Question

lactase is a protein in the digestive tract that helps break down certain sugars found in milk. what is the main function of lactase?

to provide structure
to fight disease
to maintain homeostasis
to regulate cell reactions

Explanation:

Lactase is an enzyme. Enzymes are proteins that act as biological catalysts to regulate cell reactions (in this case, breaking down sugars). Proteins for structure (like collagen), fighting disease (antibodies), or maintaining homeostasis (e.g., some hormones) have different roles.

Answer:

to regulate cell reactions