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23 Cards in this Set
- Front
- Back
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What does active transport require?
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carrier proteins
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Describe what the sodium-potassium pump in active transport does and where it is located.
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Maintains electrochemical gradients essential for funtions of muscle and nerve tissues, it is located in all plasma membranes
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What are the steps in the sodium pottasium pump?
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1. Sodium binds to pump protein.
2. the binding of the sodium cause phosporilation of the protien by ATP 3. Phosphorilation causes a change in the shape of the protein expelling the sodium to the outside of the cell. 4. Extracellular potassium binds to the pump 5. pottasium binding causes release of phosphate and the pump returns to its normal shape. 6. Pottasium is released again and sodium is ready to bind again. |
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What is contransport?
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transport that always transports more than one substance at a time
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What is a symport system?
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when two substances are transported in the same direction
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What is antiport system?
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when two substances are transported in different directions
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What is vesicular transport and what does it use?
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transport of large particles, macromolecules, and fluids across plasma membranes, requires cellular energy
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What are some of the functions of vesicular transport?
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exocytosis, endocytosis, and transcytosis (transport into, across, and then out of cell)
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What is substance trafficking?
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transport from one area or organelle in cell to another
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what is phagocytosis?
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when pseudopods engulf solids and bring them into the cells interior
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What is pinocytosis?
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when the plasma membrane infolds, bringing extracellular fluid and solutes into the cell
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Receptor mediated endocytosis
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clathrin-coated pits provide main route for endocytosis and transcytosis
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Examples of exocytosis
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hormone secretion, neurotransmitter release, mucus secretion, and ejection of waste
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The process of exocytosis:
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1. The membrane-bound vesicle migrates to the plasma membrane
2. proteins at the vesicle surface and bind with t-snares 3. the vesicle and plasma membrane fuse and a pore opens up 4. vesicle contents are released to the cell exterior |
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What creates a cell's membrane potential?
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seperation of oppositely charged particles (ions) across a membrane
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What is the range of Resting Membrane Potential and what causes it?
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RMP ranges from -50 to -100 this results from diffusion and active transport ions (mostly K)
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Steps in the generation and matinence of RMP
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1. K diffuses down their steep concentration gradient (out of the cell) via leakage channels. Loss of K results in negative charge on the inner plasma membrane.
2. K moves into the cell bc they are attracted to the negative charge established on the inner plasma membrane 3. a negative membrane potential is established when movement of K out of the cell equals K movement into the cell. At this point the concentration gradient promoting K exit exactly opposes electrical gradient for Kentry |
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Cell enviornment reactions involve waht proteins?
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glycoproteins and glycocalyx
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What are the roles of Cell Adhesion Molecules?
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1. Anchor cells to extracellular matrix or to each other
2. assist in movement of cells past one another 3. attract white blood cells to areas of infection 4. Stimulate synthesis or degradation of adhesive membrane junction 5. transmit intracellular signals to direct cell migration and specilation |
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Roles of Membrane receptors
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contact signaling, chemical signaling, and G-protein linked receptors
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What is contact signaling?
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toucing and recognition of cells
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chemical signaling
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interaction between receptors and ligands to alter activtity of cell proteins
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What is the role of Gprotein linked receptors?
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ligand binding activates a G protein affecting ion channel or enzyme or causing the release of and internal second messenger such as cyclic AMP
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