1. Entry slip: When and where is Gustave available for
tutoring??
Get A Textbook!!!!
Lesson 5.6 Explain how cell membranes regulate
the movement of materials into and out of cells.
(pp50-63 of McGraw-Hill Ryerson)
I. Terms:
a.Extracellular: outside the cell.

2. i. Extracellular fluid: water with various
nutrients/gases/ hormones and
wastes dissolved in it
b.Intracellular: inside the cell.
i. Intracellular fluid: same as
extracellular fluid, except inside the
cell
c. Blood plasma: water with various
molecules dissolved within
d.Polar: the molecule is electrically charged.
It therefore dissolves in water which is
also charged; i.e. salt/sugar
e.Non-polar: the molecule has no charge. It
therefore does not dissolve in water: i.e.
oil/fat
f. Endocytosis: moving into the cell
g.Exocytosis: moving out of the cell
II. Cell Membranes
a. The outer layer of all cells. Outside of the
membrane is blood plasma-like

3. extracellular fluid, inside is intracellular
fluid.
b.Cell membrane is composed of a
“Phospholipid bilayer”
i. “Phospho-” means it contains a
phosphorus atom in the polar head
ii. “Lipid”- means long hydro-carbon
chains containing hydrogen and
carbon only; non-polar
iii. “Bi-layer”-means that the membrane
is made of two layers of
phospholipids stacked beside each
other. (see page 51)
c. Smaller compounds can move into or out
of the cell membrane fairly easily.
d.Larger compounds and ions (electrically
charged), however, either get trapped in
the polar “head” of the phospholipid
molecules when trying to pass through, or
get trapped in the non-polar hydrocarbon

4. “tail”. These compounds need special
pathways to get through.
III. Movement Processes:
a.Passive Transport (high to low
concentration)
i. The molecules going in and coming
out of the cells are “going down the
concentration gradient”- they are
going from an area of high
concentration to an area of low
concentration. This is like what
happens in external respiration when
O2 from O2-rich air in the lungs
diffuses across the alveolar wall to
the O2-poor blood. No energy
required!
ii. Channel proteins: special pathways
through the membrane that allow
charged (polar) particles like Na+ ions
to get through without getting
trapped in the non-polar phospholipid
“tails”

5. iii. Carrier proteins: special pathways
that allow non-polar molecules, like
lipids, through the layer without
getting trapped in the polar
phospholipid “heads”.
b.Active Transport (low to high
concentration)
i. Sometimes, molecules need to be
transported from an area of low
concentration to high concentrations,
which is the opposite way of which
they want to diffuse to.
ii. Energy required! Just like trying to
push a ball up a hill, energy is
required to make the ball go in the
opposite direction from which it
wants to go. As all cells at some point
have to actively transport materials
in/out of the cell, this is major reason
why we need energy from glucose to
stay alive!

6. iii. Special “cell membrane proteins” in
the membrane layer “grab” desired
molecules and change shape to move
the molecules to the other side.
IV.Demo: layering liquids
V. Youtube search:
VI.Passive & Active Transport -vanitavance
VII.Homework: