enzymes

Question 1

enzymes are ____ catalysts

Answer 1

biological

Question 2

biological catalysts have milder reactions compared to chemical catalysts and have greation reaction _____ with respect to substrates and products (have capacity for regulation)

Answer 2

specificity

Question 3

why is it important that proteins and enzymes are regulated

Answer 3

to stay away from disease state but also to facilitate interactions (can change structure or use cofactors, remove things physically, storage or phosphorylation)

Question 4

enzymes ____ reaction rates compared to uncatalyzed reactions and chemically catalyzed reactions n

Answer 4

increase

Question 5

enzymes use _____ conditions comared to chemical catalysis

Answer 5

milder

Question 6

nitrogen fixation can be catalyzed by

Answer 6

1. lightning
2. haber process (150-250 atmospheres)
3. symbiotic bacteria in root nodules of legumes

Question 7

enzymes have reaction specificity as well as _____ specificity and ____

Answer 7

geometry (of chemical structures) & stereo

Question 8

the regulation of the activity of an enzyme by binding of an inhibitor or activator at a site on the protein separate from the substrate binding site

Answer 8

allostery

Question 9

regulation: phosphorylation, acetylation, and removal of inhibitory peptides

Answer 9

covalent modification

Question 10

regulation of enzymes: assembly into ____ complexes

Answer 10

macromolecule

Question 11

regulation of metabolic pathway by the inhibition of enzyme that catalyzes a reaction early in the pathway by the product of the pathway

Answer 11

feedback inhibition

Question 12

the ____ is missing a cofactor or co enzyme

Answer 12

apoenzyme

Question 13

when a ____ contains a cofactor or coenzyme and can act on substrate

Answer 13

haloenzyme

Question 14

common names of enzymes end in

Answer 14

ase

Question 14

some enzymes need help to catalyze their reactions so they use a ____

Answer 14

cofactor

Question 14

co factors can be

Answer 14

small molecules or metal ions

Question 15

organic cofactors derived from vitamins, may associate transiently or be tightly linked

Answer 15

coenzymes

Question 16

delta G double dagger is

Answer 16

activation energy barrier

Question 16

the standard free energy change from product to substrate is

Answer 16

standard free energy change

Question 17

delta G’° is how ___ that the reaction will happen

Answer 17

likely

Question 18

delta G double dagger is how ___the reaction will take place

Answer 18

fast

Question 19

enzymes can only change which delta G

Answer 19

delta G double dagger

Question 20

a large delta G double (large activation barrier) dagger means ___ k and ___ reaction

Answer 20

small (rate constant) , slow

Question 21

delta G’° < 0 has more ___ than __ at equilibrium (forward rxn is favorable)

Answer 21

P S

Question 22

if delta G double dagger is big enough it will never reach equilibrium no matter how ____ delta G’°

Answer 22

negative

Question 23

enzymes low ___

Answer 23

deltaG double dagger

Question 24

ES and EP can be considered __ ___

Answer 24

reaction intermediates

Question 25

the step with the highest energy barrier is (has smallest k)

Answer 25

rate limiting step

Question 26

enzymes catalyze both forward and ___ reactions

Answer 26

reverse

Question 27

what is a catalyzed reaction step wise

Answer 27

S+E <—> ES <—-> EP <—> P + E

Question 28

an enzymes active site should be complimentary to the _____ state to break up products

Answer 28

transition

Question 29

if the enzyme is complimentary to substrate it will stabilize ___ state which increases the delta G double dagger significantly

Answer 29

ES

Question 30

catalytic power of enzymes derived from

Answer 30

1. binding energy
2. binding is optimized to the transition state

Question 31

conversion from two free reactants to one single transition state is entropically _____

Answer 31

unfavorable

Question 32

uncatalyzed unimolecular reactions has a flexible reactant —> rigid transition state; the conversion is entropically _______

Answer 32

unfavorable

Question 33

enzymes uses the binding energy of substrates to organize reactants to fairly rigid ES complex; when is entropy cost paid

Answer 33

during binding

Question 34

interactions between S and H2O are replaced by S and E; increases reaction rate

Answer 34

desolvation of substrates

Question 35

catalysis involves formation of ____ bonds

Answer 35

covalent

Question 36

specific acid base catalysis means that donation/ abstraction of charge is carried out by _____

Answer 36

water

Question 37

occurs frequently with general acid base catalysis and results in new reaction pathway that are uncatalyzed

Answer 37

covalent catalysis

Question 38

as long as the steps involved in forming and breaking the covalent bonds are ____ than the uncatalyzed, catalysis will occur

Answer 38

faster