Chapter 8- Enzymes

Question 1

Life can be defined as what?

Answer 1

• dynamic
• coordinated network of chemical reactions
• avoiding equilibrium

Question 2

How do we coordinate chemical reactions? And why are they usually not coordinated?

Answer 2

• we want them coordinated which is done by enzymes
• they can’t because they have different kinetics

Question 3

what brings about coordination in individual reactions?

Answer 3

catalysis and the catalysts are enzymes

Question 4

How are enzymes catalysts?

Answer 4

adjust there RATE of every reaction

Question 5

Do the rates of catalysis differ? And why is this important?

Answer 5

Yes, completely. From seconds to billions of years. This refers to the reason of coordination and how it becomes completely coherent.

Question 6

How do catalysts work?

Answer 6

1. decrease activation energy (Ea)
2. change kinetics but not the thermodynamics of a reaction

Question 7

What do catalysts take time?

Answer 7

transition state

Question 8

If DELTA G is positive what can be said about the the reaction? And what about if DELTA G is negative?

Answer 8

-: favorable
+: not favorable

Question 9

If DELTA G is at 0 what can be said about the reaction?

Answer 9

at equilibrium

Question 10

Enzymes have two part active site that accomplishes what?

Answer 10

substrate binding and catalysis

Question 11

What are the two things that enzymes do?

Answer 11

1. bind substrate (enzyme- substrate complex)
2. change substrate into product and dissociate

Question 12

What do enzymes have in relation to there substrates?

Answer 12

specificity (unique and wide open)

Question 13

Substrate binding is usually what kind of model? What is the other model that it sometimes can be?

Answer 13

1. induced fit
2. lock and key

Question 14

Enzymes are classified how?

Answer 14

proteins

Question 15

Michaelis Menten kinetics characterizes a majority of enzymes quantifying what?

Answer 15

1. substrate affinity (KM)
2. catalysis (V-max)

Question 16

For the Michaelis Menten curve what is the x axis and what is the y axis?

Answer 16

x: substate concentration
y: reaction velocity

Question 17

For a simple saturated curve what can be explained about it?

Answer 17

it asymptotically reaches max velocity

Question 18

The rate for enzymes in MM is dependent on what?

Answer 18

concentration

Question 19

How many experiments do you have to do for enzyme kinetics?

Answer 19

multiple more than 4

Question 20

What is the slope in Enzyme kinetics?

Answer 20

velocity

Question 21

Why does the enzyme go at different rates?

Answer 21

concentration varies of 1 substrate

Question 22

Why is MM kinetics important?

Answer 22

Help understand how enzymes work

Question 23

What is KM?

Answer 23

substrate concentration yielding a velocity of Vmax/2
The KM value for an enzyme depends on the particular substrate and on environmental conditions such as pH, temperature,
and ionic strength.

Question 24

What does the KM value depend on?

Answer 24

1. on the particular substrate
2. on environmental conditions
3. pH
4. temperature
5. ionic strength

Question 25

Big VMAX is.....

Answer 25

high rate at better which it catalyzes

Question 26

Big KM is....

Answer 26

worse substrate affinity

Question 27

Enzymes that have what have non MM kinetics?

Answer 27

cooperativity

Question 28

Sigmodial curve means

Answer 28

cooperative enzyme and Non MM kinetics

Question 29

Standard inhibition means what?

Answer 29

MM behaving

Question 30

What are some types of standard inhibition?

Answer 30

competitive, non competitive, and uncompetitive

Question 31

What can regulate enzymes?

Answer 31

Standard inhibition or MM behaving

Question 32

What is a non competitive inhibitor?

Answer 32

affects the substrates ability to catalyze but not to bind

Question 33

What is an uncompetitive inhibitor?

Answer 33

affects both the binding and catalysis

Question 34

In competitive inhibition what is to be said about KM and Vmax?

Answer 34

KM change Vmax same

Question 35

In non competitive inhibition what is to be said about KM and Vmax?

Answer 35

Vmax change KM same

Question 36

In uncompetitive inhibition what is to be said about KM and Vmax?

Answer 36

Vmax change KM change

Question 37

What makes good competitive inhibitors?

Answer 37

transition state analogs

Question 38

How do enzymes work?

Answer 38

decrease activation energy make the transition state with lower energy

Question 39

Can you make a transition state? If so why not?

Answer 39

You cannot make a transition because unless an analog (or similar compound) is used

Question 40

When is standard inhibition most commonly used in a pharmacology application?

Answer 40

Penicillin

Question 41

Enzymes can use what and can be classified how?

Answer 41

cofactors coenzymes cosubstrates can be classified by the type of reaction they catalyze