Chapter 10 Vocabulary

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Across
  1. 2. the ground tissue of a leaf, sandwiched between the upper and lower epidermis and specialized for photosynthesis.
  2. 7. spectrum The range of a pigment's ability to absorb various wavelengths of light; also a graph of such a range.
  3. 8. sheath cell in C4 plants, a type of photosynthetic cell arranged into tightly packed sheaths around the veins of A leaf.
  4. 9. adenine dinucleotide phosphate, An electron acceptor that, as NADPH, temporarily stores energized electrons produced during the light reactions.
  5. 13. a green pigment located within the chloroplasts of plants and algae and in the membranes of certain prokaryotes.
  6. 15. fixation the initial incorporation of carbon from CO2 into an organic compound by an autotrophic organism (a plant, another photosynthetic organism, or a chemoautotrophic prokaryote).
  7. 16. electron flow a route of electron flow during the light reactions of photosynthesis that involves only photosystem I and that produces ATP but not NADPH or O2.
  8. 18. an organism that harnesses light energy to drive the synthesis of organic compounds from carbon dioxide.
  9. 19. acid metabolism (CAM) an adaptation for photosynthesis in arid conditions, first discovered in the family Crassulaceae. In this process, a plant takes up CO2 and incorporates it into a variety of organic acids at night; during the day, CO2 is released from organic acids for use in the Calvin cycle.
Down
  1. 1. carboxylase an enzyme that adds CO2 to phosphoenolpyruvate (PEP) to form oxaloacetate in C4 plants. It acts prior to photosynthesis.
  2. 3. spectrum the entire spectrum of electromagnetic radiation ranging in wavelength from less than a nanometer to more than a kilometer.
  3. 4. reactions the first of two major stages in photosynthesis (preceding the Calvin cycle). These reactions, which occur on the thylakoid membranes of the chloroplast or on membranes of certain prokaryotes, convert solar energy to the chemical energy of ATP and NADPH, releasing oxygen in the process.
  4. 5. electron flow a route of electron flow during the light reactions of photosynthesis that involves both photosystems (I and II) and produces ATP, NADPH, and O2. The net electron flow is from H2O to NADP+.
  5. 6. an accessory pigment, either yellow or orange, in the chloroplasts of plants and in some prokaryotes. By absorbing wavelengths of light that chlorophyll cannot, they broaden the spectrum of colors that can drive photosynthesis.
  6. 10. An organism that obtains organic food molecules without eating other organisms or substances derived from other organisms. They use energy from the sun or from the oxidation of inorganic substances to make organic molecules from inorganic ones.
  7. 11. A quantum, or discrete quantity, of light energy that behaves as if it were a particle.
  8. 12. 3-phosphate (G3P)a three-carbon carbohydrate that is the direct product of the Calvin cycle; it is also an intermediate in glycolysis.
  9. 14. spectrum A graph that profiles the relative effectiveness of different wavelengths of radiation in driving a particular process.
  10. 15. cycle the second of two major stages in photosynthesis (following the light reactions), involving fixation of atmospheric CO2 and reduction of the fixed carbon into carbohydrate.
  11. 17. harvesting complex a complex of proteins associated with pigment molecules (including chlorophyll a, chlorophyll b, and carotenoids) that captures light energy and transfers it to reaction-center pigments in a photosystem.