By fermentation the yeast species Saccharomyces cerevisiae converts carbohydrates to alcohols and carbon dioxide - for thousands of years the carbon dioxide has been used in baking and the alcohol in alcoholic beverages. It is also extremely important as a model organism in modern cell biology research, and is one of the most thoroughly researched eukaryotic microorganisms. Researchers have used it to gather information about the biology of the eukaryotic cell and ultimately human biology. Other species of yeast, such as Candida albicans, are opportunistic pathogens and can cause infections in humans. Yeasts have recently been used to generate electricity in microbial fuel cells, and produce ethanol for the biofuel industry.