Fungi must digest their food before it can pass through the cell wall into hyphae because they lack a digestive system like animals do.

Here's a breakdown:

* Fungi are heterotrophs, meaning they obtain nutrients from other organisms. They don't have mouths or stomachs to break down food.

* Their cell walls are rigid and impermeable to large molecules, including complex food sources like proteins, carbohydrates, and lipids.

* Fungi use enzymes to break down food externally. These enzymes are secreted from hyphae into the surrounding environment, where they digest complex food molecules into smaller, simpler molecules.

* The smaller, soluble molecules can then be absorbed through the cell walls of the hyphae and transported throughout the fungal body.

In summary: Fungi digest their food outside their bodies before it can enter their cells because their cell walls are not permeable to complex food molecules, and they lack the internal digestive systems of animals.