Lecture 11 - Enzyme inhibition

Question 1

Many, but not all, enzyme inhibitors structurally resemble

Answer 1

the substrate

Question 2

Types of enzyme inhibitors

Answer 2

• Competitive
• Uncompetitive
• Noncompetitive
• Mixed

Question 3

In competitive inhibition, there is a decrease in enzymatic activity caused by

Answer 3

binding of a substrate analogue to the active (catalytic) site

Question 4

In competitive inhibition, the inhibitor competes with the ______ for the ______ on the enzyme

Answer 4

substrate; active site

Question 5

In competitive inhibition, Vmax is

Answer 5

unchanged

Question 6

In competitive inhibition, Km

Answer 6

increases

Question 7

Increasing substrate concentration can

Answer 7

overcome competitive inhibition

Question 8

Using the Lineweaver-Burk plot, in competitive inhibition, the y-intercept

Answer 8

does not change

Question 9

The Lineweaver-Burk plot contains parallel lines in

Answer 9

uncompetitive inhibition

Question 10

In uncompetitive inhibition, Vmax

Answer 10

decreases

Question 11

In uncompetitive inhibition, Km

Answer 11

decreases

Question 12

An uncompetitive inhibitor effects the ______ of the enzyme, but not the ______.

Answer 12

catalytic function; substrate binding

Question 13

Using the Lineweaver-Burk plot, in uncompetitive inhibition, the y-intercept

Answer 13

decreases

Question 14

Using the Lineweaver-Burk plot, in uncompetitive inhibition, the slope

Answer 14

stays the same

Question 15

In noncompetitive inhibition, the inhibitor binds to

Answer 15

a site other than the active site and distorts the active site to inhibit the reaction

Question 16

In noncompetitive inhibition, the inhibitor does not

Answer 16

interfere with substrate binding

Question 17

In noncompetitive inhibition, the value of Vmax

Answer 17

decreases

Question 18

In noncompetitive inhibition, the value of Km

Answer 18

remains constant

Question 19

Using the Lineweaver-Burk plot, in noncompetitive inhibition, the y-intercept

Answer 19

changes

Question 20

Using the Lineweaver-Burk plot, in noncompetitive inhibition, the slope

Answer 20

changes

Question 21

Using the Lineweaver-Burk plot, in noncompetitive inhibition, the x-intercept

Answer 21

stays the same

Question 22

In mixed inhibition, the inhibitor binds to

Answer 22

a site other than the active site, and distorts the active site to inhibit the reaction

Question 23

In mixed inhibition, the two Ki values are

Answer 23

not equal

Question 24

In noncompetitive inhibition, the two Ki values are

Answer 24

equal

Question 25

Using the Lineweaver-Burk plot, in mixed inhibition, the y-intercept

Answer 25

changes

Question 26

Using the Lineweaver-Burk plot, in mixed inhibition, the slope

Answer 26

changes

Question 27

What causes permanent inactivation in irreversible inhibition

Answer 27

covalent binding of an inhibitor to an enzyme

Question 28

Suicide substrates are molecules used to

Answer 28

bind to an enzyme irreversibly and inactivate it

Question 29

An example of a suicide inhibitor is

Answer 29

penicillin