Term
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Definition
| A catabolic process that makes a limited amount of ATP from glucose without an electron transport chain and that produces a characteristic end product, such as ethyl alcohol or lactic acid |
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Term
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Definition
| A catabolic pathway for organic molecules, using oxygen as the final electron acceptor in an electron transport chain and ultimately producing ATP. This is the most efficient catabolic pathway and is carried out in most eukaryotic cells and many prokaryotic organisms. |
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Definition
| The catabolic pathways of erobic and anaerobic respiration, which break down organic molecules and use an electron transport chain for the production of ATP. |
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Term
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Definition
| A chemical reaction involving the comlete or partial transfer of one or more electrons from one reactant to another; short for reduction-oxidation reaction. |
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Definition
| The complete or partial loss of electrons from a substance involved in a redoxreaction. |
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Term
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Definition
| The complete or partial addition of electrons to a substance involved in a redox reaction. |
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Term
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Definition
| The electron donor in a redox reaction. |
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Term
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Definition
| The electron acceptor in a redox reaction. |
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Term
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Definition
| Nicotinamide adenine dinucleotide, a coenzyme that cycles easily between oxidized and reduced states, thus acting as an electron carrier. |
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Term
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Definition
| A sequence of elecrton carrier molecules that shuttle electrons down a series of redox reactions that release energy used to make ATP. |
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Definition
| A series of reactions that ultimately splits glucose into pyruvate. Glycolysis occurs in almost all living cells, serving as the starting point for fermentation or cellular respiration. |
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Term
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Definition
| A chemical cycle involving eight steps that completes the metabolic breakdown of glucose molecules begun in glycolysis by oxidizing acetyl CoA to carbon dioxide; occurs within the mitochondrion ineukaryotic cells and in the cytosol of prokaryotes; together with pyruvate oxidation, the second major stage in cellular respiration. |
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Term
| Oxidative Phosphorylation |
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Definition
| The production of ATP using energy derived from the redox reactions of an electrontransport chain; the third major stage of cellular respiration. |
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Term
| Substrate-level Phosphorylation |
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Definition
| The enzyme-catalyzed formation of ATP by direct transfer of a phosphate group to ADP from an intermediate substrate in catabolism. |
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Term
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Definition
| Acetyl coenzyme A; the entry compound for the citric acid cycle in cellular respiration, formed from a fragment of pyruvate attached to a coenzyme. |
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Term
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Definition
| An iron-containing protein that is a component of electron transport chains in the mitochondria and chloroplasts of eukaryotic cells and the plasma membranes of prokaryotic cells. |
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Definition
| A complex of several membrane proteins that functions in chemiosmosis with adjacent electron transport chains, using the energy or a hydrogen ion (protons) concentration gradient to make ATP. ATP Synthases are found in the inner mitochondrial membranes of eukaryotic cells and in the plasma membranes of prokaryotes. |
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Term
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Definition
| An energy-coupling mechanism that uses energy stored in the form of a hydrogen ion gradient across a membrane to drive cellular work, such as the synthesis of ATP. Under aerobic conditions, most ATP synthesis in cells occurs by chemiosmosis. |
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Definition
| The potential energy stored in the form of a proton electrochemical gradient, generated by the pumping of hydrogen ions across a biological membrane during chemiosmosis. |
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Term
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Definition
| Glycolysis followed by the reduction of pyruvate to ethyl alcohol, regenerating NAD+ and releasing carbon dioxide. |
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Term
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Definition
| Glycolysis followed by the reduction of pyruvate to lactate, regenerating NAD+ with no release of carbon dioxide. |
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Term
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Definition
| An organism that only carries out fermentation or anaerobic respiration. Such organisms cannot use exygen and in fact may be poisoned by it. |
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Term
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Definition
| An organism that makes ATP by aerobic respiration if oxygen is present but that switches to anaerobic respiration or fermentation if oxygen is not present. |
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Term
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Definition
| A metabolic sequence that breaks fatty acids down to two-carbon fragments that enter the citric acid cycle as acetyl CoA. |
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Definition
| The conversion of light energy to chemical energy that is stored in sugars or other organic compounds; occurs in plants, algae, and certain prokaryotes. |
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Definition
| An organism that obtains organic food molecules without eating other organisms or substances derived from other organisms. Autotrophs use energy from the sun or from oxidation of inorganic substances to make organic molecules from inorganic ones. |
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Term
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Definition
| An organism that obtains organic food molecules by eating other organisms or substances derived from them. |
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Term
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Definition
| Leaf cells specialized for photosynthesis. In C, and CAM plants mesophyll cells are located between the upper and lower epidermis; in C plants they are located between the bundle-sheath cells and the epidermis. |
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Term
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Definition
| The dense fluid within the chiroplast surrounding the thylakoid membrane and containing ribosomes and DNA; involved in the synthesis of organic molecules from carbondioxide and water. |
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Term
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Definition
| A flattened, membranous sac inside a chloroplast. Thlyakoids often exist in stacks called grana that are interconnected; their membranes contain molecular "machinery" used to convert light energy to chemical energy. |
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Term
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Definition
| A green pigment located in membranes within the chloroplasts of plants and algae and in the membranes of certain prokaryotes. Chlorophyll a participates directly in the light reactions, which convert solar energy to chemical energy. |
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Term
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Definition
| The first of two major stages in photosynthesis. 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. |
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Definition
| The second of two major stages in photosynthesis involving fixation of atmospheric CO2 and reduction of the fixed carbon into carbohydrate. |
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Term
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Definition
| Nocotinamide adenine dinucleotide phosphate, an electron acceptor that, as NADPH, temporarily stores energized electrons produced during the light reactions. |
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Term
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Definition
| 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. |
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Term
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Definition
| The initial incorporation of carbon from CO2 into an organic compound by an autotrophic organism. |
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Term
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Definition
| The distance between crests of waves, such as those of the electromagnetic spectrum. |
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Term
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Definition
| The entire spectrum of electromagnetic radiation, ranging in wavelength from less than a nanometer to more than a kilometer. |
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Term
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Definition
| That portion of the electromagnetic spectrum that can be detected as various colors by the human eye, ranging in wavelength from about 380 nm to about 750 nm. |
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Term
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Definition
| A quantum, or discrete quantity, of light energy that begaves as if it were a particle. |
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Term
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Definition
| An instrumentn that measures the proportions of light of different wavelengths absorbed and transmitted by a pigment solution. |
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Term
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Definition
| The range of a pigment's ability to absorb various wavelenths of light; also a graph of such a range. |
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Term
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Definition
| A photosynthetic pigment that participates directly in the lighth reactions, which convert solar energy to chemical energy. |
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Term
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Definition
| A graph that profiles the relative effectiveness of different wavelengths of radiation in driving a particular process. |
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Term
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Definition
| An accessory photosynthetic pigment that transfers energy to chlorophyll a |
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Term
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Definition
| An accessory pigment, either yellow or orange, in the chloroplasts of plants and in some prokaryotes. By absorbing wavelengths of light that chlorophyll cannot, carotenoids broaden the spectrum of colors that can drive photosynthesis. |
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Term
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Definition
| A light-capturing unit located in the thylakoid membrane of the chloroplast or in the membrane of some prokaryotes, consisting of a reaction-center complex surrounded by numerous light-harvesting complexes. These are two types of photosystems, I and II; they absorb light best at different wavelengths. |
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Term
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Definition
| 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. |
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Term
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Definition
| A complex of proteins associated with pigment molecules that captures light energy and transfers it to reaction-center pigments in a photostream. |
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Term
| Primary Electron Acceptor |
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Definition
| In the thylakoid membrane of a chloroplast or in the membrane of some prokaryotes, a specialized molecule that shares the reaction-center complex witha pair of chlorophyll a molecules and that accepts an electron from them. |
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Term
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Definition
| 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. |
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Term
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Definition
| 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. |
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Term
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Definition
| A route of electron flow during the light reactions of photosynthesis that involves only photosystem I and that produces ATP but nod NADPH or O2. |
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Term
| Glyceraldehyde 3-Phosphate (G3P) |
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Definition
| A three-carbon carbohydrate that is the direct product of the calvin cycle; it is also an intermediate in glycolysis. |
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Term
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Definition
| Ribulose bisphosphate (RuBP) carboxylase, the enzyme that catalyzes the first step of the Calvin cycle (the addition of CO2 to RuBP) |
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Term
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Definition
| A plant that uses the Calvin cycle for the initial steps that incorporate CO2 into organic material, forming a three-carbon compound as the first stable intermediate. |
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Term
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Definition
| 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. |
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Term
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Definition
| The reproduction of cells. |
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Term
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Definition
| An ordered sequence of events in the life of a cell, from its origin in the division of a parent cell until its own division into two. The eukaryotic cell cycle is composed of interphase and M phase. |
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Term
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Definition
| The genetic material of an organism or virus; the complete complement of an organism's or virus's genes along with its noncoding nucleic acid sequences. |
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Term
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Definition
| A cellular structure carrying genetic material, found in the nucleus of eukaryotic cells. Each chromosome consists of one very long DNA molecule and associated proteins. |
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Term
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Definition
| The complex of DNA and proteins that makes up eukaryotic chromosomes. When the cell is not dividing, chromatin exists in its dispersed form, as a mass of very long, thin fibers that are not visible with a light microscope. |
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Term
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Definition
| Any cell in a multicellular organism except a sperm or egg or their precursors. |
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Term
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Definition
| A haploid reproductive cell, such as an egg or sperm. Gametes unite during sexual reproduction to produce a diploid zygote. |
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Term
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Definition
| Two copies of a duplicated chromosome attached to each other by proteins at the centromere and, sometimes, along the arms. While joined, two sister chromatids make up one chromosome. Chromatids are eventually separated during mitosis or meiosis II. |
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Term
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Definition
| In a duplicated chromosome, the region on each sister chromatid where they are most closely attached to each other by proteins that bind to specific DNA sequences; this close attachment cuases a constriction in the condensed chromosome. |
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Term
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Definition
| A process of nuclear division in eukaryotic cells conventionally divided into five stages: prophase, prometaphase, metaphase, anaphase, and telophase. Mitosis conserves chromosome number by allocating replicated chromosomes equally to each of the daughter nuclei. |
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Term
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Definition
| The division of the cytoplasm to form two separate daugter cells immediately after mitosis, meiosis I, or meisis II. |
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Term
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Definition
| The phase of the cell cycle that includes mitosis and cytokinesis. |
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Term
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Definition
| The period in the cell cycle when the cell is not divising. During interphase, cellular metabolic activity is high, chromosomes and organelles are duplicated, and cell size may increase. Interphase often accounts for about 90% of the cell cycle. |
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Term
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Definition
| The first gap, or growth phase, of the cell cycle, consisting of the portion of interphase before DNA synthesis begins. |
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Term
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Definition
| The synthesis phase of the cell cycle; the portion of interphase during which DNA is replicated. |
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Term
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Definition
| The second gap, or growth phase, of the cell cycle, consisting of the portion of interphase after DNA synthesis occurs. |
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Term
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Definition
| The first stage of mitosis, in which the chromatin condenses into discrete chromosomes visile with a light microscope, the mitotic spindle begins to form, and the nucleolus disappears but the nucleus remains intact. |
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Term
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Definition
| The second stage of mitosis, in which the nuclear envelope fragments and the spindle microtubules attach to the kinetochores of the chromosomes. |
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Term
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Definition
| The third stage of mitosis, in which the spindle is complete and the chromosomes, attached to microtubules at their kinetochores, are all aligned at the metaphase plate. |
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Term
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Definition
| The fourth stage of mitosis, in which the chromatids of each chromosome have separated and the daughter chromosomes are moving the the poles of the cell. |
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Term
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Definition
| The fifth and final stage of mitosis, in which daughter nuclei are forming and cytokinesis has typically begun. |
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Term
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Definition
| An assemblage of microtubules and associated proteins that is involved in the movement of chromosomes during mitosis. |
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Term
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Definition
| A structure present in the cytoplasm of animal cells that functions as a microtubule-organizing center and is important during cell division. A centrosome has two centrioles. |
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Term
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Definition
| A radial array of short microtubules that extends from each centrosome toward the plasma membrane in an animal cell undergoing mitosis. |
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Term
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Definition
| A structure of proteins attached to the centromere that links each sister chromatid to the mitotic spindle. |
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Term
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Definition
| An imaginary structure located at a plane midway between the poles of a cell in metaphase on which the centromeres of all the duplicated chromosomes are located. |
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Term
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Definition
The process of cytokinesis in animal cells, characterized by pinching of the plasma membrane
The succession of rapid cell divisions without significant growth during early embryonic development that converts the zygote to a ball of cells. |
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Term
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Definition
| The first sign of cleavage in an animal cell; a shallow groove around the cell in the cell surface near the old metaphase plate. |
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Term
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Definition
| A membrane-bounded, flattened sac located at the midline of a dividing plant cell, inside which the new cell wall forms during cytokinesis. |
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Term
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Definition
| A method of asexual reproduction by "division in half." In prokaryotes, binary fission does not involve mitosis, but in single-celled eukaryotes that undergo binary fission, mitosis is part of the process. |
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Term
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Definition
| Site where the replication of a DNA molecule begins, consisting of a specific sequence of nucleotides. |
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Term
| Cell Cycle Control System |
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Definition
| A cyclically operating set of molecules in the eukaryotic cell that both triggers and coordinates key events in the cell cycle. |
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Term
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Definition
| A control point in the cell cycle where stop and go-ahead signals can regulate the cycle. |
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Term
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Definition
| A nondividing state occupied by cells that have left the cell cycle, sometimes reversibly. |
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Term
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Definition
| A cellular protein that occurs in a cyclically fluctuating concentration and that plays an important role in regulating the cell cycle. |
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Term
| Cyclin-Dependent Kinase (Cdk) |
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Definition
| A protein kinase that is active only when attached to a particular cyclin. |
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Term
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Definition
| Maturation-promoting factor; a protein complex required for a cell to progress from late interphase to mitosis. The active form consists of cyclin and a protein kinase. |
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Term
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Definition
A protein that must be present in the extracellular environment for the growth and normal development of certain types of cells.
A local regulator that acts on nearby cellsto stimulate cell proliferation and differentiation. |
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Term
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Definition
The conversion of a normal animal cell to a cancerous cell
A change in genotype and phenotype dur to the assimilation of external DNA by a cell. When the external DNA is from a member of a different species, transformation results in horizontal gene transfer. |
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Term
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Definition
| A mass of abnormal cells with specific genetic and cellular changes such that the cells rae not capable of surviving at a new site and generally remain at the site of the tumor's origin. |
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Term
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Definition
| A cancerous tumor containing cells that have significant genetic and cellular changes and are capable of invading and surviving in new site. Malignant tumors can impair the functionns of one or more organs. |
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Definition
| The spread of cancer cells to locations distant from their original site. |
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Definition
| The transmission of traits from one generation to the next. |
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Definition
| Differences between members of the same species. |
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Definition
| The scientific study of heredity and hereditary variation. |
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Term
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Definition
| A discrete unit of hereditay information consisting of a specific nucleotide sequence in DNA. |
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Definition
| A haploid reproductive cell, such as an egg or sperm. Gametes unite during sexual reproduction to produce a diploid zygote. |
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Term
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Definition
| Any cell in a multicellular organism except a sperm or egg or their precursors. |
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Term
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Definition
| A specific place along the length of a chromosome where a given gene is located. |
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Term
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Definition
| The generation of offspring from a single parent that occurs without the fusion of gametes. In most cases, the offspring are genetically identical to the parent. |
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Term
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Definition
A lineage of genetically identical individuals or cells
In popular usage, an individual that is genetically identical to another individual
As a verb, to make one or more genetic replicas of an individual or cell |
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Term
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Definition
| A type of reproduction in which two parents give rise to offspring that have unique combinations of genes inherited from both parents via the gametes. |
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Term
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Definition
| The generation-to-generation sequence of stages in the reproductive history of an organism. |
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Term
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Definition
| A display of the chromosome pairs of a cell arranged by size and shape. |
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Term
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Definition
| A pair of chromosomes of the same lenth, centromere position, and staining pattern that possess genes for the same characters at corresponding loci. One homologous chromosome is inherited from the organism's father, the other from the mother. |
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Definition
| A chromosome responsible for determining the sex of an individual. |
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Term
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Definition
| A chromosome that is not directly involved in determining sex; not a sex chromosome. |
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Term
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Definition
| A cell containing two sets of chromosomes (2n), one set inherited from each parent. |
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Definition
| A cell containing only one set of chromosomes. |
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Definition
The union of haploid gametes to produce a diploid zygote
The addition of mineral nutrients to the soil. |
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Term
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Definition
| The diploid cell produced by the union of haploid gametes during fertilization; a fertilized egg. |
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Term
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Definition
| A modified type of cell division in sexually reproducing organisms consistin of two rounds of cell division but only one round of DNA replication. It results in cells with half the number of chromosome sets as the original cell. |
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Term
| Alternation of Generations |
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Definition
| A life cycle in which there is both a multicellular diploid form, the sporophyte, and a multicellular haploid form, the gametophyte; characteristic of plants and some algae. |
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Term
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Definition
| The first division of a two-stage process of cell division in sexually reproducing organisms that results in cells with half the number of chromosome sets as the original cell. |
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Term
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Definition
| The second diision of a two-stage process of cell division in sexually reproducing prganisms that results in cells with half the number of chromosome sets as the original cells. |
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Term
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Definition
| A chromosome created when crossing over combined DNA from two parents into a single chromosome. |
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