BIOL 1103K Lecture Notes - Lecture 6: Pyrophosphate, Cell Membrane, Endocytosis
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Document Summary
Plasma membrane is common to all cells separate the internal cytoplasm from external environment of the cell. Phospholipid bilayer external surface lined with hydrophilic head. Plasma membrane is a fluid mosaic made of phospholipid bilayer. Plasma membrane is selectively permeable small non-charged molecules (co2 o2 glycerol, alcohol) freely cross the membrane by passing thru the phospholipid bilayer. Follow concentration gradient move from an area of high concentration to an area of low concentration. Simple diffusion is the movement of a solute from an area of high concentration to an area of low concentration. Facilitated diffusion solute combines with transporter proteins in the membrane to mover from high to low concentrations. Active transport solute movement requires transporter protein/atp to move from low to high concentrations. Diffusion movement of molecules down a concentration gradient. Equilibrium is when net movement stops solute concentration is uniform. Osmosis special case of diffusion focuses on water movement rather than solute.