Biology 1: Cells and Molecules
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| 1889713657 | autotroph | An organism that obtains organic food molecules without eating other organisms or substances derived from other organisms. _________s use energy from the sun or from oxidation of inorganic substances to make organic molecules from inorganic ones | 0 | |
| 1889713658 | bundle-sheath cell | In C4 plants, a type of photosynthetic cell arranged into tightly packed sheaths around the veins of a leaf | 1 | |
| 1889713659 | calvin 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 | 2 | |
| 1889713660 | C3 plant | A plant that uses the Calvin Cycle for the initial steps that incorporate CO2 into organic material, forming a 3-carbon compound as the first stable intermediate | 3 | |
| 1889713661 | C4 plant | A plant in in which the Calvin cycle is preceded by reactions that incorporate CO2 into a four-carbon compound, the end product of which supplies CO2 for the the Calvin cycle | 4 | |
| 1889713662 | CAM plant | A plant that uses crassulacean acid metabolism, an adaptation for photosynthesis in arid conditions. In this process, CO2 entering open stomata during the night is converted to organic acids, which release CO2 for the Calvin cycle during the day when the stomata are closed | 5 | |
| 1889713663 | chlorophyll a | A photosynthetic pigment that participates directly in the light reactions, which convert solar energy to chemical energy | 6 | |
| 1889713664 | cyclic electron flow | A route of electron flow during the light reactions of photosynthesis during the light reactions of photosynthesis that involves only one photosystem and that produces ATP but not NADHP or O2. | 7 | |
| 1889713665 | light 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 | 8 | |
| 1889713666 | linear electron flow | A route of electron flow during the light reactions of photosynthesis that involves both photosystems and produces ATP, NADPH, and O2. The net electron flow is from H2O to NADP+. | 9 | |
| 1889713667 | Light-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 | 10 | |
| 1889713668 | photosynthesis | The conversion of light energy to chemical energy that is stored in sugars or other organic compounds; occurs in plants, algae, and certain prokaryotes | 11 | |
| 1889713669 | photon | A quantum, or discrete quantity, of light energy that behaves as if it were a particle | 12 | |
| 1889713670 | Photosystem | A light-capturing unit located in the thylakoid membrane of the choroplast or in the membrane of some prokaryotes, consisting of a reaction-center complex surrounded by numerous light-harvesting complexes. There are two types of photosystems, I and II; they absorb light best at different wavelengths | 13 | |
| 1889713671 | primary electron acceptor | In the thylakoid membrane of a chloroplast or in the membrane of some prokaryotes, a specialized molecule that shares the reaction-center complex with a pair of chlorophyll a molecules and that accepts an electron from them | 14 | |
| 1889713672 | photosystem II | One of two light-capturing units in a chloroplast's thylakoid membrane or in the membrane of some prokaryotes; it has two molecules of P680 chlorophyll a at its reaction center | 15 | |
| 1889713673 | photosystem I | A light-capturing unit in a chloroplast's thylakoid membrane or in the membrane of some prokaryotes ; it has two molecules of P700 chlorophyll a at its reaction center | 16 | |
| 1889713674 | photorespiration | A metabolic pathway that consumes oxygen and ATP, releases carbon dioxide, and decreases photosynthetic output. Photorespiration generally occurs on hot, dry, bright days, when stomata close and the O2 CO2 ratio in the leaf increases, favoring the binding of O2 rather than CO2 by rubisco | 17 | |
| 1889713675 | NADP+ | An electron acceptor that, in its reduced state, temporarily stores energize electrons produced during the light reaction | 18 | |
| 1889713676 | thylakoid | A flattened, membranous sac inside a chloroplast. Thylakoids often exist in stacks called grana that are interconnected; their membranes contain molecular "machinery" used to convert light energy to chemical energy | 19 | |
| 1889713677 | stroma | The dense fluid within the chloroplast surrounding the thylakoid membrane and containing ribosomes and DNA; involved in the synthesis of organic molecules from carbon dioxide and water | 20 | |
| 1889713678 | visible light | That portion of the electromagnetic spectrum that can be detected as various colors by the human eye, ranging in wavelength from about 380nm to about 750nm | 21 | |
| 1889713679 | wavelength | the distance between crests of waves, such as those of the electromagnetic spectrum | 22 | |
| 1889713680 | reaction-center complex | A complex of proteins associated with a special pair of chlorophyll a molecules and a primary electron acceptor. Located centrally in a photosystem, this complex triggers the light reactions of photosynthesis. Excited by light energy, the pair of chlorophylls donates an electron to the primary electron acceptor, which passes an electron to an electron transport chain. | 23 | |
| 1889713681 | heterotroph | An organism that obtains organic food molecules by eating other organisms or substances derived from them | 24 | |
| 1889713682 | mesophyll | Leaf cells specialized for photosynthesis. In C3 and CAM plants, mesophyll cells are located between the upper and lower epidermis; in C4 plants, they are located between the bundle-sheath cells and the epidermis | 25 | |
| 1889713683 | stomata | A microscopic pore surrounded by guard cells in the epidermis of leaves and stems that allows gas exchange between the environment and the interior of the plant. | 26 | |
| 1889713684 | Photophosphorylation | The process of generating ATP from ADP and phosphate by means of chemiosmosis, using a proton-motive force generated across the thylakoid membrane of the chloroplast or the membrane of certain prokaryotes during the light reactions of photosynthesis. | 27 | |
| 1889713685 | carbon fixation | the initial incorporation of carbon from CO2 into an organic compound by an autotrophic organism (a plant, or another photosynthetic organism, or a chemoautotrophic prokaryote) | 28 | |
| 1889713686 | carotenoid | An accessory pigment, either yellow or orange, in the chloroplasts of plants and in some prokaryotes. By absorbing wavelengths of light that chlorophyll cannot, __________s broaden the spectrum of colors that can drive photosynthesis | 29 | |
| 1889713687 | glyceraldehyde 3-phosphate | (G3P) A three-carbon carbohydrate that is the direct product of the Calvin cycle, it is also an intermediate in glycolysis | 30 | |
| 1889713688 | RuBP | Rubisco, carboxylase-oxygenase, the enzyme that normally catalyzes the first step of the Calvin cycle (the addition of CO2 to _____). When excess O2 is present or CO2 levels are low, rubisco can bind oxygen, resulting in photorespiration | 31 | |
| 1889713689 | PEP carboxylase | An enzyme that adds CO2 to phosphoenolpyruvate (PEP) to form oxaloacetate in mesophyll cells of C4 plants. It acts prior to photosynthesis | 32 | |
| 1889713690 | photoautotroph | An organism that harnesses light energy to drive the synthesis of organic compounds from carbon dioxide | 33 |
