Chemistry 3/4 Questions

[#1procrastinator]

First question - what are the key things that need to be memorised about the analytical techniques/methods? It's unlikely that I'm going to memorise the whole page

[charmanderp]

Which technique corresponds to which type of analysis. For example pretty much anything which involves the analysis of metal content will be conducted via AAS.

[Tonychet2]

you need to know exactly how each technique differs from each other one so e.g

NMR is to do with the nuclear spin states
and IR is to do with the bonds between atoms
AAS with electrons being promoted etc


so you can apply the knowledge to questions

[#1procrastinator]

Are only alpha-amino acids present in food? I have a multiple choice question that asks for the amino acid least likely to be obtained by the hydrolysis of protein in food and the only option that is different from the others is the one that isn't an alpha-amino acid...it's right, but I can't find any theory on this in my text

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A tripeptide forms between two aspartic acids and one tyrosine, how many different tripeptides could possible be formed? If A=aspartic acid and T=tyrosine, then

A-A-T
T-A-A
A-T-A

But the answer says 6...how do you get 6? Does it matter which aspartic acid molecule is on which side?

[ggxoxo]

I would have thought only 3 wold have been able to form

[AllAboutTheLGs]

It should be 3. Its only 6 if they were 3 different ones using factorials.
And I believe that alpha amino acid question is way beyond the scope of the course... never seen that before

[charmanderp]

Amino acids other than those in the data book are indeed outside of the course. But fun fact, they're found in things like snake venom and will most likely kill you, so don't consume them :p

[#1procrastinator]

Thanks guys

With the amino acids question, it's actually question 11 from the second 2006 exam, so yeah, probably some different course content
http://www.vcaa.vic.edu.au/vce/studies/chemistry/exams/2006/2006chem2-w.pdf

[charmanderp]

That one would be pretty obvious now though - option C isn't in the Data Book!

They're called beta-amino acids, by the way. In case you were curious.

[charmanderp]

It should be 3. Its only 6 if they were 3 different ones using factorials.

You still use factorials; it's 3!/2!.