Figure 1.
(a) A general map of core metabolism. The arrows in the map do not cover every atom in every cofactor, amino acid, or base, showing main mass contributions instead. A dot indicates that radical S-adenosyl methionine (SAM) enzymes are involved in the biosynthetic pathway leading to the product. [S] indicates that sulfur is incorporated in the biosynthetic pathway. (b) Cofactors indicated by a star are required in the pathway from H2 and CO2 to pyruvate in either acetogens or methanogens or both. (c) The composition of cells in terms of its main components and elemental contributions to dry weight (from [31]).