When two amino acids combine and the carboxyl group of the first amino acid reacts with the amino group of the second amino acid, what is the most accurate description of the end product?

A di-peptide and carbon dioxide
A di-peptide and water
A polypeptide
A protein

Question

When two amino acids combine and the carboxyl group of the first amino acid reacts with the amino group of the second amino acid, what is the most accurate description of the end product?

 A di-peptide and carbon dioxide
 A di-peptide and water
 A polypeptide
 A protein

aaronq · Answer

$\sf 2 ~H_3N^+\underbrace{C}HRCOO^-\rightleftharpoons H_3N^+CHR\underbrace{CONH}CHRCOO^- +H_2O$ 
        $\sf \alpha$-carbon                             amide (peptide bond)

somy · Answer

can we have a protein consisting of 2 amino acids? @aaronq

somy · Answer

sorry for the stupid question T_T

aaronq · Answer

it wouldn't be called a protein, it would be called a dipeptide (di means two)

somy · Answer

hmmm i thought dipeptide is  about having 2 peptide bonds

aaronq · Answer

nope, a dipeptide has 2 amino acids

aaronq · Answer

1 peptide bond

somy · Answer

oh okay noted thnx @aaronq ♥

anonymous · Answer

That would mean that it was a dipeptide and water?

aaronq · Answer

no problem @Somy :)

and yes, that would be correct @theninthgradeninja

anonymous · Answer

Ok, thank you... that really helped a lot..

aaronq · Answer

no problem. good stuff!