Why is white matter "white"? Why is white matter "white"? It consists of cell bodies and unmyelinated fibers. The region contains a high concentration of the white pigment titanium dioxide. It contains a high concentration of myelin. Endoneurium is composed of a delicate connective tissue.

Lactase is essential for digesting lactose in milk. this enzyme is specific for this sugar. why? molecules and active sites vary in size; only properly sized molecules can fit.there is a precise compatibility between the active site and the lactose molecule.specificity refers to the action of the enzyme, such as hydrolysis, and relatively few molecules can be hydrolyzed.reaction-specific enzymes assume a fit by folding around the most numerous substrate molecules.