glycolysis

citric acid cycle
electron transport 

etc

glucose-6-phosphate isomerase

pyruvate dehydrogenase

cyclooxygenase (2 isozymes)

phosphofructokinase

citrate synthase

dihydrofolate reductase

triose phosphate isomerase

aconitase

thymidylate synthase

glyceraldehyde 3-phosphate dehydrogenase

succinyl-CoA synthetase
(αβ dimers)

HMG-CoA reductase

enolase (3 isozymes)

succinate dehydrogenase
(heterotetramer)

GTP cyclohydrolase I

pyruvate kinase

fumarase

phenylalanine hydroxylase

lactate dehydrogenase
(5 isozymes)

cytochrome c oxidase subunit II

carbonic anhydrase
(many isozymes)

phosphoenol pyruvate carboxykinase

glucose 6-phosphate dehydrogenase

xanthine oxidase

pyruvate carboxylase

superoxide dismutase
(3 isozymes)

indolamine 2,3-dioxygenase

hypoxanthinegluanine phosphoribosyl transferase (HGPRT)