Biology Chapter 7

39458641	hypotonic	less solute concentration than another solution
39458642	amphipathic	has hydrophilic and hydrophobic region
39458643	Davson-Danielli model	lipid bilayer model coated on both sides with hydrophilic proteins (sandwich model)
39458644	fluid mosaic model	model of membrane as a mosaic of amphipathic protein molecules bobbing in fluid bilayer of phospholipids
39458645	integral proteins	embedded in bilayer's core
39458646	peripheral proteins	loosely bound to membrane surface
39458647	glycolipid	carbohydrates proteins covalently bonded to lipids
39458648	glycoprotein	carbohydrates covalently bonded to proteins
39458649	channel protein	transport protein that functions by having a hydrophilic channel that certain molecules use as a tunnel through the membrane
39458650	aquaporin	channel protein that specifically facilitates osmosis
39458651	carrier protein	transport protein that holds onto passengers and change conformation to shuttle them across membrane
39458652	concentration gradient	path traveled in order to balance the concentration of a substance across a space
39458653	tonicity	solution's ability to to cause a cell to gain or lose water
39458654	isotonic	having same solute concentration as another solution
39458655	hypertonic	solution with higher solute concentration
39458656	osmoregulation	control of water balance
39458657	gated channel	ion channel protein that opens and closes by stimulus
39458658	electrochemical gradient	combination of chemical and electrical forces acting on an ion
39458659	membrane potential	energy source affecting traffic of all charged substances across a membrance
39458660	electrogenic pump	transport proteins that generate voltage across a membrane
40393332	selective permeability	the plasma membrane exhibits ________ ________; it allows some substances to cross it more easily than others
40393333	freeze fracture	a method of preparing cells for electron microscopy is called _____ ______, which splits a membrane along the middle of the phospholipid bilayer
40393334	temperature buffer	cholesterol is a _______ _________ for the membrane; it resists changes in membrane fluidity that can be caused by changes in temperature
40393335	transport protein	some hydrophilic substances can avoid the lipid bilayer by passing through this
40393336	turgid	_____ is a healthy state for most plant cells, where the cell wall exerts pressure to stop further intake of water
40393337	flaccid	if a plant's cells and their surroundings are isotonic, there is no net tendency for water to enter, and the cells become _______
40393338	plasmolysis	when a cell is in a hypertonic environment, the cell will lose water to its surroundings, shrink, and its plasma membrane will pull away from the wall
40393339	facilitated diffusion	many polar molecules and ions impeded by the lipid bilayer of a membrane diffuse passively with the help of transport proteins that span the membrane
40393340	ion channels; gated channels	____ ________ allow certaion ions to pass and they can function as _______ _____, where a stimulus causes them to open or close
40393341	active transport	to pump a molecule across a membrane agaist its gradient requires work; the cell must expend energy
40393342	sodium-potassium pump	a ______-_______ _____ exchanges sodium (Na+) for potassium (K+) across the plasma membrane of animal cells
40393343	voltages	all cells have _______ across their plasma membranes
40393344	membrane potential	the _______ ________ is an energy source that affects the traffic of all charged substances across the membrane
40393345	proton pump	the main electrogenic pump in plants, fungi and bacteria is a _______ _________, which actively transports hydrogen ions out of the cell
40393346	cotransport	a single ATP-powered pump that transports a specific solute can indirectly drive the active transport of several other solutes in a mechanism called _________
40393347	endocytosis	the cell takes in macromolecules and particulate matter by forming new vesicles from the plasma membrane
40393348	exocytosis	the cell secretes macromolecules by the fusion of vesicles with the plasma membrane