table 8-1 Some Inorganic Elements That Serve as Cofactors for Enzymes 2+ CF Cytochrome oxidase re2+ or Fe3+ Cytochrome oxidase, catalase, peroxidase Pyruvate kinase Hexokinase, glucose 6-phosphatase, pyruvate kinase Mn2 Arginase, ribonucleotide reductase Dinitrogenase 2+ Urease Se Glutathione peroxidase Carbonic anhydrase, alcohol dehydrogenase carboxypeptidases A and B
table 8-2 Some Coenzymes That serve as Transient Carriers of Specific Atoms or Functional Groups Examples of chemical Dietary precursor it Coenzyme groups transferred mammals Bi locvtIn Biotin Coenzyme A Acyl groups Pantothenic acid and other compounds 5-Deoxyadenosylcobalamin H atoms and Vitamin B12 (coenzyme B12) alkyl groups Flavin adenine dinucleotide Electrons Riboflavin(vitamin B2) Lipoate Electrons and Not required in diet acyl groups Nicotinamide adenine Hydride ion(: H) Nicotinic acid(niacin) dinucleotide Pyridoxal phosphate Amino groups Pyridoxine (vitamin B6) Tetrahydrofolate One-carbon groups Folate Thiamine pyrophosphate Aldehydes Thiamine(vitamin B,) The structure and mode of action of these coenzymes are described in Part Ill of this book
Table 8-1 Some enzymes containing or requiring inorganic elements as cofactors Table 8-2 Some coenzymes serving as transient carriers of specific atoms or functional groups Fel or Fes Cytochrome oxidase Examples of some Catalase chemical groups Dietary pre cursor Peroxidase Coenzyme transferred in mammals Cult Cytochrome oxidase Carbonic anhydrase Thiamine pyrophosphate Aldehyde Thiamin (vitamin B1) Alcohol dehydrogenase Flavin adenine Electrons Riboflavin(vitamin B) dinucleotide Hexokinase Glucose-6-phosphatase Nicotinamide adenine Hydride ion(: H:) Nicotinic acid (niacin) Pyruvate kinase Mn Arginase Coenzyme A Acyl groups pantothenic acid, plus Ribonucleotide reductase other molecules K Pyruvate kinase Pyridoxal phospha Amino groups Pyridoxine (vitamin B4) NP Urease 5- Deoxyadenosyl H atoms and alkyl Vitamin Bu cobalamin Mo Dinitrogenase groups (coenzyme Bu) Se Glutathione peroxidase Biocytin Biotin Tetrahydrofolate One-carbon groups Folate Lipoate Electrons and acyl Not required groups In The strueture and mode of action of these coenzymes are described in Part Ill of this book
NAD+ reactive site °wH2 nicotinamide CH2 NH2 oH。H n adenine O=P-O-CH2 N ribose OHOH 21
Hc H3C CH N CH NH- -Fe CH HO 0=c CH3 Heme OH