Biology 151 Rated A+ 2025 New Update

Biology 151 Rated A+ 2025 New Update selective permeability - Answer - allowing some substances to cross it more easily than others amphipathic molecules - Answer - phospholipids are this. containing hydrophobic and hydrophilic regions fluid mosaic model - Answer - states that a membrane is a fluid structure with a mosaic of various proteins embedded in it membrane - Answer - a collage of different proteins, often grouped together, embedded in the fluid matrix of the lipid bilayer peripheral proteins - Answer - bound to the surface of the membrane integral proteins - Answer - penetrate the hydrophobic core transmembrane proteins - Answer - integral proteins that span the entire membrane concentration gradient - Answer - the region along which the density of a chemical substance increases or decreases passive transpor or osmosis - Answer - diffusion of a substance across a membrane with no energy investment osmosis - Answer - the diffusion of water across a selectively permeable membrane toniciy - Answer - the ability of a surrounding solution to cause a cell to gain or lose water isotonic solution - Answer - solute concentration is the same as ha inside the cell; no net water movement across the plasma membrane hypertonic colution - Answer - solute concentration is greater than that inside the cell;cell loses water hypotonic solution - Answer - solute concentration is less than that inside the cell; cell gains water turgid - Answer - a plant cell in a hypotonic solution swells until the wall opposes uptake; firm flaccid - Answer - a plant cell and its surroundings are isotonic, there is no net movement of water into the cell; limp plasmolsis - Answer - in a hyperonic environmen, plant cells lose water; eventually he membrane pulls away from the wall osmoregulation - Answer - he control of solute concentrations and water balance, is a necessary adaptaion for life in such environments glycolipids - Answer - when membrane carbohydrates may be covalently bonded to lipids or more commonly to proteins forming glycoproteins transport proeins - Answer - allow passage of hydrophilic substances across the membrane; example is aquaporin channel proteins - Answer - are transport proteins that have a hydrophilic channel that certain molecules or ions can use as a tunnel aquaporins - Answer - are channel proteins that facilitate the passage of water carrier proteins - Answer - are transport proteins that bind to molecules and change shape o shuttle them across the membrane facilitated diffusion - Answer - transport proteins sped the passive movement of molecules across the plasma membran channel proteins 2 types - Answer - aquaporins-for facilitated diffusion of water ion channels-open or close in response to a stimulus