BIO 310 Chapter Notes - Chapter 11: Lipid Bilayer, Monolayer, Cytosol
Document Summary
Plasma membrane - protein-studded, fatty film used to separate and protect its chemical components from the outside environment. Nutrients will pass inward across the plasma membrane and waste will pass outwards, so that cell can grow and survive. Consists of 2-ply sheet of lipid molecules 5nm thick with proteins inserted throughout. Serves as barrier to protect contents of cell from escaping and mixing with outside environment. Membrane grows with cell without losing continuity and can self-heal without deflating. Functions of proteins in the plasma membrane. Proteins that allow specific, small molecules and ions to be imported and exported act as highly selective channels and transporters. Proteins that enable the cell to receive info about changes in the environment and respond to them appropriately. Many bacteria have only a single membrane, but eukaryotic cells also have internal membranes. Internal membranes enclose intracellular compartments, forming various organelles, such as the golgi apparatus, nucleus, endosomes, mitochondria, er, etc.
