Download Chapter 5 Homeostasis and Cell Transport

Chapter 5 Homeostasis and Cell Transport
Chapter 5: Homeostasis and Cell Transport
Explain how an equilibrium is established as a result of diffusion.
Distinguish between diffusion and osmosis.
Explain how substances can cross the cell membrane through facilitated diffusion.
I. PASSIVE TRANSPORT (No Energy needed)
1. Passive Transport
2. Diffusion = movement of molecules from areas of high concentration to low
concentration.
3. Occurs because kinetic energy
4. Diffusion works toward equilibrium
5. Concentration gradient = differences in concentrations over a distance
III. Osmosis (No Energy needed)
1. The process by which water molecules diffuse across a membrane from an
area of higher concentration to lower concentration.
2. Hypotonic solution = when concentration of water is higher outside the cell =
cell grows
3. Hypertonic solution = when concentration of water is lower than inside the
cell = cell shrinks
4. Isotonic solution = when concentrations are equal = cell stays the same
III. Facilitated Diffusion (No Energy needed)
1. Passive transport where transport proteins are needed.
2. Carrier protein = proteins that transport materials across the cell membrane
3. Example = transport of glucose
IV. Ion Channels (No Energy needed)
1. Transports ions from high concentrations to low concentrations.
2. Transports
a. Ca = Calcium
b. Na = Sodium
c. K = Potassium
d. Cl = Chloride
ACTIVE TRANSPORT
I. Active Transport (Energy needed)
1. Moving materials from areas of low concentration to high concentration
2. Some form of energy is needed.
3. Cell Membrane pumps
4. Carrier proteins and ion channels that require energy
III. Sodium-potassium pump (Energy needed)
1. Transports sodium and potassium
IV. Movement in Vesicles (Energy needed)
2. Endocytosis
3. Process by which cells take in large molecules including other cells.
4. Pinocytosis
5. Involves transport of fluids
6. Phagocytosis
7. Transport of large molecules or other cells
V. Exocytosis (Energy needed)
1. When a cell releases molecules like proteins and wastes