Please enable JavaScript.
Coggle requires JavaScript to display documents.
chapter 7 membrane structure and function - Coggle Diagram
chapter 7 membrane structure and function
staple ingredients of membranes
phospholipid
amphipathic
Having both a hydrophilic region and a hydrophobic region.
hydrophilic
water-loving
hydrophobic
water-fearing
fluid mosaic model
The currently accepted model of cell membrane structure, which envisions the membrane as a mosaic of protein molecules drifting laterally in a fluid bilayer of phospholipids.
integral protein
A transmembrane protein with hydrophobic regions that extend into and often completely span the hydrophobic interior of the membrane and with hydrophilic regions in contact with the aqueous solution on one or both sides of the membrane (or lining the channel in the case of a channel protein).
transport protein
A transmembrane protein that helps a certain substance or class of closely related substances to cross the membrane.
aquaporin
A channel protein in a cellular membrane that specifically facilitates osmosis, the diffusion of free water across the membrane.
transmembrane protein
A type of integral protein that spans the entire membrane.
peripheral protein
A protein loosely bound to the surface of a membrane or to part of an integral protein and not embedded in the lipid bilayer.
carbohydrates
cell to cell recognition
glycolipid
A lipid with one or more covalently attached carbohydrates.
selective permeability
A property of biological membranes that allows them to regulate the passage of substances across them.
diffusion
The random thermal motion of particles of liquids, gases, or solids. In the presence of a concentration or electrochemical gradient, diffusion results in the net movement of a substance from a region where it is more concentrated to a region where it is less concentrated.
The random thermal motion of particles of liquids, gases, or solids. In the presence of a concentration or electrochemical gradient, diffusion results in the net movement of a substance from a region where it is more concentrated to a region where it is less concentrated.
concentration gradient
A region along which the density of a chemical substance increases or decreases.
passive transport
The diffusion of a substance across a biological membrane with no expenditure of energy.
osmosis
The diffusion of free water across a selectively permeable membrane.
turgid
flaccid
Swollen or distended, as in plant cells. (A walled cell becomes turgid if it has a lower water potential than its surroundings, resulting in entry of water.)
plasmolysis
A phenomenon in walled cells in which the cytoplasm shrivels and the plasma membrane pulls away from the cell wall; occurs when the cell loses water to a hypertonic environment.
tonicity
The ability of a solution surrounding a cell to cause that cell to gain or lose water.
The ability of a solution surrounding a cell to cause that cell to gain or lose water.
isotonic
Referring to a solution that, when surrounding a cell, causes no net movement of water into or out of the cell.
hypertonic
Referring to a solution that, when surrounding a cell, will cause the cell to lose water.
hypotonic
Referring to a solution that, when surrounding a cell, will cause the cell to take up water.
osmoregulation
Regulation of solute concentrations and water balance by a cell or organism.
facilitated diffusion
The passage of molecules or ions down their electrochemical gradient across a biological membrane with the assistance of specific transmembrane transport proteins, requiring no energy expenditure.
channel proteins
ion channels
A transmembrane protein channel that allows a specific ion to diffuse across the membrane down its concentration or electrochemical gradient.
gated channels
A transmembrane protein channel that opens or closes in response to a particular stimulus.
active transport
The movement of a substance across a cell membrane against its concentration or electrochemical gradient, mediated by specific transport proteins and requiring an expenditure of energy.
sodium-potassium transport
A transport protein in the plasma membrane of animal cells that actively transports sodium out of the cell and potassium into the cell.
membrane potential
The difference in electrical charge (voltage) across a cell’s plasma membrane due to the differential distribution of ions. Membrane potential affects the activity of excitable cells and the transmembrane movement of all charged substances.
electrogenic pump
An active transport protein that generates voltage across a membrane while pumping ions
proton pump
An active transport protein in a cell membrane that uses ATP to transport hydrogen ions out of a cell against their concentration gradient, generating a membrane potential in the process.
exocytosis
) The cellular secretion of biological molecules by the fusion of vesicles containing them with the plasma membrane.
endocytosis
Cellular uptake of biological molecules and particulate matter via formation of vesicles from the plasma membrane.