endocytosis + exocytosis worksheet Flashcards
the energy-requiring movement of substances across a biological membrane against a concentration gradient
active transport
protein channel that increases the diffusion rate of water through the plasma membrane
aquaporin
protein in the plasma membrane that facilitates the diffusion of a specific lipid insoluble molecule
carrier protein
a structure, present in plants and bacteria, which is found outside the plasma membrane and gives rigidity to the cell
cell wall
protein that provides a channel through the plasma membrane for small polar molecules and ions
channel protein
the gradual difference in the concentration of solutes as a function of distance through the solution
concentration gradient
the passive movement of molecules from high to low concentration
diffusion
active transport in which molecules are engulfed by the plasma membrane, forming a phagosome or food vacuole within the cell
endocytosis
active transport process by which membrane-bound secretory vesicles fuse with the plasma membrane and release the vesicle contents into the external environment
exocytosis
a type of passive transport facilitated by transport proteins
facilitated diffusion
the model for membrane structure which proposes a double phospholipid bilayer in which proteins and cholesterol are embedded
fluid mosaic model
lipids with attached carbohydrates which serve as markers for cellular recognition
glycolipids
membrane-bound proteins with attached carbohydrates, involved in cell to cell interactions
glycoproteins
a solution with higher solute concentration relative to another solution (across a membrane)
hypertonic
a solution with lower solute concentration relative to another solution (across a membrane)
hypotonic
a transmembrane protein that moves ions across a plasma membrane for small polar molecules and ions
ion pump
solutions of equal solute concentration
isotonic
passive movement of water molecules across a selectively permeable membrane down a concentration gradient
osmosis
movement of substances across a biological membrane without energy expenditure
passive transport
a specific form of endocytosis involving the engulfment of solid particles by the plasma membrane
phagocytosis
the uptake of liquids or fine suspensions by endocytosis
pinocytosis
a selectively permeable phospholipid bilayer forming the boundary of all cells
plasma membrane
the process in plant cells where the plasma membrane pulls away from the cell wall as a result of the loss of water through osmosis
plasmolysis
a membrane that acts selectively to allow some substances, but not others, to pass
selectively permeable
protein that spans the plasma membrane
transmembrane protein
the force exerted outward on a plant cell wall by the water contained in the cell
turgor
