| A | B |
|---|
| plasma membrane | the thin layer of lipids and proteins that sets a cell off from its surroundings and acts as a selective barrier to the passage of ions and molecules into and out of the cell |
| phospholipid | a molecule that is a constituent of the inner bilayer of biological membranes, having a polar head and nonpolar tail |
| cholesterol | an organic lipid molecule found in animal cell membranes that helps maintain membrane fluidity |
| glycoproteins | a macromolecule consisting of one or more polypeptides linked to short chains of sugars integral proteins a type of membrane protein that is permanently attached to the membrane |
| hydrophobic | water-fearing; nonpolar molecules |
| hydrophilic | water-loving; polar molecules |
| phospholipid bylayer | another term for the cell or plasma membrane |
| integral proteins | proteins embedded in the phospholipid bilayer |
| hormone binding sites | proteins on the outside of the membrane that allow specific hormones to bind |
| peripheral proteins | proteins on the surface of the plasma membrane |
| pumps for active transport | proteins in the plasma membrane that release energy and use it to move substances across the membrane |
| amphipathic | Molecule that has hydrophobic and hydrophilic regions |
