Question

Assume that a particular amino acid has an isoelectric point of $6.0$. In a solution at $pH$ $1.0$, which of the following species will predominate?

• A.
• B.
• C.
• D.

Answer 1

The correct option is A

We see that the given condition is highly acidic because `pH=1`. This tells us that there will be a lot of free protons available in solution. Since `H^+` ions are available in solution, the `-NH_2` gets protonated easily and hence the protonated form is the most dominant species at said conditions.