Question

Explain why large molecules need to broken down into small molecules in the digestive system?

Answer 1

So that they can be easily absorbed.

Explanation:

Some big molecules have no use for us, only its constituents, and so enzymes assist in breaking it down for us. The small molecules therefore become soluble, and are easily absorbed into the bloodstream, for the making of proteins, lipids, and more substances that are essential for survival. Also, they might need to pass some membranes, and so when they are small, they can easily pass through.