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Published byNorman Hubbard Modified over 9 years ago
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Cytoplasmic Organelles Centrioles Made of microtubules. Small, paired, tiny structures near the nuclear envelope. Most active during cell division. They are not found in plant cells.
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Cytoplasmic Organelles: Centrioles
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Movement of Materials Through The Cell Membrane For a cell to maintain its internal environment, it has to be selective in the materials it allows to cross its cell membrane. Transport: How molecules and fluids pass through the cell membrane.
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Movement of Materials Through The Cell Membrane Movement of molecules across the cell membrane depends on: (A) concentration difference (B) membrane permeability (C) size and type of particle (D) temperature and pressure
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Movement of Materials Through The Cell Membrane Three types of passive transport (i.e., no energy is required). 1. Diffusion: The process by which molecules of a substance move from an area of higher concentration of that substance to areas of lower concentrations.
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Movement of Materials Through The Cell Membrane: Diffusion
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Movement of Materials Through The Cell Membrane 2. Osmosis: The diffusion of water molecules through a selectively permeable membrane from an area of higher concentration of water to an area of lower concentration of water. It continues until equilibrium is reached.
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Movement of Materials Through The Cell Membrane: Osmosis
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Movement of Materials Through The Cell Membrane 3. Facilitated diffusion: The use of carrier proteins to move lipid insoluble substances through the cell membrane. Like diffusion and osmosis, no energy is used, but a concentration difference must exist for movement to occur. Example, transport of glucose.
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Movement of Materials Through The Cell Membrane: Facilitated Diffusion
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Movement of Materials Through The Cell Membrane Active Transport It is an energy-requiring process. It enables substances that do not diffuse into the cell to move against the natural flow. That is, materials cross the plasma membrane against a concentration difference.
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Movement of Materials Through The Cell Membrane Three types of active transport 1. Individual molecules are carried through membrane-associated pumps. These pumps depend on energy (ATP).
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Movement of Materials Through The Cell Membrane For example, the sodium-potassium pump. It ushers out sodium ions (Na+) and brings in potassium ions (K+) across the cell membrane. These pumps are common in nerve and kidney cells.
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Movement of Materials Through The Cell Membrane: Active Transport
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