What does microscopic holes have to do with digestion

What does microscopic holes have to do with digestion?

The food needs to pass through our cell membranes or membranes in the villi of the small intestine. They have what could be called microscopic holes. It allows certain molecules like water to pass freely but other molecules can also pass but need some assistance. There are proteins that allow certain molecules like amino acids and simple sugars to pass but food needs to be digested before the molecules that can pass freely are produced like the simple sugars and amino acids.

http://www.vivo.colostate.edu/hbooks/pat…
http://www.vivo.colostate.edu/hbooks/pat…