Exams..
Well I'm actually quite stressed now. First time since 28 Nov 2003 to be stressed over an exam. How about that.I kind of underestimated the power of the the biochemistry paper that I am supposed to take tomorrow. When I first started preparing for it I downloaded the 2004 paper and it was pretty easy. So I thought, oh well, if that is the standard, I can certainly breeze through it...
Then I went to download the 2003 and 2005 papers to do. It seems easy enough on the surface, but there are questions like these here:
1. True or false: The Standard Free Energy Change of a reaction at equilibrium is zero.
Well, you know very well the answer is FALSE, because Standard Free Energy Change = -RTlnKeq. But if you are not careful, will you be REALLY tempted to put TURE?!
2. Phosphorylation of amino acid side chains is an important mechanism for regulating protein activity. Which amino acid(s) most likely undergo phosphorylation?
a. Ser b. Thr c. Tyr d. Ser, Thr e. Ser, Tyr f. Thr, Tyr g. Ser, Thr, Tyr
I know that Serine gets phosphorylated the most frequently, followed by Threonine and Tyrosine. Well, base on this knowledge, which answer will you pick? A or G?! I will need my pencil to help me decide on this. Please help me decide if you can.
3. Two or more different proteins often associate to effect a biological function.A statistical examination of the structures of protein-protein complexes revealedthat certain amino acids occur more frequently at the protein-protein interfacethan one would expect by chance. (The protein-protein interface is the surfaceshared between the two associating proteins). Which amino acids do you thinkwere found at the interface? (Hint: think about what you know about the forcesthat govern protein folding and structure)
This can really fight with Hwa Chong Bio. Even after you have studied, the most you can do is 'make a informed and logical guess and convince yourself that your reasoning is right'. And I fully believe that I got A for Bio in prelims because my lucky star shone on me and made all my reasoning the same as my teachers'.
This is really really freaky... and there is NO ANSWER KEY.
And the worst thing is, after hearing all the stories from seniors that they did not do well for their biochem and stuff, I went to practise their paper and compared my answer to theirs... and I found that they are almost exactly the same!! So the only logical conclusion would be, if I took their paper with them, I would be screwed too :
Now I am feeling like as though I am going to take a HC Bio paper without tutorials, without excellent lecture notes (HC bio lecture notes are superb), with a rather bad textbook (I would not recommend Berg really. If you want a good Biochem text, get Lehninger. My mentor recommended it strongly and I find that some parts of our lecture actually comes from Lehninger.), without Mrs Foo, Mdm Tan, Mrs Tan and other teachers whom you can even SMS to ask questions, and without people like Songyu and Joyce whereby you can start hours long discussions with while trying to sort out confusing ideas.
What do people here discuss about? Well I'll quote an example from the bulletin:
Dear Professor Hill,
Why does the slope the lineweaver-burk plot for Uncompetitive Inhibition
remain Km/Vmax (i.e. unchanged from the slope of the graph for no
inhibition)?
Well, if you know what is a Lineweaver-Burke plot, the formulae associated (which are all covered in lectures and the book) and the concept properly, just rearrange the formula and you will know that the coefficients governing inhibition cancel out when you are finding the gradient!
Haiz. The Bulletin is useful nevertheless, as there are also certain questions which I do not know the answer so I can learn from those too. And I have also posted some doubts so that I can get clarifications from the professor. But still, tutorials are much more interactive...
And I fully acknowledge the fact that not all people are dumb and lazy. Most certainly are not in JHU.
So I'll see how I'll do for the first exam. Hoping for the best... off to sleep now...
