Amino Acid Reactivity

Question 1

What does it mean for an amino acid to be amphoteric?

Answer 1

it can act as both a base and an acid

Question 2

What is the Henderson-Hasselbalch equation?

Answer 2

a mathematical formula that describes the relationship between pH, pKa, and the position of equilibrium in the acid base reaction

Question 3

When the pH of the solution is less than the pKa of the acidic group what will occur in regards to amino acids?

Answer 3

the acidic group will mostly be in its protonated form

Question 4

When the pH of the solution is greater than the pKa of an acidic group, what will occur in regards to amino acids?

Answer 4

the acidic group will mostly be in its deprotonated form

Question 5

For amino acids, in its protonated/acidic form, what is the amine called and what is its pKa range?

Answer 5

ammonium group, pKa 9-10

Question 6

What is a zwitterion?

Answer 6

a molecule with positive and negatives charges that balance (also konwn as a dipolar ion)

Question 7

What is the isoelectric point?

Answer 7

pI = the pH at which a molecule is uncharged/zwitterionic

Question 8

How can you calculate the pI of an amino acid?

Answer 8

if the molecule has two functional groups then you can just average the pKas