CELLULAR TRANSPORT AND HOMEOSTASIS
Organisms must maintain homeostasis
which can be done through the Active
and/or Passive Transport of materials
into and out of the cell
CELLULAR TRANSPORT AND HOMEOSTASIS
Active Transport is the net movement of
materials against the concentration
gradient or the movement of large
materials into or out of the cell
Requires Energy
CELLULAR TRANSPORT AND HOMEOSTASIS
Active Transport includes all of the
following types of transport:
1. Small molecule and ion transport by
protein pumps (Na+/K+ pump)
2. Bulk transport by endo- or exocytosis
(white blood cells engulfing harmful
bacteria)
CELLULAR TRANSPORT AND HOMEOSTASIS
Passive Transport is the net movement
of materials from a high concentration to
a low concentration into and out of a cell
DOES NOT Require Energy
CELLULAR TRANSPORT AND HOMEOSTASIS
Passive Transport includes all of the
following types of transport:
1. Diffusion (movement of CO2 across the
lipid bilayer into a plant cell)
2. Facilitated diffusion (movement of
glucose through a protein channel)
3. Osmosis (movement of H2O out of a
cell)
1
Is the net movement of water into
the cell or out of the cell?
2
Is this an example of active or
passive transport?
REMEMBER:
Organisms must maintain homeostasis
which can be done through the Active
and/or Passive Transport of materials
into and out of the cell
3
1. Hypotonic solutions have less
solute than solvent
2. Hypertonic solutions have more
solute than solvent
3. Isotonic solutions have an equal
amount of solute and solvent
What type of solution is this cell in:
hypo-, hyper-, isotonic?
4
When the cell has reached equilibrium
and homeostasis is reached how many
water molecules will be in the cell?
The diagram shows a
single-celled organism
called Paramecium,
which lives in freshwater
environments. This
organism contains a
specialized organelle
called a contractile
vacuole that helps
maintain osmotic
balance. Predict how
this organelle might
help the organism
survive given that it is
constantly immersed in
a hypotonic solution.
5