| A | B |
|---|
| absorption spectrum | range of a pigment’s ability to absorb various wavelengths of light |
| action spectrum | graph of relative effectiveness of different wavelengths of radiation in driving a process |
| autotroph | obtains organic food molecules without eating other organisms |
| bundle-sheath cell | photosynthetic cell arranged into tightly packed sheaths around the veins of a leaf |
| C3 plant | uses Calvin cycle to incorporate CO2 into organic material |
| C4 plant | incorporate CO2 into a four-carbon compound |
| Calvin cycle | atmospheric CO2 fixation and reduction of the fixed carbon into carbohydrate |
| CAM plant | carbon dioxide enter open stomata at night forms organic acids which release CO2 for the Calvin cycle during the day when stomata are closed |
| carbon fixation | incorporation of carbon from CO2 into an organic compound by an autotrophic organism |
| carotenoid | accessory pigment (yellow or orange) in the chloroplasts of plants |
| chlorophyll | green pigment located within the chloroplasts of plants |
| chlorophyll a | blue-green photosynthetic pigment that participates directly in the light reactions |
| chlorophyll b | yellow-green accessory photosynthetic pigment that transfers energy to chlorophyll a |
| crassulacean acid metabolism (CAM) | metabolism in which carbon dioxide is taken in at night and incorporated into a variety of organic acids |
| cyclic electron flow | route of electron flow during the light reactions of photosynthesis that involves only photosystem I and that produces ATP but not NADPH or oxygen |
| electromagnetic spectrum | entire spectrum of radiation ranging in wavelength from less than a nanometer to more than a kilometer |
| glyceraldehyde-3-phosphate (G3P) | carbohydrate produced directly from the Calvin cycle |
| heterotroph | organism that obtains organic food molecules by eating other organisms |
| light reactions | convert solar energy to the chemical energy of ATP and NADPH |
| light-harvesting complex | proteins associated with pigment molecules that capture light energy and transfer it to photosystems |
| mesophyll | ground tissue of a leaf |
| mesophyll cell | loosely arranged photosynthetic cell located between the bundle sheath and the leaf surface |
| NADP+ | nicotinamide adenine dinucleotide phosphate |
| non-cyclic electron flow | route of electron flow during the light reactions of photosynthesis that involves both photosystems and produces ATP |
| PEP carboxylase | enzyme that adds carbon dioxide to phosphoenolpyruvate (PEP) to form oxaloacetate |
| photon | quantum |
| photophosphorylation | generating ATP from ADP and phosphate by means of a proton-motive force generated by the thylakoid membrane |
| photorespiration | pathway consumes oxygen and releases carbon dioxide making no ATP |
| photosynthesis | conversion of light energy to chemical energy that is stored in glucose |
| photosystem | light-capturing unit located in the thylakoid membrane |
| photosystem I | light-capturing units in a chloroplast’s thylakoid membrane; it has two molecules of P700 chlorophyll a at its reaction center |
| photosystem II | light-capturing units in a chloroplast’s thylakoid membrane; it has two molecules of P680 chlorophyll a at its reaction center |
| primary electron acceptor | accepts an electron from reaction center chlorophylls |
| reaction center | complex of proteins associated with two special chlorophyll a molecules and a primary electron acceptor |
| rubisco | ribulose carboxylase enzyme catalyzes the first step of the Calvin cycle |
| spectrophotometer | instrument that measures the proportions of light of different wavelengths absorbed and transmitted by a pigment |
| stoma | microscopic pore surrounded by guard cells in the epidermis of leaves and stems that allows gas exchange |
| stroma | fluid of the chloroplast surrounding the thylakoid membrane; involved in the synthesis of organic molecules from carbon dioxide and water |
| thylakoid | flattened membrane sac inside the chloroplast |
| visible light | portion of the electromagnetic spectrum detected as various colors by the human eye |
| wavelength | distance between crests of waves |
