polypeptides (1 Viewer)

[iambored]

ok, a polypeptide is a protein??? (as it is made up of many small units of amino acids) is that right??

so are all proteins polypeptides?




and also, to separate amino acids you use chromotography? so what about before that, is it true that you have to break down the protein into amino acids? i don't think it's a dot point, but does anyone know how it's done?

 

[Huy]

See: biology forum/babydoll

 

[iambored]

um, ok but this is chem, i will look though

ok found it, thanks
http://www.boredofstudies.org/community/showthread.php?s=&threadid=14910
but the posters have conflicting views
and one conflicts with me as well...

 

[mercury]

bipeptide = two amino acids linked together, the C terminal links to the N terminal

the C terminal is the COOH end, the N terminal is the NH2 end.

polypeptides similarly means many amino acid units linked together through peptide bonds. Proteins consist of amino acids as you should know, so yes, proteins consist of polypeptides.

Proteins have primary, secondary, tertiary and quarternary structures. Primary structure is the way the amino acids are sequenced. Secondary structure refers to the way long chains of molecules are arranged. Tertiary structure determines overall shape of protein, glopular, long or narrow. Quarternary structures is basically the 3D shape of it.

Breaking the protein down is called denaturation and there are many ways to do this. Gas chromatography, electrophoresis, edman degradation... seriously, it's not just in a few words how protein is breakdown into amino acids in laboratory..... if you really really want to know in detail, consult books =p

 

[FLR-IT]

Originally posted by mercury

Breaking the protein down is called denaturation and there are many ways to do this. Gas chromatography, electrophoresis, edman degradation... seriously, it's not just in a few words how protein is breakdown into amino acids in laboratory..... if you really really want to know in detail, consult books =p

denaturation is not all that


The process of denaturation occurs by the following
heating - weakens H-bonds
changing pH - affects ionic attraction
shaking - increases thermal energy which is heat
adding cheimcals - changes protein structure


as for what mercury posted i do not noe how they work, they are not apar of the syllabus

 

[iambored]

thanks

Originally posted by FLR-IT
The process of denaturation occurs by the following
heating - weakens H-bonds
changing pH - affects ionic attraction
shaking - increases thermal energy which is heat
adding cheimcals - changes protein structure

is this part of the syllabus?

 

[FLR-IT]

yes it is

 

[iambored]

what?? damn, gotta find that

 

[ballerinabarbie]

hmmmmm what about adding enzymes? don't they help to break down a protein into it's amino acids

 

[iambored]

yeah, that's what i had, not that other thing, they hydrolyse (sp?) the decomposition is what i had

 

[phenol]

naah denaturation is just making the peptide chain lose or change its chemical abilities.

usually you use sodium dodecyl sulfate which screws up intermolecular interactions

not necessarily heat shake etc.

gas chromatography has nothing to do with denaturing, sorry

 

[mercury]

Originally posted by mercury
Breaking the protein down is called denaturation and there are many ways to do this. Gas chromatography, electrophoresis, edman degradation...

EDIT:

Denaturation - see phenol's explanation

Electrophoresis - used to separate macromolecules like protein, carried out in gels.

Gas chromatophray - My apologies... it does NOT have anything to do with denaturing. What i meant to say was gel filtration chromatography which is also used for separation of proteins (based on size).

Edman degradation - used for amino acid sequencing.