Enzyme Categories

Question 1

6 classes of enzymes

Answer 1

1. oxidoreductases
2. transferase
3. hydrolase
4. lyase
5. isomerase
6. ligase

Question 2

oxidoreductase formula

Answer 2

Aox+Bred–> Ared + B ox

Question 3

oxidoreductase common co-enzymes

Answer 3

NADH, NADPH, FADH2

Question 4

oxidoreductase common enzyme names

Answer 4

1. dehydrogenase
2. peroxidase
3. reductase

Question 5

oxidoreductase special names

Answer 5

1. oxidase or hydroxylase
   * transfer O2 atoms to water or to substrate and water
2. cytochrome p450
3. oxygenases: transfer both O2 atoms to substrate

Question 6

transferase formula

Answer 6

AB + C –> A + BC

Question 7

transferase enzyme name meaning

Answer 7

the name is the chemical group that is transferred or what chemical is synthesized

Question 8

transferase special names

Answer 8

1. aminotransferases–> transfer an amine group
2. kinase–> transfer a phosphate group
3. synthase–> indicates what kind of product is formed (glycogen synthase)

Question 9

hydrolase formula

Answer 9

CX+ H20 –> C-H + X-OH
where X= O, N, or S
**all split bonds by splitting water

Question 10

hydrolase special names

Answer 10

1. protease
2. esterase
3. phosphatase
4. peptidase
5. urease

Question 11

what do lyases do?

Answer 11

the “catch all:”

1. cleave C-C, C-O, C-S, and C-N bonds by means other than oxidation or hydrolysis
2. form C=C bonds by removing H2O from COH-CH

Question 12

lyase example common names

Answer 12

1. decarboxylase

2. aldolase

Question 13

lyase reverse reaction to form bonds

Answer 13

synthases

Question 14

what do isomerases do

Answer 14

no atoms lost or added, only rearranged

Question 15

common isomerase names

Answer 15

1. epimerase
2. racemase
3. mutase

Question 16

ligase formula

Answer 16

A + B + ATP–> AB + ADP + Pi

Question 17

what do ligases do?

Answer 17

form C-C, C-S, C-O, and C-N bonds

*require ATP or another nucleotide

Question 18

ligase common name

Answer 18

synthetase

Question 19

cofactors

Answer 19

cofactors often derived from vitamins, metal ions can also serve as catalystic co-factors

Question 20

group carried by ATP, ADP/Pi, and AMP/PPi

Answer 20

1. phosphoryl groups
2. very high energy bond stores chemical energy
3. protein phosphorylation

Question 21

group carried by NADH/NAD+

Answer 21

• shuttle electrons for redox of biological fuels

- -> help produce ATP

Question 22

group carried by NADPH/NADP+

Answer 22

-shuttle electrons for oxidation in biosynthesis reactions

Question 23

groups carried by FADH2/FAD or FMNH2/FMN

Answer 23

• shuttle electrons for redox of biological fuels
• more powerful than NAD
• always bound to a protein

Question 24

coenzyme A is a carrier molecule for…

Answer 24

acyl groups

R=CH3 and longer

Question 25

biotin is a carrier molecule for...

Answer 25

CO2 | carboxylation

Question 26

tetrahydrofolate amino acid metabolism is a carrier for...

Answer 26

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

Question 27

S-adenosylmethionine is a carrier molecule for...

Answer 27

methyl to oxygen or nitrogen

Question 28

pyridoxal phosphate reaction with...to catalyze....

Answer 28

amines, NH2 =NH to catalyze amino acid metabolism, transamination reactions

Question 29

thiamine pyrophosphate reacts with...to catalyze...

Answer 29

aldhydes/ketones to form decarboxylation at the R group

Question 30

4 classes or proteases

Answer 30

1. cysteine proteases 2. aspartic proteases 3. metalloproteases 4. serine proteases

Question 31

cysteine proteases active site

Answer 31

cysteine

Question 32

cysteine proteases examples

Answer 32

1. papain (meat tenderizer) | 2. cathepsin B (lysosome)

Question 33

aspartic proteases active site

Answer 33

aspartate | **active at low pH

Question 34

aspartic protease examples

Answer 34

1. pepsin | 2. HIV protease

Question 35

metalloprotease active site requirement

Answer 35

- metal ion usually Zn2+ | - sometimes CO2+

Question 36

metalloprotease examples

Answer 36

1. collagenase | 2. matrix metalloproteases (MMPS)

Question 37

serine protease active site

Answer 37

catalytic triad: asp, ser, his

Question 38

serine protease examples

Answer 38

1. trypsin, chymotrysin 2. elastase (connective tissue) 3. thrombin (blood clotting)

Question 39

serine proteases are inhibited by

Answer 39

serpins | ex: alpha-1-antitrypsin

Question 40

how do serpins inhibit proteases

Answer 40

1. normal catalysis involves temporary covalent attachment between protease and substrate 2. serpin mimics the normal subsrate 3. serpin binds covalently and then changes conformation to inactive the serine protease

Question 41

serpin is a suicide inhibitor

Answer 41

meaning that one serpin per one enzyme | ** can counteract irreversibly active proteases

Question 42

anti-thrombin

Answer 42

-inhibits coagulation in blood clotting cascade

Question 43

alpha-1-anti-trypsin

Answer 43

- inhibits neutrophil elastase in lungs (protective) - inactivated by cigarette smoke - low levels pre-dispose towards emphysema nd cirrhosis

Question 44

prepro-enzyme

Answer 44

inactive enzyme as translated from mRNA that has a leader sequence for location

Question 45

pro-enzyme (zymogen)

Answer 45

in the right location and leader sequence cleaved but is inactive

Question 46

mature protease

Answer 46

other region of the protease cleaved and is active

Question 47

metal ions can have two seperate roles

Answer 47

1. cofactors | 2. structural ligands

Question 48

structural ligands

Answer 48

can help protein stay folded

Question 49

catalystic ion

Answer 49

in the active site participates in the chemistry