Enzymes

Question 1

define the rxn: nucleophilic substitution

Answer 1

swapping of functional groups

Question 2

define the rxn: nucleophilic addition

Answer 2

addition of functional groups

Question 3

define the rxn: carbonyl condensation

Answer 3

change # of carbons

Question 4

define the rxn: elimination

Answer 4

change (increase) bond order

Question 5

define the rxn: oxidation-reduction

Answer 5

move electrons

Question 6

how do we know oxidation/reduction occurred in a redox rxn?

Answer 6

follow the e-s as it carries the H. OIL RIG

Question 7

oxidoreductases are what type of rxn?

Answer 7

oxidation-reduction

Question 8

transferases are what type of rxns?

Answer 8

group transfer

Question 9

hydrolases are what type of rxns?

Answer 9

hydrolysis rxns ie break a chem bond by adding h20

Question 10

lyases are what type of rxns?

Answer 10

Break a chem bond w/oo using h20

Question 11

isomerases are what type of rxns?

Answer 11

isomerization ie rearrange order of atoms in a molecule

Question 12

ligases are what types of rxns?

Answer 12

Use ATP to piece 2 pieces together ie make a chem bond

Question 13

what are the coenzymes fo oxidoreductases?

Answer 13

NADH, NADPH, FADH2, FMNH2

Question 14

what is the vitamin precursor for NADH and NADPH

Answer 14

B3 niacin (nicotinate)

Question 15

what group does the coenzymes for oxidoreductases carry?

Answer 15

electrons

Question 16

what is the vitamin precursor for FADH2 and FMNH2?

Answer 16

b2 (riboflavin)

Question 17

ribitol is a reduced form of _

Answer 17

ribose

Question 18

what is the enzyme for the coenzyme NAD?

Answer 18

lactate dehydrogenase

Question 19

what is the enzyme for the coenzyme flavin adenine nucleotide?

Answer 19

monoamine oxidase

Question 20

what are the coenzymes for trasnferase: transfer of a phosphate group?

Answer 20

ATP, pyridoxal phosphate

Question 21

the carrier molecule ATP (in its active form) carries what group?

Answer 21

phosphoryl

Question 22

what are the coenzymes for trasnferase: transfer of a methyl group?

Answer 22

SAM, tetrahydrofolate, and 5’deoxyadenosylcobalamin

Question 23

for the conezyme pyridoxal phoshate, what is the enzyme?

Answer 23

glycogen phasphorylase

Question 24

what is the vitamin precursor for tetrahydrofolate

Answer 24

Folate B9

Question 25

the group carried by tetrahydrofolate?

Answer 25

one-carbon units

Question 26

SAM is the primary _ donor in cells

Answer 26

methyl

Question 27

what is the enzyme for coenzyme tetrahydrofolate?

Answer 27

thymidylate synthase

Question 28

what is the enzyme for coenzyme 5'-deoxyadenosylcobalamin

Answer 28

methylmalonyl mutase

Question 29

hydrolases _ a chemical bond by _ h20 across it

Answer 29

break by adding h20

Question 30

isomerases _ order of atoms in a molecule

Answer 30

rearrange

Question 31

lyases _ a chem bond _ h20

Answer 31

break without h20

Question 32

ligases use _ to _ a chem bond

Answer 32

use ATP to make a chem bond

Question 33

what are the coenzymes with +/- aldehyde group?

Answer 33

TPP

Question 34

what is the vit precursor for TPP?

Answer 34

B1

Question 35

what is the enzyme for coenzyme TPP?

Answer 35

pyruvate dehydrogenase

Question 36

what are the conenzymes for +/- an acyl group?

Answer 36

CoAsh and lipoamide

Question 37

what is the vit precursor for CoAsh

Answer 37

B5 (pantothenate)

Question 38

what are the building blocks for lipoamide

Answer 38

a fatty acid derivative and lysine

Question 39

what is the enzyme for coenzyme A

Answer 39

acetyl CoA carboxylase

Question 40

for +/- CO2, what is the coenzyme?

Answer 40

biotin

Question 41

what is the vit precursor for biotin?

Answer 41

B7 biotin

Question 42

what is the conenzyme for coenzyme biotin

Answer 42

pyruvate carboxylase

Question 43

the active site is only a few residues out of the protein, t/f?

Answer 43

true

Question 44

the active site is 3D pocket creating a unique _

Answer 44

microenvironment

Question 45

the active site determines substrate specificity by __

Answer 45

size and charge complimentary

Question 46

the active site contacts with the substrate through __ interactions

Answer 46

non-covalent ie temporary

Question 47

a receptor just binding a __

Answer 47

just binding a protein (ligand)

Question 48

an enzyme-substrate not only binds to target substrate but also

Answer 48

does something with what we bind

Question 49

allosteric binding occurs where

Answer 49

does not occur at the active site

Question 50

allosteric binding involves a 2nd substrate which can be a _ or a _

Answer 50

activator of inhibitor

Question 51

how does an allosteric inhibitor fcn

Answer 51

inhibitor binds to allosteric site and changes protein active binding site so substrate no longer binds; build up of unbound substrate

Question 52

how does an competitive inhibitor fcn

Answer 52

inhibitor looks close enough to actual substrate and able to fit in the active binding site for it

Question 53

how does an allosteric activator fcn

Answer 53

conformational change of enzyme causes rxn to be halted bc of its incorrect shape. activator binds and changes to correct shape so substrate can bind and rxn can continue

Question 54

holoenzymes are whole and active and contain _

Answer 54

cofactor/coenzyme that are allosteric activators

Question 55

apoenzymes are incomplete and inactive and lack __

Answer 55

cofactor/conenzyme

Question 56

when Y =0

Answer 56

no ligand bound

Question 57

when Y =1

Answer 57

receptor is saturated

Question 58

when Y = 0.5

Answer 58

receptor is half saturated ; kD =[S]

Question 59

what is cooperativity

Answer 59

binding of each subsequent ligand influences the affinity of the next ligand to bind

Question 60

nH=1

Answer 60

no cooperativity (sites are independent)

Question 61

nH is greater than 1

Answer 61

positive cooperativity (affinity increases)

Question 62

nH is greater than 0 but less than 1

Answer 62

negative cooperativity (affinity decreases) ie next ligan is even more difficult to bind