Enzyme Kinetics

Question 1

____ are protein that increase the rate of biochemical reactions

Answer 1

enzymes

Question 2

Reactions could not occur without ____

Answer 2

enzymes

Question 3

Enzymes make up ____ _____ such as ones that synthesize new molecules and generate cellular energy

Answer 3

metabolic pathways

Question 4

what are the 3 main distinctive features of enzymes?

Answer 4

catalytic power, specificity, regulation

Question 5

increasing the rate of biochemical reactions is what power of enzymes?

Answer 5

catalytic power

Question 6

Selectively acting upon a substrate to carry out a particular reaction is what power of enzymes?

Answer 6

specificity

Question 7

there are ______ of enzymes encoded in the human genome

Answer 7

1,000s

Question 8

the ____ is the initial molecule in a reaction

Answer 8

substrate

Question 9

Enzyme activity being regulated by a variety of mechanisms is what power of enzymes?

Answer 9

regulation

Question 10

Enzymes ______ the free energy of activation of biochemical reactions

Answer 10

decrease

Question 11

Enzymes ____ the rate of reactions

Answer 11

increase

Question 12

Less ______ ___ _____ is needed for a reaction to occur when the temperature is high

Answer 12

gibbs free energy (activation energy)

Question 13

The transition state is ______ for different temperatures

Answer 13

the same

Question 14

At higher temps, ______ reactant molecules can be converted to products

Answer 14

more

Question 15

more species cannot use temp to allow for reactions to occur because cells are _____ ______

Answer 15

temperature sensitive

Question 16

How many categories of enzymes are there?

Answer 16

6

Question 17

enzymes are _____ protein chains

Answer 17

globular

Question 18

enzymes are classified based on their _______

Answer 18

activity

Question 19

____ are enzymes that transfer electrons from one molecule to another

Answer 19

oxidoreductases

Question 20

______ are enzymes that transfer chemical groups

Answer 20

transferases

Question 21

Kinsases are a subgroup of what enzyme classification?

Answer 21

transferase

Question 22

_____ add a phosphate group to proteins, carbs, lipids, and nucleic acids

Answer 22

kinases

Question 23

_____ are enzymes that break covalent bonds by hydrolysis

Answer 23

hydrolases

Question 24

proteases are a subgroup of what enzyme classification?

Answer 24

hydrolases

Question 25

______ break down dietary protein by breaking peptide bonds

Answer 25

proteases

Question 26

______ are enzymes that cleave various bonds or add groups to double bonds

Answer 26

lyases

Question 27

_____ are enzymes that produce isomers

Answer 27

isomerases

Question 28

_____ enzymes use up a water molecule each time they break a bond and add the H+ and OH- groups to the broken bond end

Answer 28

hydrolases

Question 29

_____ are enzymes that join large molecules by forming covalent bonds

Answer 29

ligases

Question 30

____ are enzymes used in DNA cloning to covalently link backbone strands of different DNA molecules to form intact strands

Answer 30

ligases

Question 31

Do all enzymes need cofactors and coenzymes?

Answer 31

no

Question 32

Cofactors or coenzymes are ___ or ___ _____ linked

Answer 32

covalently, non-covalently

Question 33

_____ are metal ions or organic molecules that bind to enzymes and are required for enzyme activity

Answer 33

cofactors

Question 34

heme, flavin, and c based molecules are examples of _____

Answer 34

cofactors

Question 35

Coenzymes are a sub group of _____

Answer 35

cofactors

Question 36

_____ are b vitamin organic molecule derivatives that act as enzyme cofactors

Answer 36

coenzymes

Question 37

____ groups are tightly bound cofactors or coenzymes

Answer 37

prosthetic

Question 38

______ are catalytically active complexes of protein and coenzyme

Answer 38

holoenzyme

Question 39

____ are protein without the prosthetic group, and are not functional where a coenzyme is needed

Answer 39

apoenzyme

Question 40

Velocity of reaction is another term for what?

Answer 40

rate of reaction

Question 41

Velocity of reaction/rate of reaction is what?

Answer 41

amount of product formed or the amount of substrate consumed per unit time

Question 42

v=k[A] is the equation for what?

Answer 42

first order reaction

Question 43

In a ___ ____ _____, there is a directly proportionate relationship between substrate concentration and the amount of produce produced per unit time

Answer 43

first order relationship

Question 44

v=k[A][B] is the equation for what?

Answer 44

second order reaction

Question 45

In a second order reaction, _____ molecules reaction to form ____ products

Answer 45

2,2

Question 46

What equation is used for the kinetics of enzyme catalyzed reactions?

Answer 46

Michaelis-Menton Equation

Question 47

The M/M equation gives the rate of an enzyme reaction (v) in terms of what?

Answer 47

substrate concentration

Question 48

What are the two constants in the M/M equation?

Answer 48

Vmax, Km

Question 49

When substrate concentration is high, v= ____

Answer 49

Vmax

Question 50

When substrate concentration is high, v is not longer dependent on what?

Answer 50

substrate concentration

Question 51

When substrate concentration is high, the reaction is following what order kinetics?

Answer 51

zero

Question 52

When substrate concentration is low, this is what order reaction?

Answer 52

first

Question 53

v=(vmax/Km)*[S] is the equation when the substrate concentration is _____

Answer 53

low

Question 54

What variables are fixed in the M/M equation?

Answer 54

temperature, pH, and ionic strength

Question 55

___ ____ is the total concentration of the small ions

Answer 55

ionic strength

Question 56

What is the shape of the curve of the M/M equation data?

Answer 56

hyperbolic curve

Question 57

A ___ _____ is a curve that approaches but never reaches the max value

Answer 57

hyperbolic curve

Question 58

v= ____/______

Answer 58

product produced/unit time

Question 59

At Vmax/2, what is equal to what?

Answer 59

substrate, enzyme

Question 60

Km is a measure of what?

Answer 60

amount of substrate/unit volume

Question 61

Kcat is the value for what?

Answer 61

catalytic constant/turnover number

Question 62

Kcat measures the _____ amount of product produced per second when the enzyme is ____ with substrate

Answer 62

maximum, saturated

Question 63

What is the pH that most enzymes have peak activity?

Answer 63

7.4

Question 64

Kcat must be determined and compared under what type of conditions?

Answer 64

the same

Question 65

Kcat is similar to what other value?

Answer 65

Vmax

Question 66

What temp do most enzymes peak activity at?

Answer 66

40C

Question 67

kcat depends on what two things?

Answer 67

enzyme nature/efficiency, size/complexity of substrate

Question 68

Staphylococcal nuclease has a _____ kcat

Answer 68

low (95)

Question 69

Carbonic anhydrase has a ____ kcat

Answer 69

high (1,000,000)

Question 70

What does enzyme staphylococcal nuclease do?

Answer 70

attack DNA,RNA, and other molecules

Question 71

Why does carbonic anhydrase have such a high kcat?

Answer 71

CO2 and H2O are simple and small molecules

Question 72

There is no activity at too low or too high of a pH because of the interactions of what part of the amino acid?

Answer 72

positively or negatively charged side chains

Question 73

_____in an enzyme that breaks down food in the stomach, and is therefore at peak activity at a low pH of 1.5

Answer 73

pepsin

Question 74

_____ in an enzyme that breaks down food in the intestines' and has peak activity at pH 7.7

Answer 74

trypsin

Question 75

What in the stomach makes it acidic?

Answer 75

HCl

Question 76

At low temps, enzyme activity is ____ due to lack of energy

Answer 76

slowed

Question 77

At high temps, enzymes might undergo irreversible ______

Answer 77

denaturing (unfolding)

Question 78

denaturing of enzymes causes lack of ____

Answer 78

activity