BIOL 2443 Lecture Notes - Lecture 2: Cell Membrane, Facilitated Diffusion, Membrane Transport Protein
Document Summary
There are trillions of cells in the body: structural building blocks of all plants and animals, produced by the division of preexisting cells, form all the structures and perform all vital functions of the body. Two types of cells in the body (figure 2. 2): sex cells. Sperm in males and oocytes in females: somatic cells. All the other cells in the body that are not sex cells. Hydrophilic heads are at the surfaces (inside lining and outside lining) Hydrophobic fatty acids (tails) face toward each other . Cholesterol: functions of the plasma membrane: Cell-to-cell communication/adhesion/structural support: membrane permeability of the plasma membrane. Movement of molecules from an area of high concentration to an area of low concentration. Anything but water: passive process: osmosis. Movement of water molecules from an are of high concentration to high concentration. No energy required: passive process: facilitated diffusion. Solutes are passively transported by carrier protein. No extra energy required: active process: active transport.
