on oxygen atom if you see the Carbon atom and remember it’s sp2 hybridized and the bond angle would be nothing but 120 the geometry of this group will be nothing but triangular planner in our or we can call it as triangular planner are not only this one more point students a carbon atom if you see there are two single bonds single bonded they are Sigma bonds and between that carbon oxygen if you see one of the bond is Sigma and the second-bond is nothing but a PI bond so student this is something what we are going to discuss or we had discussed in this particular module thank you very much.
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CLASS XII MH – PCMB Biology -Gene Demo Videos
Hello students now let’s talk about the fifth part of the semi conservative replication of DNA here I were talking about the fourth step of replication which is called as synthesis of new strands that ok let’s start a look at this picture what do you see you guessed it right this was the same picture from the previous module we call it as the replication fork yes fine let’s check the orientation of the two strands one is reading from three prime to 5 frame and the other one is we read from three prime to 5 prime in the opposite direction is that ok now let’s bring back an enzyme here look at that enzyme what is this enzyme you know it it is DNA helicase that’s correct let us put the helicase into action and open the strength some more there you go and voila once again what did you see you simply saw the two strands of DNA now got almost completely Separated yes correct now let’s check the orientations once again you have the three prime five prime and you have the three prime five prime in the opposite direction for the two strands right now these both single strands can act as a template for synthesizing new strands is that okay for right now I’m going to just look at the left strand as a Template let us see how does this template strand make a new strand on itself right now for the purpose of replication we require a molecule called as RNA primer Right look at the name RNA primer what is a primer let’s see that a primer is a strand of shot on the sequence itself as a starting point for DNA synthesis right how cool is that you have an RNA but it synthesizes new molecule of DNA is that ok fine now this on the primer is synthesized by a special enzyme not shown here called as RNA primase so please remember RNA primer is synthesized by RNA primer the enzyme right now look at that are the primer carefully look at that symbol yellow right you know that if it was all arranged that would be thymine and that would be DNA but this is RNA so i changed the color to yellow and that yellow is what Uracil so and that’s why you know that is an RNA primer now what is this primer really really do let us see that next now this primer is known to attach to the three prime end of the template strand using the template strand yes you do do you see the three prime end now you do is that ok so let’s take the honor primer and put it on the three prime end of the template strand what would you do after getting attached there let’s see that next now these primers are known to attract complimentary nucleotides from the nucleoplasm let us see how it would do that look at that what do you see it is attracting complimentary nucleotides from the nucleoplasm and they should be complementary to what they should be complementary to the bases on that template strand but now it requires another enzyme to build that new strand let’s see what that enzyme, that enzyme is called as DNA polymerase remember DNA polymerase is the main replicating inside because it will replicate or to make the new strand of DNA and let us see how it would do that ,that’s the polymer is here it is scanning the template and it is adding the complementary base pairs and building up the new strand you can see how that is happening right look carefully yes i’m going to go ahead some more then again i’m going to add new bases in my new strand that a complementary to the template strand some more ahead some more bases so that’s what DNA polymerase does it scans the template and it keeps adding the nitrogen bases right complementary to the template strand ok now i have built a new strand i’m going to call this the new strand synthesized from five prime to three prime direction and this is how synthesis of new strand takes place notice something you’re very importantly the new strand of DNA is always synthesized from five prime to three prime direction which means the template strand should always be oriented from three prime to 5 prime direction you have to make note of this very important ok and this brings us to the end of the module number five on semi conservative replication of DNA in the next module I were talking about the sixth part of the semi conservative replication of DNA thank you and take care.
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CLASS XII MH – PCMB Biology-Human Reproduction Demo Videos
Hello students in this module we are learning an important process call as fertilization or syngamy now let’s see what this beautiful process is then we want to define fertilization students it is the process of what of fusion of haploid meal and female gamete to form what to fall deployed zygote with to n chromosomes students so this is what the definition of fertilization is but let’s do the detailing of fertilization when we talk about fertilization and human students it is internal that means it takes place inside the body of the female but very exactly inside the body of the female it takes place here and what is this point being pointed at this is the ampulla of the oviduct like the longest section oviduct fertilization occurs in the ampulla of oviduct and normally within the six hours of ovulation students now when we talk about fertilization millions of worms released during the insemination that is the release of semen in the vagina of the female around 300 million sperms released but only very few i capable of getting close to the egg and from those few only one gets to fertilize students and let’s see when we talk about fertilization after insemination activation of sperms takes place by Fallopian tube which releases of this viscous fluid but another important step before the actual process of fertilization takes place students is something we call as fertilizing , ant fertilize in reaction and what is that let’s see now what happens is the ovum-female ovum has a glycoprotein which secrete scholars fertilizing it recognized this human sperm because human egg needs to be fertilized by human sperm only so this chemical students recognizes another chemical on the sperm head which is call as antifertilizing which is produced by sperm head and once it recognizes that then only fertilization can proceed this process is one of the most important process before the fertilization callers fertilizing antifertilizing reaction students which is Highly, highly species-specific that means the sperm of any other organism any other animal cannot fertilized human egg now moving on to the details of the process students this is a human egg and let’s say the sperm which is trying to fertilize the Egg it has to penetrate or pass through three less outermost corona radiate then the second one the transparent ones zona pellucida and inner most students is the vitalline membrane to it needs to penetrate through these three layers and then only fertilization will be successful so let’s see the first layer corner radiator how does it pass through this it releases an enzyme a chromosome of the sperm students releases an enzyme called as Hyalurronidase acid which dissolves the cells of this layer remember corona radiate ourselves students were glued by the acid called Hyalurronidase acid that Hyalurronidase acid is destroyed by this enzyme called as Hyalurronidase now the second layer which is that zona pellucida, zone pellucida students has penetrated by the release of an enzyme called as a acrosin or zona lysin that dissolves this layers are two barriers cross now the third is which one vitalline membrane students was the sperm head the achromosome membrane touches the vitalline membrane the fuse together a Achrosome membrane the membrane and vitalline membrane fused together and that releases the nucleus of sperm inside the plaza immediately after the students second meiosis completes you remember egg of the female was arrested at metaphase 2 stage of meiosis to now it proceeds further and meiosis to complete so you can see that now there are two polar bodies that know by this time first polar body also divides to form another polar body so in the parry vataline Space you may see two or three polar bodies there now what happens after simultaneously with this is the vatelline membrane you can see transforms into a membrane which we call as the fertilization member and what is the purpose of that once fertilization membrane is form students No other sperm can penetrate through the egg now that means fertilization membrane is preventing polyspermy no other sperm can penetrate through the Egg now what happens to this is both the nuclear sperm nucleus and egg nucleus they absorb lot of water and they start growing inside and see that we call them Now pro nuclei sperm pronucleus fuses with the egg pronucleus we call this process as amphimixes or karyogoma. Karayo nuclious Gamy is marriage and students this is when we see a woman has conceived or she is pregnant now fertilization significance what for fertilization complete oogenesis it also determines the gender of the baby if the sperm having X chromosome fuses it’s going to be a baby girl and if it is y chromosome it’s going to be a baby boy also it restores diploydi the fertilization in turn was this proximus centriole or in the ovem also students it brings about genetically combination leading to Variation and the most important processes evolution so here then we completed fertilization students we are going to be the next module taking care of embryonic development until then take care.
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State Board Semi English Std IX Geometry Demo Videos
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StateBoard_Semi_English_Std_IX Sanskrit Grammar Demo Videos
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State Board Semi English Std IX Sanskrit Entire Demo Videos
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