Question

1. what substance does the liver make that is necessary to digestion, and how does this substance work in the digestive system?

Explanation:

The liver makes bile. Bile is stored in the gall - bladder and released into the small intestine. It emulsifies fats, breaking large fat droplets into smaller ones, increasing the surface area for lipase enzymes to act on and thus aiding in fat digestion.

Answer:

The liver makes bile. Bile emulsifies fats in the small intestine to aid in their digestion.