Unless you have a truly sucky professor (I did not - I had the greatest biochem prof ever!!)
In less than 5 minutes I can draw all of them which sounds daunting until you try it:
start with the two carbon backbone
off the left side draw an N, with both Hs (yes, both - it makes sense when you start combining amino acids in a string which then form alpha helices, etc)
off the right side draw the carbonyl off the 2nd carbon and the OH group
There, you have the start for 19 amino acids... all except proline.
Glycine is boringly blank - nothing but an H off the primary carbon...
Alanine is almost as boring but has a methyl group...
Then throw in another carbon off the alanine and you have valine...
Eventually, you get this:
I left off the two acids because you simply replace the NH2 with COOH and you get the acids.
There you have it.
How will that help in biochem?
Well, if you know that the reactions of the amino acids combine via peptide bonds, disulfide bonds, H bonds, etc ... and know the pka of the acids, you can start to configure the quaternary structures and figure out:
if the pocket on a substrate has a basic inside, what can fit inside of it?
HINT: WON'T BE GLYCINE, et al ...
When it comes to the chymotrypsin reaction, knowing that histidine has a 5 member ring with two N in it, help remember the conformational change during the two cycle reaction...
Or when you get into creating urine, or why asparagus stinks in the urine ;)
Anyway, 5 minutes to do all that above ... taught to me by the greatest biochem prof ever !
