1. HOMEOSTASIS AND TRANSPORT
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2. Passive Transport
Transport of materials across the cell membrane WITHOUT using energy
3 main ways
Diffusion
Osmosis
Facilitated Diffusion
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3. Passive Transport: Diffusion
The movement of a substance from an area of high concentration to an area of low concentration
Concentration gradient = the area where the diffusion is occurring
Anything can diffuse
Controlled by:
Temperature, pressure, concentration
HINT: EXCLUDES WATER
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5. Diffusion in a cell
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6. Passive Transport: Facilitated Diffusion
Diffusion of large particles across carrier proteins embedded in the cell membrane
Channel Proteins
Carrier Proteins
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8. Passive Transport: Osmosis
Diffusion of water
3 types of solutions:
Isotonic
Hypotonic
Hypertonic
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9. Passive Transport: Osmosis
Isotonic
Equal amounts of water and solute
Water diffuses in and out of cell equally
Cell is normal
Ex: Kool-aid made just right
Ex: Blood
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10. Passive Transport: Osmosis
Hypotonic
Area with high concentration of waters
Water diffuses into the cell
Cell swells up
Ex: Kool-aid made with 2 gallons of water and a ½ pack of kool-aid
Ex: Distilled water
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11. Passive Transport: Osmosis
Hypertonic
Area with a low concentration of water
Water diffuses out of cell
Cell shrinks and shrivels
Ex: Kool-aid made with 1 cup of water and 3 packages of kool-aid
Ex: Alcohol, Caffeine, Ocean water, Epson Salt
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13. Active Transport
The movement of a substance from an area of low concentration to an area of high concentration.
Transport of materials across the cell membrane WITH energy
2 ways:
Endocytosis
Exocytosis
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14. Active Transport: Endocytosis
Moving particles into the cell
2 types:
Pinocytosis – liquids
Phagocytosis – solids/food particles
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16. Active Transport: Exocytosis
Removal of waste products from the cell
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17. Transport and Homeostasis
In multicellular organisms
Many bodily functions rely on both active and passive transport
One of the most important is the Sodium (Na) Potassium (K) Pump
Needed for muscle contraction
In unicellular organisms
Contractile vacuole
Remove excess water
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