Question

2. Show the structures for the following peptides: a) AF b) AGV C) VGA () FA

Answer 1

These are the one letter abbreviations for amino acids in a peptide chain.

We know that amino acids have a amino group as well as a carboxyl group.

Amino group of one amino acid binds with carboxyl group of another amino acid and forms a peptide bond.

Generally in a peptide, left side is the amino end and right side is the carboxyl end.

Now, lets look at the given amino acids,

a)

AF means it is a peptide containing two amino acids A and F. There is a peptide bond between carboxyo group

A is the one letter abbreviation for Alanine.

F is the one letter abbreviation for Phenylalanine.

A is on the left that means it is on the amino end and F is on the right that means it is on the carboxyl end.

Now we need to draw the structure of Alanine and then connect a Phenylalanine to the Alanine through a peptide bond.

Saabonye amina 1roup OH OH CH3 CAlantne) Phenye alanine) Theree cold be a peptide bond between canbony group of alontne and amino grcoup of phenyk alonine

OHO CH2 peptide bond. Cstreacture of AF) amlno end ZH Carcboxyl end

b)

AGV means it is a peptide containing 3 amino acids.

A = Alanine

G = Glycine

V = Valine

A is on the left(amino end), G is in the middle and V is on the right(carboxyl group).

H2N H2N oH OH OH CH3 CH CH3 Cvaline) Calyeine) CAlontne These two wild These two oi chain Yorm a peptide bond form a oH CH3 CH2 CH3 (structurce of AGV) amino end ZI O Canbonk end

c)

VGA means it is a peptide containing 3 amino acids.

V = Valine

G= Glycine

A = Alanine

V is on the left(amino end), G is in the middle and V is on the right(carboxyl end).

H2N o H OH CH3 CH3 CH3 CAlanine) Calycine) C Valine) These two uwil These two i forem a peptide bond form a peptide hond. H27 OH CH2 CH2 CH2 structurce ot vGA) amino end 2I ond

d)

FA means a peptide containing two amino acids.

F = Phenylalanine

A = Alanine

F is on the left(amino end) and A is on the right(carboxyl end)

OH HO C Hz Cphenyt alontne) ( alanine) These tuwo will fortm a peptide bond. CHs H27 OH structure of FA) amino end 21 Cabebong end