Question

some molecules are too big to pass through the phospholipid bilayer of the cell membrane. these molecules need to pass through that are embedded in the cell membrane.

oa proteins

ob ribosomes

oc cell wall

od carbohydrates

Explanation:

The cell membrane has embedded proteins that act as channels or transporters for large - sized molecules that cannot pass through the phospholipid bilayer. Ribosomes are involved in protein synthesis and are not part of the membrane transport mechanism. The cell wall is an outer - layer structure in some cells (not related to membrane transport in this context). Carbohydrates on the cell membrane are mainly for cell - cell recognition, not for transporting large molecules.

Answer:

A. proteins