If you have a well in your home, keep a close eye on the color of the water, which may tell you plenty about what might go on down under. If your well water turns an eerie blue or blue-greenish color, you have a problem related to either copper or zinc from bronze fixtures.
67 MembraneStructure andFunction Chapter Concepts 4.1 Plasma Membrane Structure and Function â¢ The plasma membrane regulates the passage ofmolecules into and out of the cell. 68â¢ The membrane contains lipids and proteins.
Plasma Membrane. All living cells, prokaryotic and eukaryotic, have a plasma membrane that encloses their contents and serves as a semi-porous barrier to the outside environment. The membrane acts as a boundary, holding the cell constituents together and keeping other substances from entering.The plasma membrane is permeable to specific molecules, however, and allows nutrients and other essential elements to enter the cell and waste materials to leave the cell.he membrane acts as a boundary, holding the cell constituents together and keeping other substances from entering. The plasma membrane is permeable to specific molecules, however, and allows nutrients and other essential elements to enter the cell and waste materials to leave the cell.