front 1 metabolism | back 1 all chemical reactions and physical workings of the cell collects and spends energy in the form of ATP or heat |
front 2 anabolism | back 2 biosynthesis of cell molecules and structures, requires energy input |
front 3 catabolism | back 3 break the bonds of larger molecules, release energy |
front 4 catalysts | back 4 speed up the rate of a chemical reaction without becoming part of the products or being consumed in the reaction |
front 5 enzymes overcome activation energy allowing the reaction to proceed by | back 5 increasing thermal energy to increase the velocity of molecules increasing the concentration of reactants to increase the rate of molecular collisions adding a catalyst |
front 6 enzyme characteristics checklist | back 6 most composed of protein and may require cofactors act as organic catalysts to speed up the rate of cellular reactions lower the activation energy required for a chemical reaction to proceed have unique characteristics such as shape, specificity, and function enable metabolic reactions to proceed at a speed compatible with life |
front 7 substrates | back 7 reactant molecules upon which enzymes act |
front 8 simple enzymes | back 8 consist of protein alone |
front 9 conjugated enzymes | back 9 contain protein and some other nonprotein molecule |
front 10 holoenzymes | back 10 whole conjugated enzymes |
front 11 apoenzyme | back 11 protein portion of holoenzyme |
front 12 cofactor | back 12 nonprotein protein of holoenzyme can be organic or inorganic |
front 13 active site or catalytic site | back 13 actual site where the substrate binds three-dimensional crevice or groove formed by the way amino acid chains are folded |
front 14 each enzyme has a different | back 14 primary structure, variation in folding, unique active site |
front 15 metallic cofactors | back 15 iron, copper, magnesium, manganese, zinc, cobalt, selenium, etc. assist with precise functions between enzyme and substrate |
front 16 coenzymes | back 16 organic compounds that work with apoenzyme to alter substrate remove chemical group from one substrate and add it to another substrate |
front 17 vitamins are an important component of | back 17 coenzymes |
front 18 oxidation | back 18 loss of electrons a compound that loses electrons is oxidized |
front 19 reduction | back 19 gain of electrons a compound that gains electrons is reduced |
front 20 two examples of coenzyme carriers | back 20 NAD and FAD |
front 21 exoenzymes | back 21 transported extracellularly break down large food molecules or harmful chemicals |
front 22 endoenzymes | back 22 retained intracellularly and function there most enzymes of metabolic pathways |
front 23 constitutive enzymes | back 23 always present in relatively constant amounts, regardless of the cellular environment |
front 24 regulated enzymes | back 24 production is turned on (induced) or turned off (repressed) in response to changes in concentration of substrate |
front 25 denaturation | back 25 weak bonds that maintain the shape of an apoenzyme are broken by heat, low or high pH, or certain chemicals, distorts shape and prevent substrate attachment |
front 26 competitive inhibition | back 26 a molecule that resembles the substrate occupies the active site, preventing the substrate from binding enzymes cannot act on the inhibitor and is effectively shut down |
front 27 noncompetitive inhibition | back 27 some enzymes have two binding sites - the active site and the regulatory site regulated by the binding of molecules other than the substrate to the regulatory site |
front 28 enzyme repression | back 28 stops further synthesis of an enzyme somewhere along its pathway |
front 29 enzyme induction | back 29 enzymes appear (are induced) only when suitable substrates are present |
front 30 exergonic reactions | back 30 release energy as they go forward energy is available for doing cellular work |
front 31 endergonic reactions | back 31 require the addition of energy to move forward |
front 32 the removal of hydrogens from a compound during a redox reaction is called | back 32 dehydrogenation |
front 33 NAD | back 33 most common electron carrier carries hydrogens and a pair of electrons from dehydrogenation reactions reduced NAD is presented as NADH + H+ or NADH |
front 34 FAD | back 34 reduced FAD is presented as FADH |
front 35 NADP | back 35 NAD phosphate |
front 36 catabolic pathways | back 36 electrons are extracted and carried through a series of of redox reactions to a final electron acceptor |
front 37 aerobic metabolism | back 37 oxygen is the final electron acceptor |
front 38 anaerobic metabolism | back 38 some other inorganic or organic compound is the final electron acceptor (not oxygen) |
front 39 adenosine triphosphate | back 39 three-part molecule adenine, ribose, three phosphate groups bonded to the ribose |
front 40 adenine | back 40 nitrogen base |
front 41 ribose | back 41 5 carbon sugar |
front 42 three phosphate groups bonded to ribose on ATP | back 42 bulky and negative, repelling electrostatic charges imposes a strain between the last two phosphate groups, removal of phosphates releases free energy |
front 43 ATP | back 43 primary energy currency of the cell it must be replaced, ongoing cycle |
front 44 substrate-level phsophorylation | back 44 generation of ATP through a transfer of phosphate group from a phosphorylated compound directly to ADP |
front 45 oxidative phosphorylation | back 45 a series of redox reactions occurring during the final phase of the respiratory pathway |
front 46 photophosphorylation | back 46 ATP formed through a series of sunlight-driven reactions in phototrophs |
front 47 three basic catabolic pathways | back 47 aerobic respiration, anaerobic respiration, fermentation |
front 48 glycoysis | back 48 most common pathway used to break down glucose |
front 49 fermentation pathway | back 49 facultative and aerotolerant anaerobes uses only glycolysis oxygen not required and use organic compounds as electron acceptors |
front 50 aerobic respiration | back 50 a series of enzyme-catalyzed reaction principal energy-yielding scheme for aerobic heterotrophs provides ATP and metabolic intermediates for other pathways |
front 51 glycolysis | back 51 glucose is enzymatically converted to pyruvic acid may be the first phase of aerobic respiration or the primary metabolic pathway synthesizes a small amount of ATP anaerobically pyruvic acid is essential intermediary metabolite |
front 52 pyruvic acid | back 52 a central metabolite used in several pathways by many organisms |
front 53 pyruvic acids in strict aerobes (and some anaerobes) | back 53 sent to the Krebs cycle |
front 54 pyruvic acid in facultative anaerobes | back 54 re-reduced into acids or other products |
front 55 the Krebs cycle | back 55 pyruvic acid into acetyl coenzyme A oxidation releases first CO2 enzymes and coenzyme A dehydrogenate pyruvic acid to a 2-carbon acetyl group NAD reduced to NADH NADH is shuttled to ETC to produce ATP |
front 56 how many times does the Krebs cycle happen | back 56 twice |
front 57 Krebs cycle purpose | back 57 transfer energy stored in acetyl CoA to NAD+ and FAD by reducing them |
front 58 main products of the Krebs cycle | back 58 reduced NADH and FADH2 two ATP produced through substrate-level phosphorylation |
front 59 electron transport system | back 59 chain of special redox carriers that receives electrons from NADH and FADH2 electrons are passed sequentially from one redox molecule to the next flow of electrons allows the active transport of hydrogens outside the cell membrane oxygen receives hydrogesn and electrons and produces water |
front 60 energy cascade sequence | back 60 NADH dehydrogenase FMN coenzyme Q cytochrome b cytochrome c1 cytochrome c cytochromes a and a3 |
front 61 ATP synthase | back 61 stationed along the membrane in close association with the ETS carriers captures released energy from the ETS carriers |
front 62 oxidative phosphorylation | back 62 the coupling of ATP synthesis to electron transport each NADH that enters the ETS gives rise to three ATP molecules NAD and FMN enter the ETS at a different point, so there is less energy released, and only give rise to two ATP molecules |
front 63 chemiosmosis | back 63 as the electron transport carriers shuttle electrons, hydrogen ions are actively pumped into the periplasmic space or the space between the cell wall and the cytoplasmic membrane this sets up a concentration gradient of hydrogen ions called the proton motive force |
front 64 proton motive force | back 64 consists of a difference in charge between the outside of the membrane (+) and the inside (-) separation of charges temporarily stores potential energy H+ can only diffuse into the membrane through ATP synthase, which sets the stage for ATP synthesis |
front 65 aerobic respiration ATP production | back 65 total possible ATP is 40, but only keep at most 38 because must expended 2 4 from glycolysis 2 from krebs 34 from ETC |
front 66 non ATP products of respiration | back 66 6 CO2 (Krebs) 6 O2 (consumed during ETC) 6 H2O (produced during ETC) 2 H2O (glycolysis) but 2 used in Krebs |
front 67 anaerobic respiration: nitrate and nitrite reduction systems | back 67 found in E. coli nitrate reductase catalyzes the removal of oxygen from nitrate reducing it to nitrite and water |
front 68 alcoholic fermentation | back 68 occurs in yeast or bacteria species that have metabolic pathways for converting pyruvic acid to ethanol decarboxylation of pyruvic acid to acetaldehyde reduction of acetaldehyde to ethanol |
front 69 homolactic fermentation | back 69 lactic acid bacteria reduce pyruvate to lactic acid mainly |
front 70 heterolactic fermenation | back 70 glucose is fermented to a mixture of lactic acid, acetic acid, and carbon dioxide |
front 71 mixed acid fermentation | back 71 members of the family enterobacteriaceae possess enzyme systems for converting pyruvic acid to several acids simultaneously acetic, lactic, succinic, formic acids, as well as CO2 accounts for accumulation of some types of gas in the intestine |
front 72 lipases | back 72 break apart fatty acids joined to glycerol which is converted to dihydroxyacetone phosphate which can enter step 4 of glycolysis |
front 73 beta oxidation | back 73 oxidation of fatty acids 2-carbon units transferred to coenzyme A, creating acetyl CoA (Krebs) oxidation of 6-carbon fatty acid yields 50 ATP, compared to 38 for a 6-carbon sugar |
front 74 proteases | back 74 break down proteins to their amino acid components amino groups removed through deamination remaining carbon compound can easily converted to Krebs cycle intermediate |
front 75 amphilbolism | back 75 most catabolic pathways contain strategic molecular intermediates that can be diverted into anabolic pathways a given molecule can serve multiple purposes to derive maximum benefit from all nutrient and metabolites catabolic and anabolic pathway are integrated to improve cell efficiency |
front 76 precursor molecule | back 76 a compound that is the source of another compound |
front 77 pyruvate as a precursor | back 77 provides intermediates for amino acids |
front 78 gluconeogenesis | back 78 pyruvate is a starting point for glucose synthesis in the event of inadequate glucose supply |
front 79 acetyl CoA as a precursor | back 79 can be converted into one of several amino acids can be condensed into hydrocarbon chains for fatty acid and lipid synthesis |
front 80 precursors to DNA and RNA | back 80 pathways that synthesize purines and pyrimidines originate in amino acids can be dependent on intermediates from the Krebs cycle |
front 81 carbohydrate biosynthesis | back 81 crucial role of glucose in metabolism and energy utilization major component of cellulose cell walls and storage granules glucose-6-P used to form glycogen |
front 82 proteins | back 82 large proportion of cell's contents essential components of enzymes, cytoplasmic membrane, cell wall, and cell appendages twenty amino acids are needed to make these proteins |
front 83 light-dependent reactions | back 83 proceed only in the presence of sunlight catabolic, energy-producing reactions |
front 84 light-independent reactions | back 84 proceed regardless of the lighting conditions anabolic, synthetic reactions carbon atoms from CO2 are added to the carbon backbones of organic molecules |
front 85 the calvin cycle | back 85 occurs in the chloroplast stroma or the cytoplasm of cyanobacteria use energy produced in the light phase to synthesize glucose |
front 86 oxygenic photosynthesis | back 86 dominant type on earth occurs in plants, algae, and cyanobacteria |
front 87 anoxygenic photosynthesis | back 87 occurs in green and purple bacteria that utilize bacteriochlorophyll have only cycling photosystem I generate a small amount of ATP use H2, H2S many are strict anaerobes |