a. Write the equilibrium reaction to show the amphoteric behaviour of alanine in H_(2)O. b. Calculate the isoelctric pH of alanine, given pK_(a1, of cation of "alanine"=2.3 "and' pK_(a_2) of anion of alanine=9.7. c. Write equilibrium reaction for the dissociation of lysine, a basic amino acid and calculate its isoelectric point. pK_(a_1) of lysine with net (+2) charge=2.18 pK_(a_2) of lysin with net (+1) charge=8.95 pK_(a_3) of lysine with net (-1) charge=10.53 d. Write the equilibrium reaction for the dissociation of aspartic acid, an acidic amino acid and calculate its isoelectric point. pK_(a_1) of aspartic acid with net (+1) charge=1.88 pK_(a_2) of aspartic acid with net (-1) cahrge =3.65 pK_(a_3) of aspartic acid with net (-2) charge=9.60

a. Write the equilibrium reaction to show the amphoteric behaviour of

1.	a. Write the equilibrium reaction to show the amphoteric behaviour of alanine in H_(2)O. b. Calculate the isoelctric pH of alanine, given pK_(a1, of cation of "alanine"=2.3 "and' pK_(a_2) of anion of alanine=9.7. c. Write equilibrium reaction for the dissociation of lysine, a basic amino acid and calculate its isoelectric point. pK_(a_1) of lysine with net (+2) charge=2.18 pK_(a_2) of lysin with net (+1) charge=8.95 pK_(a_3) of lysine with net (-1) charge=10.53 d. Write the equilibrium reaction for the dissociation of aspartic acid, an acidic amino acid and calculate its isoelectric point. pK_(a_1) of aspartic acid with net (+1) charge=1.88 pK_(a_2) of aspartic acid with net (-1) cahrge =3.65 pK_(a_3) of aspartic acid with net (-2) charge=9.60
Answer» SOLUTION :a. b. `PH` at ISOELECTRIC point `(pI)=((pK_(a_1)+pK_(a_2)))/(2)=(2.3+9.7)/(2)=6` The isoelectric point `(pI)` is the `pH` at which the amino ACID exists only as a dipolar ion (armpholyte or zwitterion) with zero net charge. c. `:. pH` at isolectric point `(pI)=((pK_(a_2)+pK_(a_3)))/(2)=((8.95+10.53))/(2)=9.74` `:. pI=9.74` d. `:. pH` at isoelctric point `(pI)=((pK_(a_1)+pK_(a_2)))/(2)=((1.88+3.65))/(2)=2.77` `:. pI=2.77`