Download VOCAB Chapter 7

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VOCAB Chapter 7- TRANSPORT
SELECTIVELY PERMEABLE (=SEMI-PERMEABLE): Refers to membranes that allow certain molecules to
pass through but keep other molecules out
EQUILIBRIUM: A state that exists when the CONCENTRATION of a substance IS THE SAME
throughout a space
CONCENTRATION: mass of a dissolved substance in a given volume
OSMOTIC PRESSURE:
Pressure exerted against a semi-permeable membrane caused by water moving by osmosis
ACTIVE TRANSPORT:
Process that REQUIRES ENERGY to move molecules across a cell membrane against a concentration
gradient (moves molecules from lower concentration → higher concentration)
PASSIVE TRANSPORT:
Process that moves molecules across a cell membrane WITHOUT USING ENERGY
DIFFUSION: Process by which molecules tend to move from an area where they are more concentrated to
an area where they are less concentrated
OSMOSIS: The diffusion of water through a selectively permeable membrane
FACILITATED DIFFUSION: movement of specific molecules across cell membranes with the help of
protein channels and carriers
EXOCYTOSIS: A process in which a cell releases large amounts of material when a VESICLE inside the
cell fuses with the cell membrane and releases its contents to the OUTSIDE
ENDOCYTOSIS: Process by which a cell takes material into the cell by infolding of the cell membrane and
enclosing it in a VESICLE
PINOCYTOSIS: Process by which a cell takes in liquid or small dissolved molecules from the surrounding
environment and encloses it in a vesicle
PHAGOCYTOSIS: process in which extensions of cytoplasm surround and engulf large particles or whole
cells and take them into the cell in a vesicle
VESICLE - A small membrane bound sac in a eukaryotic cell used to transport substances around within a
cell or contain them during exocytosis or endocytosis
CARRIER PROTEIN: An INTEGRAL MEMBRANE PROTEIN that moves molecules PASSIVELY across cell
membranes by attaching, CHANGING SHAPE, and flipping to the other side like a revolving door
AQUAPORIN: An INTEGRAL MEMBRANE PROTEIN that provides a passageway/tunnel across the cell
membrane through which WATER molecules can diffuse PASSIVELY during osmosis
ION CHANNEL: An INTEGRAL MEMBRANE PROTEIN that provides a passageway/tunnel across the cell
membrane through which IONS can diffuse PASSIVELY
SODIUM-POTASSIUM PUMP: (also called Na+-K+ pump)
A MEMBRANE PROTEIN that uses energy from ATP to ACTIVELY transport two K + ions INTO and three
Na+ ions OUT of cells
PROTON PUMP: (also called H+ pump)
A MEMBRANE PROTEIN that uses energy to ACTIVELY transport hydrogen ions (H +) across a cell
membrane
HYPOTONIC:
Describes a solution in which the solute concentration
OUTSIDE a cell IS LESS THAN the concentration INSIDE
ISOTONIC:
Describes a solution in which the solute concentration
OUTSIDE EQUALS the concentration INSIDE a cell
HYPERTONIC:
Describes a solution in which the solute concentration
OUTSIDE IS GREATER THAN the concentration INSIDE a cell
PLASM0LYSIS: The shrinking away of the cell membrane from the cell wall in a plant cell when placed in
a HYPERTONIC environment
CYTOLYSIS: The swelling and bursting of an animal cell when placed in a HYPOTONIC solution
CRENATION: The shrinking of animal cells when placed in an hypertonic solution
SOLUTE: Substance that is dissolved in a solvent to make a solution
SOLVENT: Substance in which a solute is dissolved
HOMEOSTASIS: Cells try to maintain stable internal conditions