Question

un alfa aminoacid monoaminomonocarboxilic A contine 42,66%O.
a) identificati aminoacidul A;
b)scrieti formula plana a dipeptidei simple B pe care o formeaza aminoacidul A;
c) stiind ca grupele functionale din aminoacizi si peptide dau reactiile specifice lor, scrieti ecuatiile urmatoarelor reactii chimice:
A+HCL-->
B+HCL-->
A+CH3Cl-->
B+CH3Cl-->
A+NaOH-->
B+NaOH-->

Answer 1

R-CH(NH2)-COOH
32·100/M = 42,66      M = 75g/mol
mR = 75 - 13 - 16 - 45 = 1
⇒⇒ R = H      aminoacid : H2N-CH2-COOH
b) B:  H2N-CH2-CONH-CH2-COOH
c)H2N-CH20COOH + HCl ⇒ Cl⁻NH3⁺-CH2-COOH
H2N-CH2-CONH-CH2-COOH + HCl  =  Cl⁻H3N⁺-CH2-CONH-CH2-COOH
B + CH3-Cl  =  H3C-NH-CH2-CONH-CH2-COOH +HCl
A + CH3Cl  = H3C-NH-CH2-COOH + HCl
A + NaOH = H2N-CH2-COONa + H2O
B + NaOH = H2N-CH2-CONH-CH2-COONa + H2O