Question

13. Which of the following will migrate the farthest when an electrophoresis experiment is carried out at pH 7?

a) Proline (pI=6.3)

b) Glycine (pI=6.0)

c) Serine (pI=5.7)

d) Histidine (pI=7.6)

e) Aspartic acid (pI=2.8)

Answer 1

Electrophoresis is a seperation technique based on mobility of ions in an electric field.It can be used to seperate mixture of amino acids.

Positively charged ions moved towards the negatively charged electrode.

Negatively charged ions moved towards the positively charged electrode.

Neutral particles will remain stationary.

At pH 7.0 Proline,Glycine,Serine,Histidine and Asparatic acid carry negative charge.These amino acids will move towards the positive electrode.

But an amino acid with higher pH value will migrate the farthest in electrophoresis experiment.

Here Histidine has higher pH i.e. 7.6

Therefore Histidine will migrate the farthest.

Ans: (d)