Glyceraldehyde is a triose monosaccharide with chemical formula C3H6O3. It is the simplest of all common aldoses. It is a sweet, colourless crystalline solid that is an intermediate compound in carbohydrate metabolism. The word "glyceraldehyde" comes from combining glycerine and aldehyde, as glyceraldehyde is merely glycerine with one hydroxide changed to an aldehyde. Glyceraldehyde is produced from the action of the enzyme glyceraldehyde dehydrogenase, which converts glycerol to glyceraldehyde using NADP as a cofactor. When present at sufficiently high levels, glyceraldehyde can be a cytotoxin and a mutagen. A cytotoxin is a compound that kills cells. A mutagen is a compound that causes mutations in DNA. Glyceraldehyde is a highly reactive compound that can modify and cross-link proteins. Glyceraldehyde-modified proteins appear to be cytotoxic, depress intracellular glutathione levels, and induce reactive oxygen species (ROS) production. Glyceraldehyde has been shown to cause chromosome damage to human cells in culture and is mutagenic in the Ames bacterial test.