Esterases: a hydrolase that hydrolyzes an ester into its components: an alcohol & an acid.


Acetycholine esterase [nerve gas blocks]

Phosphodiesterase 93,104,

Cholesterol esterase 30


Lipases: a hydrolase that catalyzes the breakup of ester linkages between a fatty acid & glycerol, w/I triglycerides & phospholipids


Serum Lipoprotein Lipase 31

Colipase 30

Gastric Lipase

Pancreatic Lipase [pancreatitis]

Phospholipase A

Lipoprotein lipase 117,118,120, 140,148 [stimulated by insulin]

Hormone Sensitive Lipase 119,142 [inhibited by insulin]

Nonspecific lipases 119


Nucleosidases: a hydrolase that breaks nucleosides into a purine or pyrimidine & ribose


Nucleotidases: a hydrolase that breaks down nucleotides to nucleosides & phosphoric acid


Peptidases: a hydrolase that facilitates the hydrolysis of a peptide bond.


Endopeptidases (pepsin, trypsin, chymotrypsin) 62

Exopeptidases (aminopeptidase, carboxypeptidase, dipeptidase) 62


Phosphatases: a hydrolase that hydrolyzes esters, releasing inorganic phosphate


Phosphatase 36

PDH phosphatase 27

Diphosphoglycerate phosphatase 58

FBPase 1 & 2 (Fructose 1,6-bisphosphatase) 81,87-88,111-113, 142

Glucose 6-Phosphatase 86,87,88,105 [Von Gierke’s Disease]

PK protein phosphatase 90,93,100-104,112-114, 119

Inorganic pyrophosphatase 98

Protein phosphatase 2A 115

Phosphatidic acid phosphatase 116


Sulfatases: a hydrolase that hydrolyzes molecules releasing sulfate


ISOMERASES: CATALYZES FORMATION OF ONE ISOMER FROM ANOTHER (e.g., an aldehyde to a ketone form, or moving a double bond from one site to another on a molecule)

Enoyl-CoA isomerase 35-36

Pentose phosphate isomerase 53,116

Glucose 6-P isomerase 42,45

Triosephosphate isomerase 42,45

Isomerase/Hydrolase 74


Epimerases: an isomerase that interconverts epimers

Pentose phosphate epimerase 53,116


Mutases (some):  a transferase or isomerase that shifts one group (e.g., acyl, amino, phospho, etc.) from one point to another on the molecule.


D-methylmalonyl CoA mutase 37

L-methylmalonyl CoA mutase (Req. Vit B12) 37, 72

Vitamin B12-dependent mutase 72

            *IF (intrinsic factor)

Phosphoglyceromutase 42,45

Phosphoglucomutase 50,97,105

Superoxide dismutase 56

Diphosphoglyceromutase 58




Racemases: an isomerase that catalyzes the change of an optically active molecule to its opposite mirror image form. 72




Carboxylases: a ligase that catalyzes the addition of CO2.  USUALLY REQUIRE BIOTIN! [absorption blocked by avidin]


PC (pyruvate carboxylase) 25,28,81,82,87,89, 128

Proprionyl CoA carboxylase  37,72

Acetyl CoA carboxylase 109,115, 140


Synthetases: a ligase that forms 2 molecules along w/ the breakdown of a pyrophosphate bond (as in ATP breakdown)


Glutamyl cysteine synthetase 57

Glutathione synthetase 57-58

Glutamine Synthetase 64

Carbamoyl Phosphate Synthetase I 66

Argininosuccinate synthetase 66



LYASES: CLEAVES OR SYNTHESIZES C-C, C-O, C-N & OTHER BONDS BY OTHER MEANS THAN BY OXIDATION OR HYDROLYSIS (Distinguishes them from oxidoreductase & hydrolases).  THE REACTION FOLLOWS THE ARRANGEMENT:  A + B à C (thereby distinguishing them from transferases, which follow the arrangement:  A + B à C + D).


Aldolases: a lyase that results in the formation of a carbon-carbon bond by combining an aldehyde or ketone with another compound.


Fructose 1,6-bisphosphate aldolase 42,45,48

Fructose 1-P aldolase 49 [fructose intolerance]


Decarboxylases:  a lyase that catalyzes the removal of CO2.


            See Pyruvate Dehydrogenase Complex


Hydratases: a lyase that utilizes hydration in the formation of a C-O bond (used to be called hydrase)


Synthases: a lyase that catalyzes a synthesis that does not include breaking a pyrophosphate bond.


ATP synth 12,13,18

     *complex w/ H+ ATPase & F1/F0 ATPase)

Citrate Synthase 24,25,81,82

Glycogen Synthase 98, (D-form 101), 102,104,105, 139,142

FAS (fatty acid synthase) 109

HMG CoA synthase 124




Dehydrogenases: an oxidoreductase that facilitates passage of one hydrogen from one molecule to another, thereby oxidizing one & reducing the other.  In general, OHà =O  &  C-NH2 à C=NH dehydrogenases are NAD(P)-linked, whereas C-C à C=C dehydrogenases are FAD-linked.


Succinate dehydrogenase 17 [contains riboflavin (Vit. B2)]

Fatty acyl CoA dehydrogenase 17,34 [contains riboflavin (Vit. B2)]

Glycerol 3-Phosphate dehydrogenase 17, 117

Isocitrate dehydrogenase 24,25,81,82

Alpha-KDH (alpha-ketoglutarate DH) 24,27 [Thpp (Vit. B1)]


Pyruvate DH (complex) 26,27,77,80,81,142 [Thpp (Vit. B1)]

            Contains: pyruvate DH & dihydrolipoyl DH

Malate DH (shuttle) 29,44, 79

L-3-Hydroxy fatty acyl CoA DH 34

3-Phosphoglyceraldehyde DH 42, 45

Lactate DH 42, 44, 45, 58

Glucose-6-P-DH 52, 55, 58, 59, 116

6-Phosphogluconate DH 52, 58

Glutamate DH 63, 64, 77, 81, 82,133

Branched-chain amino acid DH 71 [maple syrup disease]

Alpha-KADH (Branched -chain alpha-keto acid DH) 72

B-hydroxybutarate dehydrogenase 125




Desaturases: an oxidoreductase that catalyzes desaturation (formation of a double bond) in a fatty acid.


Hydroxylases: an oxidoreductase that facilitates coupled oxidation of 2 donors, w/ incorporation of oxygen into one of the donors, oxidation of the other donor, & formation of water.


Phenylalanine hydroxylase 73


Oxidases: an oxidoreductase that catalyzes reactions in which molecular oxygen is reduced.


Cyt c oxidase 16,19 [cyanide poisoning]

Glutathione peroxidase 57,58

a.a. oxidase 74

Homogentisate (gentisic) oxidase 74

Mixed function oxidase 111



Oxygenases: an oxidoreductase that catalyzes the addition of oxygen into a molecule.


4-hydroxyphenylpyruvate dioxygenase 74


Reductases: an oxidoreductase that has reducing action; a hydrogenase


NADH-CoQ reductase 16,19

Cyt c reductase 16,19

2,4-dienoyl-CoA reductase 36

Aldol Reductase 50

Glutathione Reductase 57,58

DHPR (Dihydropteridine Reductase) 73

B-ketoacyl-ACP reductase 110

Crotonyl-ACP reductase 110





Glucose-1-P uridyl transferase 97-98, 105

Oligoglycan Transferase 98,105 [Cori’s disease]

      (debranching enzyme)

AT  (Acetyl transferase) 109

MT  (Malonyl transferase) 109

Carnitine acyltransferase I & II 32,35,114-115, 140, 148

            (Acylcarnitine-carnitine transporter)

Galactose-1-P uridyl transferase 50 [galactosemia]

B-ketoacyl-CoA transferase 125


Kinases: a transferase that transfers a high energy group (usually P from ATP) to an acceptor


Adenylate kinase 7,93

Creatine kinase 8

Succinate thiokinase 24

Nucleoside diphosphokinase 25

PDH kinase 27

Fatty Acid Thiokinase 32

Hexokinase 42,45-47,49,58,81-82

PFK1 (6-Phosphofructokinase) 42,45-47, ,81-82,88,111-113,142

Phosphoglycerate kinase 42,45

PK (Pyruvate kinase) 42,45,46,48,58,59,81,82,89,90,114, 142,144

   *L & M-type

Glucokinase 47,139

Fructokinase 49 [fructosuria]

Glyceraldehyde kinase 49

Galactose kinase 50

PEPCK (PEP-Carboxykinase) 87,89, 142

Protein kinase 90,93,100-104,112-114,119

PKA (cAMP-dependent Protein Kinase) 94,100-102,112,119,139, 142

Tyrosine kinase 94

Nucleotide diphosphokinase 98

Phosphorylase kinase 99-102,139,142 [subject to glycogen storage diseases]

AMP-activated protein kinase (see cAMP)

Glycerol kinase 117



Mutases (some):  a transferase or isomerase that shifts one group (e.g., acyl, amino, phospho, etc.) from one point to another on the molecule.

D-methylmalonyl CoA mutase 37

L-methylmalonyl CoA mutase (Req. Vit B12) 37, 72

Vitamin B12-dependent mutase 72

            *IF (intrinsic factor)

Phosphoglyceromutase 42,45

Phosphoglucomutase 50,97,105

Superoxide dismutase 56

Diphosphoglyceromutase 58



Phosphorylases: a transferase that catalyzes the breakage of a C-O bond by the addition of inorganic phosphate.

Glycogen Phosphorylase 97,104,105

Phosphorylase a & b 99,104

Muscle phosphorylase 99,105 [McArdle’s disease]

Liver phosphorylase a & b 100 [Her’s disease]


Polymerases: a transferase that catalyzes polymerization.


Transaldolases: a transferase that transfers an aldehyde residue (e.g., the shortening of sedoheptulose to form erythrose 4-P) [C7 + Glyceraldehyde 3-P (C3) à Erythrose 4-P (C4) + Fructose 6-P (C6)] 54,55


Transketolases: a transferase that catalyzes the transfer of a ketone residue.


TPP & Mg++ dependent transketolase 53, 55


Transaminases: a transferase that transfers an amino group from an amino acid to an alpha-keto acid, especially alpha-ketoglutarate (2-ketoglutarate).  Aka aminotransferase. [All use PyrP (Vit. B6)]

Aminotransferase 63,64,71,73,94, 133,142

Glutamate-pyruvate aminotransferase 65,66


Glutamate-oxaloacetate transaminase 66,79


Branched-chain a.a. transaminase 71

L-tyrosine aminotransferase 74


Not Categorized:



ATP/ADP translocase 18,78

Aconitase 24

Fumarase 24

Dihydrolipoyl transacetylase (Prt. Of PDH complex)

Enoylhydratase 34

B-ketothiolase 34, 124-125

GLUT-Isozymes 41,140

Enolase 42,45

Lactonase 52

Catalase 56

Glutaminase 64-65

Arginase 66

Ornithine-citruline antiporter 67,78

Ornithine transcarbamoylase 66

Arginosuccinase 66

Fumarylacetoacetate hydrolase 74

Phosphate-hydroxy symporter 78

Malate-aspartate shuttle 79

Glutamate-Aspartate antiporter

Glycogenin 97,98

Adenylate cyclase 102, 104,119

Amylo (alpha-1,4 à alpha 1,6) transglycosylase 98,105 [Andersen’s disease]        *branching enzyme

Lysosomal alpha-1,4-glucosidase [Pompe’s disease]

ACP (acyl carrier protein) 108

Enoyl-ACP-dehydratase 110

Citrate lyase

Malic enzyme 114,116

HMG CoA cleavage enzyme 124

Protease/ubiquitin 130