BIOMOLECULES AND ENZYMES

Detailed explanation-1: -Carbohydrates on the cell membrane help cells function properly. Carbohydrates do this in two ways: helping cells recognize each other and providing protection for cells.

Detailed explanation-2: -Therefore the correct answer is D) controlling movement into the nucleus since the cell membrane is not responsible for this function.

Detailed explanation-3: -Carbohydrates covalently linked to proteins (glycoproteins) or lipids (glycolipids) are also a part of cell membranes, and function as adhesion and address loci for cells. The Fluid Mosaic Model describes membranes as a fluid lipid bilayer with floating proteins and carbohydrates.

Detailed explanation-4: -Glycolipids, glycoproteins, and proteoglycans are all components of the cell membrane. Glycolipids are a carbohydrate plus a lipid.