Answer:
QED, Â EDQ, Â DQE, Â EQD, Â DEQ, Â QDE
Explanation:
The structure of all possible peptides that contain the given amino acids are :
QED, Â EDQ, Â DQE, Â EQD, Â DEQ, Â QDE
where : Asp is represented by the letter code D
       Glu is represented by the letter code E
       Gln is represented by the letter code Q
Note : when three amino acids combine they form what is known as tripeptide ( i.e. contains two peptide linkages ) while a peptide linkage is been formed by the combination of a carboxyl group of an amino acid and the amino group of different amino acid