The last blue box says “the temperature increases in the center of a nebula, and nuclei begin to fuse. (I couldn’t fit it in the pic) Question: Arrange the events in the life of a star in the correct order.

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.