Heme group question

[thewax]

What is a heme group?

(Note: This is not a homework question) The progress I made: The textbooks that I have consulted only have heme in them. Similarly, the web has a lot on the definition of heme but I can't find any good website that defines a heme group.

[stopherlogic]

http://en.wikipedia.org/wiki/Heme

[thewax]

Thanks stopherlogic!

I'm sorry, but I just can't see the words "heme group" on the web page...
Are you sure wikipedia has heme group and not just heme????

[stopherlogic]

A heme/haem is a group so the terminology is interchangable. You don't need to put the word "group" on the end of it for it to mean the same thing. Hence when it says "heme is a prosthetic group" it could also say, "a heme group is a prosthetic group" it all means the same.

[thewax]

Okay... thanks!!!!!

[thewax]

Thanks for replying!

Just making sure:
My textbook lists heme and heme group as different entries. So they are still the same????
According to my textbook, a heme is a "Each subunit has a nonpolypeptide component, called heme, with an iron atom that binds oxygen." The definition does not include the word group. Could you explain it to me??????

[stopherlogic]

Heme is the non polypeptide component, it is not one atom so can therefore be described as a heme group. It is a prosthetic group which is bound to a protein but not a protein molecule itself. Don't get too hung up what to call it call it a "heme" or a "heme group".

[thewax]

okay...... thanks very much!!!!!!!!!!!!