Cells Flashcards
specialized structures in cells that perform specific functions
organelles
jelly-like substance that holds organelles
cytoplasm
a structure that encloses the cytoplasm
cell membrane/plasma membrane
the outermost component of a cell.
cell membrane or plasma membrane
Materials inside the cell are ____________
intracellular
Materials outside the cell are __________
extracellular
The _______________ is the model used to
describe the cell membrane structure.
fluid-mosaic model
the membrane contains ____________
phospholipids,
cholesterol, proteins, and carbohydrates
What are the 2 regions of phospholipids?
polar and nonpolar
Waht transport does not require
the cell to expend energy?
Passive membrane transport
What transport does require the cell to expend energy, usually in the form of ATP.
Active membrane transport
Passive membrane transport mechanisms
include
diffusion, osmosis, and facilitated
diffusion
Active membrane transport mechanisms include
active transport, secondary active transport,
endocytosis, and exocytosis.
Diffusion generally involves movement of substances in
a solution down a _________________
concentration gradient.
solution is generally composed of two major parts which is
solute and solvent
Solutes are substances dissolved in a predominant liquid or gas, which is called the
solvent
This movement from high concentration to a low
concentration is _____________
diffusion
______________ can diffuse directly
through the phospholipid bilayer.
Lipid soluble substances
_______________ such as ions, can
diffuse across the cell membrane only by
passing through cell membrane channels.
Water-soluble substances
Two classes of cell membrane channels include
leak channels and gated channels
channel that constantly allow ions to pass
through
leak channels
channel that limit the movement of ions
across the membrane by opening and closing
gated channels
the diffusion of water (a solvent)
across a selectively permeable membrane from
a region of higher water concentration to one of
lower water concentration
osmosis
Osmosis exerts a pressure, termed ______________, which is the force required to prevent movement of water across cell membrane
osmotic pressure