an enzyme is heated

Discussion of all aspects of biological molecules, biochemical processes and laboratory procedures in the field.

Moderators: honeev, Leonid, amiradm, BioTeam

Post Reply
candice
Garter
Garter
Posts: 4
Joined: Fri Jul 04, 2008 1:42 am

an enzyme is heated

Post by candice » Mon Jul 14, 2008 5:02 am

which bonds are the last to break when an enzyme is heated?

A)disulphide B)hydroen C)hydrophobic interactions D)ionic

User avatar
canalon
Inland Taipan
Inland Taipan
Posts: 3909
Joined: Thu Feb 03, 2005 2:46 pm
Location: Canada

Post by canalon » Mon Jul 14, 2008 4:25 pm

What do you think.
For me the answer is none of the above, because if you heat enough you can break the atoms beyond that, but that's just me and I don't ask anyone to do my homework on the net. So prove you work, share your doubts and you will find help, post your question and hope for a free lunch, and you will get sarcasm.
Patrick

Science has proof without any certainty. Creationists have certainty without
any proof. (Ashley Montague)

MisterATP
Garter
Garter
Posts: 38
Joined: Tue May 13, 2008 7:49 pm

Post by MisterATP » Mon Jul 14, 2008 5:00 pm

When a protein is denaturated by heating, it loses the structures in this sequence: quaternary-->tertiary--->secondary--->primary. So answer is b)hydrogen ( secondary structure; primary structure is supported by covalent bonds).

Cat
King Cobra
King Cobra
Posts: 635
Joined: Thu Feb 14, 2008 7:40 pm

Post by Cat » Mon Jul 14, 2008 5:33 pm

I agree with MisterATP for the most part, but the answer has to be disulfide bonds.

Ionic interactions are the 1st to go, hydrogen and hydrophobic both support secondary structure, disulfide bonds are covalent and not easily destroyed by heat (if they are affected at all).

MisterATP
Garter
Garter
Posts: 38
Joined: Tue May 13, 2008 7:49 pm

Post by MisterATP » Mon Jul 14, 2008 8:16 pm

Yes, I think my answer isn't right. I have forgotten one thing: hydrogen bonds are in quaternary structure yet! So it isn't a need to go on secondary structure as I wrote.

The quaternary structure is supported by ionic, disulphide, van der Valse and hydrogen bonds. But hydrophobic bonds appear just in tertiary structure. So according to sequence I wrote, answer would be c) hydrophobic interactions.

Cat
King Cobra
King Cobra
Posts: 635
Joined: Thu Feb 14, 2008 7:40 pm

Post by Cat » Mon Jul 14, 2008 10:23 pm

To clarify:

you are correct in your order, but disulfide bonds are exception to the 'rule'. They are covalent bonds and would break out of order.

User avatar
MrMistery
Inland Taipan
Inland Taipan
Posts: 6832
Joined: Thu Mar 03, 2005 10:18 pm
Location: Romania(small and unimportant country)
Contact:

Post by MrMistery » Wed Jul 16, 2008 9:17 am

Cat is right.
@Candice: the best to approach this question is from a chemistry perspective: look up each type of bond in a chemistry book or on the internet and you will discover that disulfide bonds, being covalent, are the hardest, and therefore last to break. But that is a bit harder than asking for the answer
"As a biologist, I firmly believe that when you're dead, you're dead. Except for what you live behind in history. That's the only afterlife" - J. Craig Venter

Post Reply

Who is online

Users browsing this forum: Bing [Bot] and 9 guests