At the PH Found in Cells About 7

Question

At the pH found in cells about 7.0), what happens to the amino group on an amino acid?
A) It acts as an acid and loses a proton, giving it a negative charge.
B) It remains neutral, like water, and does not have a charge.
C) It is reduced and tends to act as an electron donor in redox reactions.
D) It acts as a base and gains a proton, giving it a positive charge.

Accepted Answer

At a pH of around 7.0, typical of intracellular conditions, the amino group (-NH2) of an amino acid acts as a base and accepts a proton, becoming -NH3+ with a positive charge.