a, Circle the peptide bond in the structural diagram
b, How many monomers are there in this polymer?

Question

a, Circle the peptide bond in the structural diagram 
b, How many monomers are there in this polymer?

anonymous · Answer

attachment

anonymous · Answer

The peptide bond I circled on the picture is wrong

anonymous · Answer

I count four monomeres.

blues · Answer

Yes, there are four monomers joined by three peptide bonds...

anonymous · Answer

Is monomer just anything branch out from the C

anonymous · Answer

which one is the peptide bond..

blues · Answer

No, the monomer is the entire peptide: backbone and side chain bonded to the alpha (or central) carbons.

anonymous · Answer

is it possible for you to circle it out.. cuz i dont really get it still

blues · Answer

The peptide bonds are formed between the amino group of one monomer and the carboxyl group of the other monomer - so it forms between the nitrogen of the first monomer and the carboxyl carbon of the second monomer.

I really don't want to try to draw on OpenStudy's image platform...

anonymous · Answer

That sould do it ;)

anonymous · Answer

ohh ok i see it ! 
umm.. can u circle out the monomers too...

blues · Answer

The whole monomer consists of the three backbone atoms (the carboxyl carbon, the alpha carbon and the nitrogen) and the side chain attached to the alpha carbon...

Or do you want just the side chains?

anonymous · Answer

I think is the whole monomer
the answer is 4 , yeah
but still kind of confuse which one is whihc

anonymous · Answer

To make it easy, number of side chains equals number of monomers in this case.

anonymous · Answer

and i dont really know what is alpha carbon...is it just normal carbon

anonymous · Answer

ohh ok, so i will just count the side chains then

but blues , u said the monomers have nitrogen, so is it also the same as counting how many nitrogens there are?

anonymous · Answer

And thanks mathhias and blues for you help :)

blues · Answer

The alpha carbon is the carbon in the backbone which is bonded to the carboxyl group on one side, the amino group on the other, the side chain and a hydrogen to complete it's octet.

Yes, each monomer has an amino group (which contains a nitrogen). It's not part of the side chain, it is part of the backbone.

anonymous · Answer

ohh ok . i'm clear now! thank you both!