Three young children are fighting over where to take Super Dog. Child X pulls the wagon, trying to go in the
direction of his house. Child Y pushes on the wagon
towards X's house. Child Z pushes the wagon in the
opposite direction. The forces the 3 children exert on the
wagon are 300 N, 500N, and 200N (not in any order).
The wagon isn't moving, how much force is child Z
pushing with?

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.