 Now coming back to quiz number two and how we actually look into that the quiz number two the question was again that you have a amide bond present in a protein and this amide bond actually absorbed in the region of 175 nanometer to 230 nanometer and more interestingly the pi to pi star transition and into pi star transition these are the two primary transition that actually occurs so pi to pi star transition that generally occurs 175 to 190 195 nanometer region that may differ a little bit depending on what is overall structure and whereas the into pi star transition that actually occurs around the region of 220 nanometer so this figures I'm saying it is kind of that the central part of the absorbance by the maximum so what there you can see that when you look into a CD graph when you look into a CD graph and how it actually looks like and we can see that for alpha helix it has a band structure like this but these are actually coming at 208 nanometer 222 nanometer something around that region the CD graph so over there you can see that it is comes around 195 nanometer or so so all this peaks actually coming from pi to pi star into pi star transition so what is but that actually planar and a planar molecule already has a sigma plane so it shouldn't be CD active the way we have studied so why it is still being CD active the answer lies that it is actually having these two alpha carbons sitting next to each other which are actually optically active and they actually induce CD activity or in the other term chirality on this amide backbone so that was the main concern that is actually happening over there and over there how it is happening so if you look very closely this is the electric dapplement for the carbonyl somewhere around here is the end to see pi star transition which is coming from the lone pair of the nitrogen so both of them are active so altogether what happens the actual dapplement for this system because they're conjugated lies somewhere around this red line and now that is actually having an angle other than 90 degree with respect to the CD active bands coming from this alpha carbons I am drawing that in helical because there the new electric and magnetic both are actually active whereas in the red region only new electric is active for the end to pi star pi to pi there is no mu M active however this blue line and this red line actually combined together and that is why this interaction of the end to pi star or pi to pi star they also become optically active because that is actually having some influence coming from this this chirally active alpha carbon center and because they have an angle between them and not 90 degree angle so they become optically active and that is known as the induced chirality so over there in this system when we are she looking for the answer things you have to write that okay the pi to pi star and into pi star are planar not really optically active so where this optically activity is coming to so one thing you have to say is that it is coming from the induced chirality from the alpha carbon that is one point and secondly you have to influence a bit how it is actually influencing and that is coming from this dipole moment interaction so if you can write it in one of the other language that is so that is the two points I was actually looking for and I have shared your marks with all of you if you have any query or question please let me know but the friend from asking question like my friend they probably write totally wrong I believe I should get more number so please leave that thing to me like who has written what and let me decide which will be the best way to provide the marks to you and what will be the best way to judge you at this particular point and I can actually assure you like what you have done and where you can actually improve so there is no point of comparing me with the other because you haven't seen the answers for each of you that is what I've seen by myself so let that judgment line to me and you have to believe me that I am being fair with all of you there is no partiality among each of you and with respect to that that mass has been terrible and all of you actually already got a good amount of marks in that respect so don't need to hurry too much because that is not going to affect your overall grade too much because the average here number if I believe it is close to 8.5 so it is very close to the full marks in this so most of the mass which is going to affect your grading will be probably the interim exam so that is where you have to put a lot of effort over there and write the answers properly so over there any questions any quiz or any assignment I am giving to you you have to ensure that it is not about you have to write this particular way or this particular thing you can write in different ways you can write an answer multiple ways that is totally fine but you have to ensure that you are writing according to the what is the question has been asked and answer it or provide your logic accordingly that is what I am giving for say I am writing you to write that induced chirality inducing activity even if you don't write this particular terms but in your own words you have mentioned the same thing I am happy with that so try to understand the question properly and then try to answer