Lecture 8: Amino Acids / Acid Base

Question 1

the ___ ionized form of an amino acid is the predominant form at physio pH

Answer 1

fully

Question 2

the acidity of a molecule relates to the __ of the conjugate base

Answer 2

stability

Question 3

the stability of the conjugate base depends on __-

Answer 3

how well it can accommodate a new pair of electrons

Question 4

carboxylate groups are stabilized by some degree of ___

Answer 4

resonance

Question 5

electron donating groups ___ the acidity

Answer 5

weaken

Question 6

electron withdrawing groups ___ the acidity

Answer 6

strengthen

Question 7

example of electron donating group

Answer 7

alkyl

Question 8

example of electron withdrawing group

Answer 8

chlorine

Question 9

what are the 6 key factors that influence acidity?

Answer 9

1. charge
2. electronegativity
3. size
4. inductive effect
5. orbitals
6. resonance

Question 10

acidity ___ with greater positive charge

Answer 10

increases

Question 11

acidity ___ with greater electronegativity

Answer 11

increases

Question 12

acidity __- with greater size atom

Answer 12

increases

Question 13

acidity ___ with greater resonance

Answer 13

increases

Question 14

acidity ___ with nearby electron withdrawing groups

Answer 14

increases

Question 15

acidity increases with more ___ orbital character

Answer 15

s

Question 16

what is the isoelectric point?

Answer 16

the pH at which the amino acid carries not net charge

Question 17

titration curves show the changing ___- state of an amino acid as the pH increases

Answer 17

ionic