Question

one main distinguishing factor between simple diffusion and facilitated diffusion is the use of a _______ to allow molecules to move into or out of a cell.

nucleic acid.
phospholipid.
protein.
carbohydrate.
rewatch

Explanation:

Simple diffusion is the movement of molecules from high - to low - concentration without help. Facilitated diffusion uses transport proteins (channel or carrier proteins) to move molecules across the cell membrane down their concentration gradient. Nucleic acids store genetic information, phospholipids are part of the cell membrane structure, and carbohydrates can be energy sources or have structural roles, but they are not involved in this distinction.

Answer:

C. protein