Question

For the following amino acids - explain why the overall charge on the amino acid is different at PH's 2, 7, and 11. Relate it to the pk, of the groups on the molecules To achieve distinction, you must explain that the form of an amino acid, whether positively charged, negatively charged or neutral, depends on the pH of the solution and also on the Ka of the acid group

Answer 1

fant pk for COOH going Kw=+ 6.3x pa sa araw gw G lutamic acid CE) N-M-CH2-CH2-COOH Pka, - 18-24 ? W 6. 8-9.8 COOH kw kb Hks - Side chain value brs 4.25 6. bo 2 lasu are they when given pH <pka do , her protonatien takle К. 1.9 соон other cool αμνμν pΗΣ Ρk, Se, here deprotonation takle flow 600 ~NH₂ # on a single pH protonation & dekrotonation cann't take sa simultaneously for Glutami Saeed (E). - pH=2 pH = 7 for NH ₂ pke > PH So, for pH=7 I for cook in side chair to protonation take for Cook, pH> bks - pks (pH place so, t1. So, deprotonation taku deprotonation takeplay play so, -1. So. 1 day on COO Positively charged I take for pko, as well phypka, enph 12 so, heve depretenation - I fou play, bh> bkan Net charge = (-2) deprotonation take peace, "ON Sed and negatively charged at that inet change =(-2) negatively changed at pH= 11. OzЕС