According to the Diagram, Which Estimate is BEST of This

Question

According to the diagram, which estimate is BEST of this amino acid's isoelectric point? 
A) 0.5 
B) 1 
C) 1.5 
D) 6 
E) 11

Accepted Answer

The isoelectric point (pI) is the pH at which a molecule carries no net electrical charge. From the diagram, we can estimate that the pI of this amino acid is between pH 5 and pH 7, which means it is closer to a neutral pH of 7. The closest option is D) 6, which is a reasonable estimate for the pI based on the given information. The other options are either too low or too high to be the best estimate for the pI.