help with spotting polypeptide - Chads Ochem

[FutureDental88]

I cant see the bonds.. Could someone please fill them out on paint or something. Thanks !




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[mh0000]

the peptide bond forms an amide, so just split the carbonyl and nitrogen from the amide along the main chain. Or just count the number of carbonyl groups along the main chain to answer the question.

 

[FutureDental88]

So I just count the Amides from the main chain?

 

[mh0000]

So I just count the Amides from the main chain?

I would count the carbonyls of the main chain since the N-terminus does not form an amide and you may come up one short if you're not careful.

 

[FutureDental88]

well,,, the correct answer is 5... so if you count the main chain carbonyls, u will land on 6.. which is not correct?? But when I count the amides, I actually make 5....

Please correct me if im wrong.

 

[AlbinoPolarBear]

For number of amino acids in polypeptide, count carbonyls on main chain.

For number of peptide bonds, count amides on main chain.

 

[LetsGo2DSchool]

Dude, the best way is to understand the structure of a protein. It's not that difficult:

NH2-CHR-COOH

The peptide bond will occur between the COOH group of one protein and NH2 group of next protein. Look for this pattern on the main chain. Don't just count up carbonyls. Try to visualize one protein bonding to another on a main chain.

 

[FutureDental88]

Ok got it.. Thanks everyone !