This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Proteins and Amino Acids, Subject name: Biochemistry
In HbS, Glutamic acid replaced by valine. What will be its electrophoretic mobility? 
Select and explain. 
A. Increased, B. Decreased, C. No change, D. Depends on level of concentration of HbS
B: Decreased
Answer: B: Decreased 
Explanation: Ans. B. DecreasedIn HbS, Glutamic acid is replaced by Valine. Hence the negative charge is decreased. So HbS moves slower than HbA1.The relative mobility of various Hb fractions in Hb electrophoresis.Relative mobility of common Hb fractions from origin or point of application is1. HbA22. HbS3. HbF4. HbA1