Chapter 3

Question 1

in many what, His serves as a what

Answer 1

enzyme-catalyzed reactions, serves as a proton acceptor/donor

Question 2

Aspartate and Glutamate carry a what and have what in their side chains

Answer 2

-net charge of -1 and have carboxyl groups in their side chains

Question 3

Glutamate is responsible for what

Answer 3

one of the five basic tastes

Question 4

Amino acids what in aqueous solutions and are what

Answer 4

ionize and are amphoteric (can act as both weak acids and bases)

Question 5

the dipolar ion of an amino acid is called a

Answer 5

zwitterion

Question 6

The tripotic amino acids include (7)

Answer 6

Lys, Arg, His, Asp, Glu, Cys, Tyr

Question 7

what is the isoelectric point

Answer 7

is the pH at which the net charge of a molecule is equal to zero

Question 8

For a pH below the pKa

Answer 8

the protonated form predominates HA

Question 9

For a pH above the pKa,

Answer 9

the unprotonated form predominates A-

Question 10

at pH 7.4 the groups carboxyl and amino will be

Answer 10

in the COO- and NH3+ forms