Question

Se hidrolizeaza 100 grame din tripeptidul glutamil-valil-alanina.Aminoacizii se titreaza cu 500ml NaOH 2M.Care e puritatea tripeptidului hidrolizat?

Answer 1

tripeptid:  H2N-CH(COOH)-(CH2)2CO-NH-CH(C3H7)-CO-NH-CH(CH3)-COOH
C13H23N3O6      M = 317g/mol
nNaOH = 0,5·2 =1mol
tripeptid + 2H2O = H2N-CH(COOH)-CH2-CH2-COOH + H2N-CH(CH3)-COOH + + H2N-CH(C3H7)-COOH
nNaOH = 4n  tripeptid     ⇒⇒ n tripeptid = 1/4 = 0,25 moli   
m tr. pur = 0,25·317 = 79,25g
p = 79,25··100/100 = 79,25%