The fluids react with relatively acidic seawater to produce mineral structures full of tiny pores, where hydrogen and carbon dioxide come together to form simple molecules. (newscientist.com)
Enzyme functions; muscle and nerve - cell membrane stability; hormone secretion and function; mineral structure of bones and teeth (lowchensaustralia.com)
The CaCO3 also had a different mineral structure when the bacteria were around. (sciencemag.org)