Question

1. the cell membrane contains molecules that function together as a barrier to the external environment. which structure is not matched to the correct function? carbohydrate molecules: act as small channels for substances to enter and exit the cell phospholipid molecules: create a bilayer to control movement of substances in and out of the cell protein molecules: transport substances and provide structure for the cytoskeleton cholesterol molecules: add strength to the membrane

Explanation:

Carbohydrate molecules on the cell - membrane mainly function in cell - cell recognition and adhesion, not as channels for substance transport. Phospholipid molecules form a bilayer that controls substance movement. Protein molecules can transport substances and contribute to cytoskeleton structure. Cholesterol molecules add strength to the membrane.

Answer:

A. carbohydrate molecules: act as small channels for substances to enter and exit the cell