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Biology Chapter 6
Biology Chapter 6 Vocab
Term | Definition |
---|---|
autotroph | an organism that produces its own nutrients from inorganic substances or from the environment instead of consuming other organisms |
photosynthesis | the process by which plants, algae, and some bacteria use sunlight, carbon dioxide, and water to produce carbohydrates and oxygen |
heterotroph | an organism that obtains organic food molecules by eating other organisms or their byproducts and that cannot synthesize organic compounds from inorganic compounds |
light reactions | the initial reactions in photosynthesis, which are triggered by the absorption of light by photosystems I and II and include the passage of electrons along the electron transport chains, the production of NADPH and oxygen gas, and the synthesis of ATP thr |
chloroplast | an organelle found in plant and algae cells where photosynthesis occurs |
thylakoid | a membrane system found within chloroplasts that contains the components for photosynthesis |
granum | a stack of thylakoids in a chloroplast |
stroma | in plants, the slender, upper part of the pistil |
pigment | a substance that gives another substance or a mixture its color |
chlorophyll | a green pigment that is present in most plant cells, that gives plants their characteristic green color, and that reacts with sunlight, carbon dioxide, and water to form carbohydrates |
carotenoid | a class of pigments that are present in the thylakoid membrane of plants and that aid in photosynthesis |
photosystem | in the thylakoid membranes of chloroplasts, a cluster of chlorophyll and other pigment molecules that harvest light energy for the light reactions of photosynthesis |
primary electron acceptor | in chloroplasts, an acceptor of electrons lost from chlorophyll a; found in the thylakoid membrane |
electron transport chain | a series of molecules, found in the inner membranes of mitochondria and chloroplasts, through which electrons pass in a process that causes protons to build up on one side of the membrane |
chemiosmosis | in chloroplasts and mitochondria, a process in which the movement of protons down their concentration gradient across a membrane is coupled to the synthesis of ATP |
Calvin cycle | a biochemical pathway of photosynthesis in which carbon dioxide is converted into glucose using ATP |
carbon fixation | the synthesis of organic compounds from carbon dioxide, such as in photosynthesis |
stoma | one of many openings in a leaf or a stem of a plant that enable gas exchange to occur |
C4 pathway | a carbon-fixing process in which carbon dioxide is bound to a compound to form a four-carbon intermediate |
CAM pathway | a water-conserving, carbon-fixing process; CAM plants take in carbon at night and fix it into various organic compounds and release it during the day |