Final answer:
The channel and carrier molecules in the cell membrane that assist with the movement of materials are primarily made of proteins.
Step-by-step explanation:
The channel and carrier molecules that help move materials across the cell membrane are made primarily of proteins. These proteins can span the entirety of the membrane, forming channels, or bind substances on one side of the membrane and carry them to the other, like carrier proteins.
The cell membrane's structure is described by the fluid mosaic model, which includes a phospholipid bilayer that provides the basic structural framework. This bilayer is embedded with a variety of proteins and, in animal cells, cholesterol, which contributes to the membrane's fluid nature. Additionally, carbohydrates can attach to proteins and lipids on the outer surface of the membrane, but they are not the primary material of the transport structures.