Vocab Flashcards
(a phospholipid that has) both a hydrophilic region and a hydrophobic region
Amphipathic
Where the membrane is envisioned as a mosaic of protein molecules drifting laterally in a fluid bilayer of phospholipids
Fluid-mosaic model
Proteins that penetrate the hydrophobic interior of the lipid bilayer
Integral proteins
Proteins that are not embedded in the lipid bilayer, but are loosely bound to the surface of the membrane
Peripheral proteins
Membrane carbohydrates that are covalently bonded to lipids
Glycolipids
Membrane carbs that are covalently bonded to proteins
Glycoproteins
Hydrophilic substances use these to avoid contact with the lipid bilayer
Transport proteins
A channel protein in the plasma membrane that specifically facilitates osmosis
Aquaporins
The movement of molecules of any substance so that they spread out evenly into the available space
Diffusion
The region along which the density of a chemical substance increases or decreases
Concentration gradient
The diffusion of a substance across a biological membrane
Passive transport
The diffusion of free water across a selectively permeable membrane
Osmosis
Ability of a surrounding solution to cause a cell to gain or lose water
Tonicity
No net movement of water across cell membrane when cell is in this environment
Isotonic
Cell will lose water, shrivel in this environment
Hypertonic
Cell will gain water and maybe burst in this environment
Hypotonic
The control of solute concentrations and water balance
Osmoregulation
(in hypertonic environment) as cell shrinks, plasma membrane pulls away from the wall
Plasmolysis
Polar molecules and ions impeded by the lipid bilayer of the membrane diffuse passively with the help of transports proteins that spanish the membrane
Facilitated diffusion
Channel proteins that transport ions
Ion channels
The voltage across the membrane
Membrane potential
A single ATP- powered pump that transports a specific solute can indirectly drive the active transport of several other solutes in a mechanism
Cotransport
When the cell secretes certain biological molecules by the fusion of vesicles with the plasma membrane
Exocytosis
When the cell takes in biological molecules and particulate matter by forming new vesicles from the plasma membrane
Endocytosis
Any molecule that binds specifically to a receptor site on another molecule
Ligands
