1. Cellular Transport

2. HOMEOSTASIS
THE PROCESS OF MAINTAINING A CONSTANT INTERNAL ENVIRONMENT DESPITE CHANGING EXTERNAL CONDITIONS

3. Figure 7-15 The Structure of the Cell Membrane
Section 7-3
Outside
of cell
Cell
membrane
Proteins
Protein
channel
Lipid bilayer
Carbohydrate
chains
Inside
of cell
(cytoplasm)
Go to Section:

4. CELL MEMBRANE IS SELECITVELY PERMEABLE
DIFFUSION OF MOLECULES OCCURS ACROSS THE CELL MEMBRANE

6. Movement through the Membrane
Diffusion
Osmosis Passive Transport
Facilitated Diffusion
Active Transport

8. PASSIVE TRANSPORT
MOVEMENT OF MOLECULES FROM AN AREA OF HIGHER CONCENTRATON TO AN AREA OF LOWER CONCENTRATION
KINDS:
DIFFUSION
OSMOSIS
FACILITATED DIFFUSION
DOES NOT REQUIRE THE USE OF ENERGY

9. DIFFUSION TERMS EQUILIBRIUM:
CONCENTRATION GRADIENT:
exists when particles are in higher concentration in one area and lower in concentration in another. Causes movement of the molecules
EQUILIBRIUM:
when the rate of particle spreading is even throughout a given area.

10. Osmosis
THE DIFFUSION OF WATER MOLECULES FROM AN AREA OF HIGHER CONCENTRATION TO AN AREA OF LOWER CONCENTRATION THROUGH A SELECTIVELY PERMEABLE LIPID BILAYER MEMBRANE WITHOUT ENERGY
When the transfer of water molecules into and out of the cell reaches the same rate, a state of equilibrium is reached.

11. Figure 7-17 Osmosis Cell membrane Section 7-3 Water molecules
Higher Concentration
of Water
Cell
membrane
Lower Concentration
of Water
Sugar molecules
Go to Section:

13. 3 Osmotic Solutions
Hypertonic
Hypotonic
Isotonic

14. Hypertonic
Cell shrinks, because water moves out of cell, because there’s more water in cell than in solution.
Salt water: 30% salt, 70% pure water
Cell: 80% water
start
end

15. Hypotonic
Cell swells (can burst), because water moves into cell, because there’s more water outside cell than in solution
Water: 100% pure water
Cell: 80% water
start
end

16. Water
Water
Hypertonic
Isotonic
Hypotonic

17. PROTEIN CHANNELS
PROVIDE OPENINGS THROUGH WHICH SPECIFIC SUBSTANCES CAN DIFFUSE ACROSS THE MEMBRANE
THESE PROTEINS ARE SELECTIVE
A PROTEIN CHANNEL EMBEDDED IN THE MEMBRANE PROVIDES A DIRECT PATH FOR A CHEMICAL TO PASS DOWN ITS CONCENTRATION GRADIENT, SO IT REQUIRES NO ENERGY

18. Facilitated Diffusion
Section 7-3
Glucose
molecules
High
Concentration
Cell
Membrane
Protein
channel
Low
Concentration
Go to Section:

19. Active Transport
movement from an area of lower concentration to an area of higher concentration against the concentration gradient using energy
Endocytosis – taking in materials by forming pockets
Phagocytosis – taking in large particles
Pinocytosis – taking in liquid/fluids
Exocytosis – removing materials by fusing vacuoles