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29 Cards in this Set
- Front
- Back
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How are cell membranes fluid mosaic?
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they are composed of a bilayer of phospholipids with embedded and attached proteins
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What is selective permeability?
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the allowance of some substances to cross more easily than others
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What is diffusion?
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the tendency of particles to spread out evenly in an available space
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Which way does the concentration gradient flow?
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high to low
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What is passive transport?
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diffusion across a cell membrane that does not require energy
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What is osmosis?
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the diffusion of water across a selectively permeable membrane
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What does isotonic mean?
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concentration of a solute is the same on both sides, cell volume will not change
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What does hypotonic mean?
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solute concentration is lower outside the cell, water molecules move into the cell, cell will expand or burst
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What does hypertonic mean?
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solute concentration is higher outside of the cell, water moves out of the cell, cell shrinks
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What is osmoregulation?
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control of water balance
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What is facilitated diffusion?
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the passage of a substance through a specific transport protein across a biological membrane down its concentration gradient
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What is an aquaporin?
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a protein channel that makes rapid diffusion of water into/out of certain cells possible
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What is active transport?
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ATP energy is expended to move a solute against its concentration gradient
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What is exocytosis?
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exporting bulky molecules such as proteins or polysaccharides
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What is endocytosis?
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importing substances useful to the livelihood of the cell
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What are the 3 stages of endocytosis?
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phagocytosis, pinocytosis, receptor mediated endocytosis
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What is entropy?
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a measure of disorder or randomness
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What is cellular respiration?
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the chemical energy stored in organic molecules is converted to a form that the cell can use to perform work
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What is an exergonic (exothermic) reaction?
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releases energy
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What is an endergonic (endothermic) reaction?
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input/stores energy (ex: photosynthesis)
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What is ATP?
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a renewable energy source made of adenine triphosphate
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What is ATP used for?
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chemical work, mechanical work, transport work
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Describe an enzyme:
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very selective and precise in the reaction it catalyzes
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What are cofactors?
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nonprotein/inorganic helpers that enzymes require that bind to the active site and function in catalysis
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What is a coenzyme?
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a cofactor that is an organic molecule
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What are competitive inhibitors?
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block substrates from entering the active site, reduce productivity
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What is the difference between competitive and non competitive inhibitors?
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competitive inhibitors look like the substrate whereas non competitive inhibitors do not
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What is feedback inhibition?
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prevents a cell from wasting valuable resources by synthesizing more of a particular product that is needed.
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What are beneficial inhibitors?
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drugs
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