ap bio membrane structure and function
Terms in this set (31)
A molecule that has both a hydrophilic region and a hydrophobic region.
fluid mosaic model
The currently accepted model of cell membrane structure, which envisions the membrane as a mosaic of individually inserted protein molecules drifting laterally in a fluid bilayer of phospholipids.
penetrate the hydrophobic core of the lipid bilayer
not embedded in the lipid bilayer at all
proteins that span the plasma membrane creating a selectively permeable membrane that regulates which molecules enter and leave a cell
the process by which molecules move from an area of higher concentration to an area of lower concentration
a difference in the concentration of a substance across a distance
The movement of materials through a cell membrane without using energy
having a higher concentration of solute than another solution
having a lower concentration of solute than another solution
Having the same solute concentration as another solution.
diffusion of water through a selectively permeable membrane
the control of water balance
swollen as from a fluid; bloated
limp, weak, flabby
the contraction or shrinking of the cell membrane of a plant cell in a hypertonic solution in response to the loss of water by osmosis
when substances transport across cell membranes using protein carrier molecules
a transport protein in the plasma membrane of a plant or animal cell that specifically facilitates the diffusion of water across the membrane
A protein channel in a cell membrane that opens or closes in response to a particular stimulus.
the movement of materials through a cell membrane using energy
example of active transport
A concentration gradient created by pumping ions into a space surrounded by a membrane that is impermeable to the ions.
pumps H+ through the plama membrane of chloroplasts and miochondria
occurs when active transport of a solute indirectly drives transport of other substances
the cell secretes macromolecules by the fusion of vesicles with the plasma membrane
process by which a cell takes material into the cell by infolding of the cell membrane
A type of endocytosis involving large, particulate substances, accomplished mainly by macrophages, neutrophils, and dendritic cells.
A type of endocytosis in which the cell ingests extracellular fluid and its dissolved solutes.
The uptake of specific molecules based on a cell's receptor proteins
A membrane transport process that carries one substance in one direction and another in the opposite direction.
A membrane transport process that carries two substances in the same direction across the membrane.