Understanding Zwitterions and Amino Acid Charge

What is the correct form of an amino acid in nature?

• Neutral form

• Zwitterion form

• Cationic form

• Anionic form

What does the PKA value of an amino acid indicate?

• The molecular weight of the amino acid

• The solubility of the amino acid in water

• The pH at which the amino acid is neutral

• The pH at which the amino acid gains or loses a proton

Which equation helps in understanding the relationship between pH and PKA?

• Henderson-Hasselbalch Equation

• Arrhenius Equation

• Van't Hoff Equation

• Nernst Equation

What happens to acetic acid in a basic solution?

• It becomes protonated

• It remains neutral

• It forms a zwitterion

• It becomes deprotonated

What is the charge of methylammonium at a pH lower than its PKA?

• Positive

• Negative

• Neutral

• Zwitterionic

At what pH is glycine expected to be in its zwitterion form?

• pH 1

• pH 13

• pH 7

• pH 9.6

What is the net charge of glycine at a pH of 1?

• -1

• +0.5

• +1

• 0

How does the charge of glycine change as pH increases from 1 to 7?

• It becomes more positive

• It becomes more negative

• It remains the same

• It fluctuates randomly

What is the charge of glycine at a pH equal to its carboxy group's PKA?

• -0.5

• +1

• +0.5

• 0

What trend is observed in the charge of glycine as pH increases beyond its PKA values?

• It remains constant

• It becomes more negative

• It becomes more positive

• It becomes neutral