Biology Cell 2 – Flashcards
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The movement of the hydrophobic gas nitrous oxide (N2O) (laughing gas) into a cell is an example of
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Diffusion
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Which of the following would likely move through the lipid bilayer of a plasma membrane most rapidly?
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CO2
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Water passes quickly through cell membranes because
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It moves through aquaporins in the membrane
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Glucose diffuses slowly through artificial phospholipid bilayers. The cells lining the small intestine, however, rapidly move large quantities of glucose from the glucose-rich food into their glucose-poor cytoplasm. Using this information, which transport mechanism is most probably functioning in the intestinal cells?
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Facilitated diffusion
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Which of the following membrane activities requires energy from ATP hydrolysis?
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Movement of Na+ ions from a lower concentration in a mammalian cell to a higher concentration in the extracellular fluid
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The difference between pinocytosis and receptor-mediated endocytosis is that
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Pinocytosis is nonselective in the molecules it brings into the cell, whereas receptor-mediated endocytosis offers more selectivity.
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In active transport
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Molecules move across the plasma membrane against their concentration gradient.
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A molecule moves down its concentration gradient using a transport protein in the plasma membrane with no energy requirements. This is an example of
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Facilitated diffusion
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Water crosses the plasma membrane
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Through facilitated diffusion or diffusion
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The sodium-potassium pump uses energy from ATP to move sodium ions out of the cell, and potassium ions into the cell. This is an example of
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Active transport.
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The plasma membrane forms a pocket that pinches inward, forming a vesicle that contains material from outside the cell. This describes the process of
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Endocytosis
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Two cells are identical in every way except one has aquaporin proteins and the other relies on simple diffusion for osmosis to occur. What are logical outcomes of each situation?
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If placed in salt water the one without the proteins would shrivel slower than the other.
