Enzymes

Front 1

What do enzyme names often end in?

Back 1

-ase

Front 2

What is an isozyme? What is the same and what differs?

Back 2

Isoforms of enzymes--catalyze the same chemical reaction, but reaciton rates differ, often different tissue, etc.

Front 3

What are the 6 classes of enzymes?

Back 3

Oxidoreductase, transferase, hydrolase, lyase, isomerase, ligase

Front 4

What type of reactions deal with oxidoreductases? What are some enzyme names? What are some common co-enzymes?

Back 4

oxidation reduction
Coenzymes: NADH, NADPH, FADH2
Common enzyme names: dehydrogenase, peroxidase, reductase, oxidase, hydroxylase

Front 5

What kind of enzyme is cytochrome p450?

Back 5

oxidoreductase

Front 6

What do oxygenases do?

Back 6

Oxidoreductase-transfer both O2 atoms to substrate

Front 7

What happens in a transferase enzyme reaction?

Back 7

AB+C-->A+BC

Front 8

What does the enzyme name tell you with transferase enzymes? 2 answers

Back 8

Which chemical group is being transferred OR
Which chemical is being syntehsized

Front 9

Transfer an amine group is known as a _________; Transfers a phosphate group is __________; Indicates what kind of product is being formed is ______: These are all types of what kind of enzyme?

Back 9

Aminotransferase; kinase; synthase (i.e. glycogen synthase is synthesis of glycogen)

These are all transferases

Front 10

What do hydrolases do? What does X=? What is used to split a bond? What are some common names of hydrolases?

Back 10

They hydrolyze, duh. Involves water/alcohol.

X=O, N, or S

Water is used to split a bond

Common names: esterase, phosphatase, urease, protease

You probably also see hydrolases than any other enzyme

Front 11

What do lyases do (what kind of bond is involved)? When are they known as synthases? In what case do these deal with double bonds?

Back 11

They cleave covalent bonds by something other than hydrolysis or oxidation (the freaks go in here)

C-C, C-O, C-S, C-N

Known as synthases when reverse reactions are done to form bonds

Form C=C bonds by removing water from COH-CH

Front 12

What happens with isomerase reactions?

Back 12

No atoms are lost or added, only rearraged.

Front 13

Epimerase, racemase, and mutases are all examples of what kind of enzyme?

Back 13

Isomerases

Front 14

What is required with ligases to form covalent bonds? What side is this transferred to in the reaction? What can be substituted? What is the common name for ligases?

Back 14

ATP

GTP can be substituted or a similar nucleotide

The phosphate group is not transferred to EITHER SIDE (only the energy is used)

the common name is synTHEtase (not synthase,foo)

Front 15

Metal ions can serve two different functions as ligands...

Back 15

Enzymatic (co-factors) or structural ligands

Front 16

The iron in the heme group in hemoglobin and the cytochromC isozymes are examples of how petal ions can act as part of ____________

Back 16

Prosthetic groups

Front 17

Vitamins can act as _____ or ______

Back 17

enzyme cofactos or coenzymes

Front 18

Without the co-factor, can the respective chemical reaction occur?

Back 18

Nope

Front 19

Hydroxylase a hydrolase? Is synthetase a transferase?

Back 19

No, hydroxylase is an oxidoreductase. Synthetase is a ligase (synthase is a transferase)

Front 20

State the group carried with the following carrier molecules: ATP (ADP/Pi, AMP/PPi), NADH/NAD+, NADPH/NADP+, FADH2/FAD (FMNH2/FMN)

Back 20

ATP: phosphoryl groups -PO3-2, very high energy bond stores chemical energy, protein phosphorylation

NADH: shuttle electrons for redox of biological fuels, helps produce ATP

NADPH: Shuttle electrons for redox of bioSYNTHESIS reactions

FADH2: Shuttle electrons for redox of biological fuels, more powerful than NAD's, always bound to a protein

Front 21

Which is more powerful, FADH2 or NADH (which has stronger redox capabilities)?

Back 21

FADH2

Front 22

Which carrier molecule is ALWAYS bound to a protein?

Back 22

FADH2,FMNH2

Front 23

Can you recognize NAD? Is it small?

Back 23

I hope so. Look it up, be able to notice that enzymes can detect the difference in hydroxyl and phosphoryl groups, would take a large active site to bind to that molecule

Front 24

Which is a stronger oxidizing agent, NAD+ or flavins?

Back 24

Flava flav...ins

Front 25

Which of the carriers is seen as a "prosthetic group" because it binds so tightly?

Back 25

FAD/flavins

Front 26

What in the flavin ring is the active site that is oxidized/reduced?

Back 26

N-C-C-N in the ring structure of the flavin (see notes)

Front 27

Name the group carried with the following carrier molecules: coenzyme A, thiamine pyrophosphate, biotin, tetrahydrofolate amino acid metabolism, s-adenosylmethionine

Back 27

Coenzyme A: acyl groups (o=C-r) where R is CH3 and longer ::A is for acyl

Thiamine: Aldehydes (decarboxylation) =O-c-H

Biotin: (carboxylation) CO2

Tetrahydrofolate: 1 carbon unit -CH3, =CH2, -COO- to carbon or sulfur

S-adenosylmethionine: methyl to oxygen or nitrogen

Front 28

Catalytic enzyme in chymotrypsin is a hydrolase::what is it, and what participant is expected in it?

Back 28

Protease, water

Front 29

With chymotrypsin, what is the two part reaction series? What is liberated, what is attached?

Back 29

An acyl enzyme is formed with a covalent intermediate attached to the chymotrypsin (the substrate is similar to a peptide bond in a protein in that it is o-c=o as opposed to n-c=o

The acetyl enzyme then reacts with water (hydrolysis) to form chymotrypsin-oh

Front 30

In the tetrahedral state of the partial bonds of asp his and serine in the acyl intermediate, What bond is broken? What pull causes the oxygen in serine to be more electronegative? Which aa is attached to the substrate?

Back 30

The O-H bond in serine is broken, and serine is attached to the substrate. This is a result of the partial charge pull of the O-H bond between Asp and His

Front 31

The chymotrypsin catalysis reaction demonstrates what two things regarding side chains?

Back 31

-Charged side chains substitute for harsh inorganic acids and bases

-Side chains temporarily form covalent interactions with substrate

Front 32

List some of the things active sites contribute

Back 32

Besides energy, encounter, and orientation....

"strain" the reactant to look more liek the transition state or product

bind more tightly to the TRANSITIONSTATE than to reactants or products (lower energy)

Trap two reactants close to each other

Orient two reactants, so that the proper regions are juxtaposed

Front 33

Racemases and epimerases are what kind of enzyme?

Back 33

Isomerases

Front 34

Proteases are what kind of enzyme?

Back 34

Hydrolases

Front 35

Proteases are classified based on what?

Back 35

the ACTIVE SITE of the protease

Front 36

What are the four proteases that we classified?

Back 36

serine proteases, metalloproteases, aspartic proteases, serine proteases

Front 37

Papain, calpain, and interleukin 1-b are all types of what kind of proteases?

Back 37

Cysteine proteases

Front 38

When are cysteine proteases inhibited? What type of chemical covalently does this?

Back 38

When the cysteine is modified

Chemical that interacts with a sulfhydryl

Front 39

What pH are aspartic proteases active? What are some examples? Which other amino acid has a similar side chain chemistry?

Back 39

Low pH
Pepsin, rennin, HIV protease
Glutamic acid

Front 40

Pepstatin inhibits what aspartic protease by mimicing protein substrate?

Back 40

Rennin

Front 41

Are human aspartic proteases usually monomeric or dimeric? How about the HIV protease? How does this help in drug design?

Back 41

Monomeric
HIV protease: dimeric
Design drugs that bind only to dimeric

Front 42

Why are "cocktail" drugs made for treatment of HIV

Back 42

Mutations in HIV in spots in other than the aspartic are possible (drug resistance), so by making ~8other drugs that act by similar mechanisms, and it's unlikely one mutation can knock out all 8 mutations at once, and even if it did it probably knocked out the substrate as well, resulting in a dead enzyme regardless

Front 43

Metalloproteases: what is required in the active site? What are some examples, and what are some examples of metalloproteases? What is it inhibited by?

Back 43

Metal ion are required
Usually Zn2+, sometimes Co2+, may require Ca2+ for structure
Carboxypeptidase, thermolysin, collagenase, matrix metalloproteases (MMPs)

Inhibited by EDTA

Front 44

What catalytic triad is required in serine proteases? What inhibits serine proteases? What aa can substitute in the triad?

Back 44

Conserved Asp, Ser, His (chymotrypsin)
DFP inhibits (diisopropylflurorophosphate), as well as serpins

Threonine (OH like serine)

Front 45

What type of protease is thrombin and enteropeptidase?

Back 45

Serine proteases

Front 46

What protease is a substitute serine protease that is also a sucessful cancer drug design?

Back 46

Threonine protease (asp, thr, his)

Front 47

Protease specificity: are proteases specific in their cleaving? how is this related to the AA that is being cleaved?

Back 47

Yes, each protease recognizes a different amino acid sequence; however, it is unrelated to the aa that it is specifically cleaved between