Question

in part b, the ph of the tris-glycine buffer used is 9.2 and the pi of normal human hemoglobin (hbahba) is 6.9. what is the net charge on normal human hemoglobin (hbahba), heterozygous (hbahbs) and sickle cell hemoglobin (hbshbs)? which electrode should each sample migrate toward during the electrophoretic separation? (2 points))

Answer 1

The net charge on normal human hemoglobin (HbA) is zero at pH 6.9, as is the net charge on sickle cell hemoglobin (HbS). For heterozygous hemoglobin (HbAS), the net charge depends on the proportions of HbA and HbS. During electrophoretic separation, HbA and HbAS will migrate towards the anode, while HbS will not migrate as it is at its isoelectric pH.

Step-by-step explanation:

The net charge on normal human hemoglobin (HbA) is zero because at the isoelectric pH (pH = 6.9 for HbA), the positive charge on the amino acids in the hemoglobin molecule is equal to the negative charges, resulting in a net charge of zero.

For heterozygous hemoglobin (HbAS), there is one normal hemoglobin allele (HbA) and one sickle cell hemoglobin allele (HbS). The net charge on HbAS will depend on the proportions of HbA and HbS, and can vary.

The net charge on sickle cell hemoglobin (HbS) is also zero because the isoelectric pH for HbS is the same as that for HbA, which is 6.9.

During electrophoretic separation, both normal human hemoglobin (HbA) and heterozygous (HbAS) samples will migrate towards the anode (+ve electrode) because both have a net charge of zero at the pH used. Sickle cell hemoglobin (HbS), with a net charge of zero at the pH used, will not migrate towards either electrode as it is at its isoelectric pH.