Chemistry Chains Rings and Spectroscopy 09

TheTallOne

I can confirm that you need to know this reaction.

Typically aqueous HCl and heat and reflux. (You can have conc HCl, but any other H+ must be aq)

Hah I am well dumb..Better look that up tomorrow :o:

What topic is it under?

Reply 23

TheTallOne

18

Esma

Hah I am well dumb..Better look that up tomorrow :o:

What topic is it under?

I think it comes right after the HCN/KCN addition.

Basically it's a typical hydrolysis of proteins to amino acids.

Page 24, 43 and 50 if you have the 'Chemistry 2' text book.

Reply 24

TheTallOne

I think it comes right after the HCN/KCN addition.

Basically it's a typical hydrolysis of proteins to amino acids.

Page 24, 43 and 50 if you have the 'Chemistry 2' text book.

OOH It's the nucleophilic addition reaction..Yesss gosh I am so dumb I do know that one.Dunno why I didnt strike the association.Thanks for the page references and all,will definately look it up tomorrow seeing as I didnt get that as quickly as I should have really :p:

Reply 25

I looked it up today and realised that it was one of the steps of the two-step synthesis of Lactic acid which I hadnt gone over properly :smile:

I wanted to ask,what exactly do we need to know about L-Amino Acids?I was looking through the specification and saw that it was mentioned there in the optical isomerism bit..Anyone?

Reply 26

chud101

6

sacrificing my chains rings and spec exam!!!!! :biggrin:

! Im not going to do any revision for it, so that i can nail my biology exam first time :biggrin:

aw thats aloaod off my shoulders! as i would probally end up resiting in june anyway :biggrin:

Reply 27

equinox3o0o

2

lol l amino acids, i dont think so

Reply 28

Esma

I looked it up today and realised that it was one of the steps of the two-step synthesis of Lactic acid which I hadnt gone over properly :smile:

I wanted to ask,what exactly do we need to know about L-Amino Acids?I was looking through the specification and saw that it was mentioned there in the optical isomerism bit..Anyone?

Do you mean a-aminoacids (as in alpha?), otherwise I have never heard of an L-aminoacid :s-smilie:

Reply 29

EierVonSatan

21

JumpingJonny

Do you mean a-aminoacids (as in alpha?), otherwise I have never heard of an L-aminoacid :s-smilie:

L is a sort of notation for chiral molecules, it can either be L or D, with L being the natural version :smile:

From what I remember you do need to know about amino-acids for this exam.

Reply 30

DealerG

Esma

Hmm..
I don't recall seeing that reaction anywhere tbh..Maybe I am just extremely tired.
From what I remember,you add HCl(hot)to a compound,it will hydrolyse it splitting it into two different monomers..I.e. Protiens -> Amino Acids etc .. Basically just reversing a condensation/Addition-elmination reaction.. Non?
Someone clarify for me please..I'm wellll tired :sigh:

what, i thought it was HCL 6mol dm^-3 and water...

Reply 31

equinox3o0o

2

dilute acid and water

Reply 32

equinox3o0o

2

you are correct DealerG

Reply 33

DealerG

I'm taking a look at this http://www.ocr.org.uk/Data/publications/key_documents/L_GCE_Chemistry_Spec.pdf

Reply 34

EierVonSatan

L is a sort of notation for chiral molecules, it can either be L or D, with L being the natural version :smile:

From what I remember you do need to know about amino-acids for this exam.

Yes you do, along with zwitterions etc, but its more reactions involving amino acids, i.e. substitution reactions. Oh and some polymer stuff
Also so D is the second isomer synthesised in a lab? (i.e. not by the human body?)

Reply 35

DealerG

JumpingJonny

Do you mean a-aminoacids (as in alpha?), otherwise I have never heard of an L-aminoacid :s-smilie:

understand that chiral molecules prepared synthetically in the laboratory may contain a
mixture of optical isomers, whereas molecules of the same compound produced
naturally in living systems will often be present as one optical isomer only (for example:
L-amino acids).

it's there :frown:

Reply 36

EierVonSatan

21

JumpingJonny

Yes you do, along with zwitterions etc, but its more reactions involving amino acids, i.e. substitution reactions. Oh and some polymer stuff
Also so D is the second isomer synthesised in a lab? (i.e. not by the human body?)

Yeah D is the 'unnatural version' (well far less of it in nature anyway)

Reply 37

DealerG

understand that chiral molecules prepared synthetically in the laboratory may contain a
mixture of optical isomers, whereas molecules of the same compound produced
naturally in living systems will often be present as one optical isomer only (for example:
L-amino acids).

it's there :frown:

Oh okay, there is nearly always a question asking for the difference between the two.

Reply 38

EierVonSatan

Yeah D is the 'unnatural version' (well far less of it in nature anyway)

I don't understand this A and D stuff :frown:

Can you just give a brief explanation?

Reply 39