Question

At what pH would you carry out an electrophoresis to separate the amino acids in each mixture? (a) Ala, His, Lys (b) Glu, Gln, Asp (c) Lys, Leu, Tyr

Short answer

(a) Ala, His, Lys (b) Glu, Gln, Asp (c) Lys, Leu, Tyr Answer: (a) 7.0, (b) 4.0, (c) 6.5

Step-by-step solution

(a) Ala, His, Lys Separation

First, analyze the three isoelectric points given: Ala (6.0), His (7.6), and Lys (9.7). In order to separate these amino acids, we need to choose a pH that is in between the pI values. A good choice would be 7.0, slightly between Ala and His.

(b) Glu, Gln, Asp Separation

Analyze the three isoelectric points given: Glu (3.2), Gln (5.7), and Asp (2.8). In order to separate these amino acids, we need to choose a pH that is in between the pI values. A good choice would be 4.0, situated between Glu and Asp's pI values.

(c) Lys, Leu, Tyr Separation

Analyzing the three isoelectric points given for Lys (9.7), Leu (6.0), and Tyr (5.7). In order to separate these amino acids, we need to choose a pH that is in between the pI values. A good choice would be 6.5, the average between Leu and Tyr's pI values. To summarize, the pH values for separating the amino acids in each mixture are: (a) 7.0 for Ala, His, Lys (b) 4.0 for Glu, Gln, Asp (c) 6.5 for Lys, Leu, Tyr