cell transport Flashcards
diffusion of substance across a biological membrane, needing no input or energy
passive transport
movement of molecules of any substance regards to the concentration gradient (from the region of high
concentration to low concentration).
simple diffusion
diffusion of
free water across a selectively
permeable membrane, whether
artificial or cellular
Osmosis
ability of a surrounding
solution to cause a cell to gain or lose water and is greatly influenced by the concentration of solutes that cannot cross the membrane relative to the solute concentration
inside the cell. (related to osmosis)
tonicity
refers to the diffusion
of substances which
requires specific
structure such as
proteins and also does
not need energy for the
transport process
Facilitated diffusion
Two Types of Facilitated Diffusion
channel proteins and carrier proteins
transport proteins which serves a hydrophilic tunnel for certain atoms
Channel proteins
transports proteins that hold onto their passengers and change shape in a way that transports them across the membrane
carrier proteins
voltage across a membrane which acts as a battery or an energy source that affects the movement of charged substances across the membrane
Membrane potential
combination of forces acting on ions is called
electrochemical
gradient
process in which the membrane protein
enables the “downhill” diffusion of one solute to drive the “uphill”
transport of another.
Co-transport
mechanism used by large molecules such as proteins and polysaccharides and
other large particles crossing the membrane in bulk
Bulk Transport
Two Types of Bulk Transport
Exocytosis and Endocytosis
cells take in molecules and other materials by forming new vesicles from plasma membrane.
Endocytosis
used by secretory
vesicles in cells to export cellular
products
exocytosis
Types of Endocytosis
-Phagocytosis (“cellular eating”)
- Pinocytosis (“cellular
drinking”)
-Receptor
