Table 1.

Number of chemicals and enzymes in each metabolic pathway type.

Metabolic pathway type	Number of chemicals	Number of enzymes
Carbohydrate metabolism	399	274
Energy metabolism	153	102
Lipid metabolism	405	337
Nucleotide metabolism	135	113
Amino acid metabolism	427	215
Metabolism of other amino acids	132	106
Glycan biosynthesis and metabolism	22	156
Metabolism of cofactors and vitamins	303	175
Metabolism of terpenoids and polyketides	195	46
Biosynthesis of other secondary metabolites	326	54
Xenobiotics biodegradation and metabolism	422	141
Total numbers of chemicals/enzymes in all pathway types	2919	1719
Number of different chemicals/enzymes	2329	1124