The Student Room Group

Scroll to see replies

Original post by kuku2013
ohh right I see thanks the bond between amino acids is a peptide bond right?

i think so yes :smile:
does anybody have a reactions and conditions table, or a link to one? thanks :smile:
Reply 2162
Original post by Chemistry95
i think so yes :smile:


do we have to memorise producing a chromaogram, if so how can we brief it down
Is there any step by step guides on how to do lon NMR or carbon 13 questions?
What hydrolysis reactions do we need to know?
Reply 2165
if I just about get grade A in f325 and close to full marks in f324 does that mean I have a chance of A* overall
Reply 2166
Original post by kuku2013
if I just about get grade A in f325 and close to full marks in f324 does that mean I have a chance of A* overall


yes, you need to get around 270 in total!
Original post by kuku2013
if I just about get grade A in f325 and close to full marks in f324 does that mean I have a chance of A* overall


unlikely as f325 is worth more, and also have to remember the practical skills assessment aswell
Reply 2168
are we meant to know ALL the key words in the book?
Reply 2169
Original post by Sinkim
yes, you need to get around 270 in total!


does this include coursework?
Hi, can someone explain to me if an amino acid that has an R group of NH2 or COOH can form a zwitterion?
Cause with a zwitterion the charges are supposed to balance, and if it has 1 negative group and 2 positive groups/vice versa, how is it a neutral molecule? I read on a past paper that if it has e.g. an extra NH2 group, it would make the isoelectric point more basic (I think), because the amino acid is more strongly basic. But how can an isoelectric point exist if it can't form a neutral zwitterion?
Any help much appreciated :smile:
Reply 2171
Original post by AFC_123456789
why do alcohols have a shorter retention time than alkenes



they are less soluble in the mobile phase used
Reply 2172
do we need to know how tlc and gc chromatography works? like the way the solvent moves up the stationary phase etc etc.
Reply 2173
How do you calculate aprox what UMS needed in unit 4 to get an A overall?
Original post by otrivine
do we have to memorise producing a chromaogram, if so how can we brief it down


my tutor never told us we have to so i'm going to say no
Reply 2175
Original post by kuku2013
does this include coursework?


yes. there is no way you can get 270 from exam alone remember the big one is 150UMS and the small one is 90UMS hence together they add up to around 240 UMS
Reply 2176
Original post by Sinkim
they are less soluble in the mobile phase used


So could you just say more soluble in the stationary phase?
Reply 2177
Original post by Vhai
Thanks but how did u do that?


Split it up into it's individual amino acids, then look at the table which shows you the R groups of each amino acid.
Original post by sidmanny
Hi, can someone explain to me if an amino acid that has an R group of NH2 or COOH can form a zwitterion?
Cause with a zwitterion the charges are supposed to balance, and if it has 1 negative group and 2 positive groups/vice versa, how is it a neutral molecule? I read on a past paper that if it has e.g. an extra NH2 group, it would make the isoelectric point more basic (I think), because the amino acid is more strongly basic. But how can an isoelectric point exist if it can't form a neutral zwitterion?
Any help much appreciated :smile:


Only one of the NH2 or COOH groups gets a charge. It doesn't matter which one you give the charge to as long as there is a positive and negative charge in the overall zwitterion
Original post by mrmccarl
do we need to know how tlc and gc chromatography works? like the way the solvent moves up the stationary phase etc etc.


i think we need to know briefly yes

Latest