Download Membrane Transport

Membrane Transport
Membrane Transport

What are some
substances
commonly
transported across
membranes?
Membrane Transport

What are the three
mechanisms used
to move solute
molecules across
the membrane?
Simple Diffusion


What is involved in
this transport
process?
What can cross
the plasma
membrane via
simple diffusion?
Simple Diffusion

How does osmosis
differ from simple
diffusion?
Simple Diffusion

What are the major factors that influence
diffusion across a membrane?
Simple Diffusion

What specifically determines the
rate of simple diffusion?
vinward = PΔS
P = permeability coefficient
ΔS = concentration gradient
Simple Diffusion

What is the
partition
coefficient and
how does it
affect diffusion?
Facilitated Diffusion

How is facilitated diffusion different from
simple diffusion?
Facilitated Diffusion


What do we know about
transporters?
What is the difference between a
transporter or carrier protein and a
channel protein?
Facilitated Diffusion
Facilitated Diffusion


In what ways do transporters
resemble enzymes?
What kinds of molecules are
transported via facilitated diffusion?
Facilitated Diffusion

What do we specifically know about the
transport of glucose in red blood cells?
Facilitated Diffusion

What is the difference between ion
channels, porins and aquaporins?
Active Transport

How is active transport similar to
and different from facilitated
diffusion?
Active Transport

What is the difference between direct and
indirect active transport?
Active Transport

How can we calculate the energy
needed to transport uncharged
molecules across a membrane?

ΔG = RT ln [S]inside/[S]outside
free energy need to transport molecules from
outside to inside of membrane
Active Transport

If the solute being transported has
a charge how does that affect the
energy requirement?

ΔG = RT ln [S]inside/[S]outside + zFVm
z = charge on ion
F = 23,062 cal/mol-V (Faraday constant)
Vm = membrane potential – in volts
Sum of concentration & charge gradients =
electrochemical gradient
Active Transport

What are the four types of transport
ATPases?
Active Transport

What do we currently know about the
sodium-potassium pump?
Active Transport
Active Transport

Why is this sodium-potassium pump
so important for animal cells?
Active Transport

Why is the Na+/glucose symporter
an example of indirect active
transport?
Active Transport
Active Transport

What does the
bacteriodopsin
pump do and
where is it found?
Active Transport