1. Chapter 8: Cellular Transport and the Cell Cycle

2. There are two types of cellular transport:
I. Passive
Transport -
particles move
from high to low
concentration;
CELL ENERGY
IS NOT
REQUIRED!

3. II. Active Transport – moves particles from low to high concentration; CELL ENERGY IS REQUIRED
NOTE:
There is a
greater
concen-tration of
particles
inside the
cell than
outside
the cell
Click in box to play movie

4. Types of passive transport
A. DIFFUSION
the random motion of particles from an area
of high concentration to an area of low
concentration until dynamic equilibrium is
reached.

5. 1. Diffusion of water – Osmosis
sugar
semi permeable
membrane
On the left side of the membrane the concentration of
water is greater than the concentration of sugar. Water
moves via osmosis to the other side of the U-tube.

6. Concentration gradient
2. Facilitated diffusion – with a concentration
gradient, carrier proteins move materials
across the plasma membrane.
Carrier Proteins
Concentration gradient
Plasma membrane

7. 3. Filtration – pressure gradient pushes
solute-containing fluid through a membrane
from higher pressure area to lower pressure
area.
Coffee pot
works this way
Kidneys also work this way

8. II. Types of active transport
A. endocytosis – material is engulfed and enclosed by the plasma membrane and brought into the cell
Types of
endocytosis:
1. pinocytosis – bringing in liquids
2. phagocytosis – bringing in solids

9. A second type of active transport:
B. exocytosis – getting rid of large particles
Wastes
Digestion
Exocytosis
Endocytosis

10. A solution is a mixture in which one or more
Review
A solution is a mixture in which one or more
substances are distributed evenly in another
substance.
sweet tea
solute – what gets
dissolved (sugar)
solvent – what
does the dissolving
(water)

11. How a cell reacts in types of solutions:
Isotonic Solution
(iso – same)
concentrations
of solute and solvent are the same inside and outside a cell or membrane
no net
movement

12. cell will swell Hypotonic Solution
(hypo – below, solute concentration is lower in solution than in cell, solvent
concentration is higher in solution)
solvent (water)
will move into
the cell
cell will
swell

13. cell will shrink Hypertonic Solution
(hyper – above, concentration of solute is greater in solution, solvent concentration is lower)
solvent (water)
will move out
of cell
cell will
shrink