the various functions of membrane proteins.
Junctions – Serve to connect and join two cells together.
Enzymes – Fixing to membranes localises metabolic pathways.
Transport – Responsible for facilitated diffusion and active transport.
Recognition – May function as markers for cellular identification
Anchorage – Attachment points for cytoskeleton and extracellular matrix
Transduction – Function as receptors for peptide hormones
a chart with the various membrane transport mechanisms, explain how they work and create a small
drawing showing that mechanism
MEMBRANE
TRANSPORT
MECHANISM
EXPLANATION (HOW
DOES IT WORK?)
Passive
transport
small uncharged solute
particles diffuse across
the membrane until both
sides of the membrane
have reached an
equilibrium that is similar in
concentration. The
direction of solute travel is
indicative of the
concentration of that
particular particle on
each side of the
membrane.
Facilitated
Diffusion
Facilitated diffusion allows
the passage of
lipophobic molecules
through the cell
membrane’s lipid
bilayer.2 Just as in passive
transport, molecules,
particles, and ions travel
freely across the cellular
membrane from high
concentration to low
concentration in an
attempt to achieve
equilibrium and thereby
increase the entropy of
the system. Also like
passive transport, the
Gibbs Free Energy of the
system is negative,
allowing the particle
movement to be
spontaneous.4 Facilitated
diffusion, however, uses
DRAWING (SKETCH)
channel proteins to
facilitate solute
movement.
Active
Transport
is the movement of
particles through a
transport protein from low
concentration to high
concentration at the
expense of metabolic
energy.21 The most
common energy source
used by cells is adenosine
triphosphate or ATP,
though other sources
such as light energy or the
energy stored in an
electrochemical gradient
are also utilized.