What kind of protein is lactase, the biomolecules that speeds up the breakdown of lactose?

Lactase is a protein (enzyme) that speeds up the breakdown of lactose (milk sugar) into the simple sugars (glucose and galactose). Lactase is found in the small intestine of mammals and it is abundant during infancy but declines with age. Lactase is produced by the enterocytes (cells) that covers the intestinal walls and it creates the chemical barrier through which food molecules must cross for absorption by the intestines.