Enzyme inhibitors

Question 1

How does allopurinol bind

Answer 1

Non covalently
Binds to serine on xanthine oxidase which mimics hypoxanthine

Question 2

What does allopurinol prevent

Answer 2

Production of uric acid

Question 3

Aspirin

Answer 3

irreversible, covalent inhibitor
Binds covalently to serine of COX and inhibits production of prostaglandins which cause pain and swelling

Question 4

How do organophosphates bind

Answer 4

Covalently

Question 5

What does organophosphates do

Answer 5

Irreversible covalent inhibitor
Binds to sarin nerve gas and pesticides
Binds to serinde residue on acetylcholinesterase
-can’t break down Ach and causes paralysis

Question 6

What kind of inhibitor is allopurinol

Answer 6

Suicide

Question 7

What kind of enzyme is penicillin

Answer 7

Suicide, transition state analog

Question 8

What does penicillin inhibit

Answer 8

glycopeptide aminotransferase

Question 9

What does penicillin do

Answer 9

Suicide inhibitor
Pretends to be glycopeptide transpeptidase which cleaves bacterial cell wall
Active site serine attacks it and gets stuck

Question 10

How many carbons does stearic acid have

Answer 10

18 (s)

Question 11

How many carbons in palmitic acid

Answer 11

16 (p)

Question 12

Saturated fats are _____ at room temperature

Answer 12

Solid

Question 13

Which glycerophospholipids is predominantly found on the outer leaflet of the plasma membrane

Answer 13

Phosphatidylcholine

Question 14

General acid/base catalysts

Answer 14

Glu, His, Asp
Conditional: Lys, Ser, Tyr, Cys, Arg

Question 15

Covalent catalysts

Answer 15

His, Lys, Ser, Cys

Question 16

What type of inhibitor is statin

Answer 16

Competitive inhibitor
Treats hypercholesterolemia

Question 17

V0 is limited by

Answer 17

K3

Question 18

Km equation

Answer 18

K2+k3/K1

Question 19

What is “on”

Answer 19

K1

Question 20

What is “off”

Answer 20

K2+K3

Question 21

how to find Km based on michaelis menton graph

Answer 21

Take 1/2 of vmax

Question 22

[s] <km

Answer 22

vmax/km

Question 23

[S]»km

Answer 23

vmax

Question 24

Hexokinase I

Answer 24

Present in RBC
works at vmax so that RBC always has energy

Question 25

Glucokinase

Answer 25

Present in hepatocytes Rate depends on serum glucose

Question 26

What happens to glucokinase in fed state

Answer 26

Increases

Question 27

What happens to glucokinase in fasted state

Answer 27

decreases

Question 28

X intercept of LWB

Answer 28

-1/km

Question 29

Slope of LWB

Answer 29

Km/vmax

Question 30

Y intercept of LWB

Answer 30

1/vmax

Question 31

What does an x-intercept close to 0 mean on LWB

Answer 31

Higher Km

Question 32

What does a high y-intercept on LWB mean

Answer 32

Lower vmax

Question 33

LWB equation

Answer 33

1/v0=km/vmax(1/[S]) + 1/vmax

Question 34

Irreversible inhibitors

Answer 34

Bind extremely tightly to enzyme or form covalent bond

Question 35

Competitive inhibition can be reversed by

Answer 35

Increasing substrate concentration

Question 36

What is the only thing that can increase vmax

Answer 36

Adding enzyme

Question 37

Why does Km decrease in uncompetitive inhibibition

Answer 37

Equilibrium shifts right to get rid of ES

Question 38

In vitro

Answer 38

in parts IC50

Question 39

In vivo

Answer 39

whole tissue EC50

Question 40

Low IC50 or EC50 means

Answer 40

more potent, less of the drug is required to be effective

Question 41

What are the covalent inhibitors

Answer 41

Aspirin, Organophosphates

Question 42

What are the suicide inhibitors

Answer 42

Penicillin, Allopurinol