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CELL TRANSPORT
Chapter 7.
PASSIVE TRANSPORT ACTIVE TRANSPORT
Passive Transport:
Movement of materials across the cell membrane without the use of cellular energy (ATP). 3 Types:
- DIFFUSION. Process by which materials move from an area of HIGH concentration to an area of LOW concentration. This movement is due to random molecular movement and collision.
Major Cell Organelle Involved?
- FACILITATED DIFFUSION. Uses protein channels in the cell membrane to move larger and/or charged molecules across the membrane quickly and efficiently. Each protein channel is specific to the molecule that is helps through the membrane
CELL TRANSPORT
3. OSMOSIS. (A type of facilitated diffusion) Simply understood as the diffusion of water through a selectively permeable membrane. Water has a hard time passing through the lipid bi-layer (because of the hydrophobic tails of the fatty acids), as a result water passes across the membrane through specific protein channels called AQUAPORINS.
Sum it up:
ALL 3 TYPES ARE PASSIVE, REQUIRE NO ENERGY & MOVE FROM HIGH CONCENTRATION TO LOW
CONCENTRATION!!
VOCAB:
1. ISOTONIC 4. OSMOTIC PRESSURE
2. HYPERTONIC 5. CONCENTRATION GRADIENT
3. HYPOTONIC
Think of it this way:
Water moves in a direction of LOW SOLUTE concentration to HIGH SOLUTE concentration
HOMEOSTASIS:
The ability of an organism to maintain a stable internal environment.
HOMEOSTASIS 7 CELLS
Chapter 7.
THE CELL AS AN ORGANISM Life on Earth exists in either UNICELLULAR OR MULTICELLULAR form. Both forms must be able to maintain HOMEOSTASIS.
UNICELLULAR LIFE o Entire organisms that consist of only one cell. o Single celled organisms can be either prokaryotic or eukaryotic.
MULTICELLULAR LIFE
Cells are interdependent, and become specialized.
Cell Specialization:
Multicellular organisms’ cells have the ability to specialize or become different from one another. Humans have approx. 210 different cell types Humans have MAD types of Cells!!
Levels of Organization:
Cellular Communication: Cells need and do communicate with each other in several ways. They can send chemical messages from cell to cell (hormones) in which specific receptors are needed, electrical messages as in the nervous system and from one cell to a neighboring cell via the cytoskeleton.
