Biol 1201 Exam 2 Gregg Latest Update Already Passed

Biol 1201 Exam 2 Gregg Latest Update Already Passed Plasma membrane A selectively-permeable phospholipid bilayer forming the boundary of the cells. Hydrophilic heads and hydrophobic tails peripheral proteins Bound to the surface of the membrane Integral proteins penetrate the hydrophobic core Transport proteins Span membrane. Allow passage of hydrophilic substances functions of plasma membrane transport, enzymatic activity, signal transduction, cell-cell recognition, intercellular joining, attachment to cytoskeleton and ECM. Remember that carbs in cell= cell recognition Permeability The easiest= small, non polar. Hardest= large ions Hydrophobic (non polar) Dissolve in lipid bilayer and pass through membrane Hydrophilic (ions/ polar) Do not cross easily passive transport Diffusion of a substance with no energy used. Uses carrier protein. For polar and hydrophobic Diffusion Tendency for molecules to spread out into available space Osmosis diffusion of water across a selectively permeable membrane How does water diffuse Area of low to high until equal Hypotonic (we always refer to environment) Water rushes inside (cell bursts) normal in plant cells hypertonic Solution leaves cell (cell shrivels) Isotonic Solution is equal! facilitated diffusion Passive transport with help by proteins Ion channels- facilitate transport ions Gated channels- open/ close active transport Moves against gradient. Needs ATP (energy). Uses integral and transport proteins. For ionic and large cotransport Transport with a membrane protein Cytoplasm has a HIGH concentration of K+ ions, how can they keep entering? Energy and active transport. Bulk transport occurs by extocytosis and endocytosis How do small vs large molecules enter bilayer? Small/ water- enter and leave through bilayer or by transport proteins Large- cross by vesticles Phagocytosis Cell uses its plasma membrane to engulf a large particle. (Think a= ate) Pinocytosis Cell drinking receptor-mediated endocytosis Imports