BIOL 2130 Lecture Notes - Lecture 9: Osmosis, Lysosome, Phagocytosis
Document Summary
Cells have the ability to: metabolize, digest food, dispose of wastes, reproduce, grow, move, respond to a stimulus. Solution- homogeneous mixture of two or more components: solvent- dissolving medium; typically water in the body, solutes- components in smaller quantities within a solution. The plasms membrane is a selectively permeable barrier: some materials can pass through while others are excluded, for example: Two basic methods of transport: passive process. No energy (atp) is required: active process. Diffusion: particles tend to distribute themselves evenly within a solution, driving force is the kinetic energy (energy of motion) that"s causes the molecules to move about randomly. Diffusion: molecule movement is from high concentration to low concentration, or down a concentration gradient, size of molecule and temperature affects the speed of diffusion. The smaller the molecule, the faster the rate of diffusion. The warmer the molecule, the faster the rate of diffusion. Solutes are lipid-soluble or small enough to pass through membrane pores.
