In breadmaking, the yeast initially respires aerobically, producing carbon dioxide and water. Like all lungless salamanders, it respires through its skin. The bacterium converts taurine to hydrogen sulfide when it respires taurine. For a plant to grow, it must photosynthesise more than it respires. Instead, it respires by diffusing oxygen from water through the thin membrane covering its body. A freshly laid egg consists almost exclusively of reserve, and hardly respires. To produce such structures, the plant requires ATP and respires more of its biomass. Like all of the plethodontids, it lacks lungs and respires through its moist skin.