All blood leaving the digestive system is routed directly to the , which gets a "first pass" at taking nutrients out of the blood and chemically altering them before sending out for other organs to use.

Long term exposure to waves can cause sunburns and skin cancer.

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.

Wich is not standing in the way of astronomers getting a good view of different star