Explain the role that basic amino acid side chains play in the maintenance of protein structure and explain the most critical factor that affects their ability to perform this role.

Question

aaronq · Answer

They affect the secondary and tertiary structures of proteins.

aaronq · Answer

http://en.wikipedia.org/wiki/Protein_secondary_structure http://en.wikipedia.org/wiki/Protein_tertiary_structure i'm not gonna re-write what's already been written

aaronq · Answer

If you have specific questions i'm sure @Frostbite or I could answer them

anonymous · Answer

okay thanx

anonymous · Answer

i dont understand product inhibition and feedback inhibition how it works and again the Km, Vmax and all that stuff in michaelis-menten graphs and lineweaver-burk graph #help

frostbite · Answer

It is a very big question.
But I'll try to make it short:
Enzymes are usually not just able to catalyze a reaction one way, it can be done both ways (however one way not as effective). So the product can work as an inhibitor for the reaction we are looking at.
Feedback inhibition is when one or more molecules in a pathway inhibit a enzyme that catalyze the pathway.
In general we say there are 3 major inhibition types
1) competitive inhibition
-the inhibitor binds only to the active site of the enzyme and thereby inhibits the attachment of the substrate.
2) uncompetitive inhibition.
-the inhibitor binds to a site of the enzyme that is removed from the active site, but only if the substrate is already present.
3) non-competitive inhibition (mixed inhibition)
the inhibitor binds to a site other than the active site, and its presence reduces the ability of the substrate to bind to the active site.

To look at the effects of $K_{M}$ and $V_{max}$:
1) $V_{max}$ constant, $K_{M}$ incresses.
2)  $V_{max}$ incresses, $K_{M}$ constant.
3) Both $V_{max}$ and $K_{M}$ increase
We can determine this easily from a Lineweaver–Burk plot, by looking at the slopes and $y$-interceptions

frostbite · Answer

I suppose you are familiar with the Lineweaver–Burk equation in order to make the plot?

frostbite · Answer

Sorry did not mean that Vmax was increasing, but it decreases.

frostbite · Answer

But a good web side to get some more info why this is would be here: http://fdslive.oup.com/www.oup.com/orc/resources/chemistry/qchem/01student/graphs/source_files/P726C12.html And if that is confusing @aaronq or I can explain it.

anonymous · Answer

thnx man i followed the link

frostbite · Answer

No problem. I hope it helped!