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43 Cards in this Set
- Front
- Back
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Phototroph
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obtains energy from the sun and stores is as chemical energy
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Heterotroph
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uses organic carbon for growth
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Autotroph
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produces complex organic compounds from simple inorganic molecules using energy from light or inorganic chemical reactions
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Waste from
photosynthesis and heterotrophism |
Heat energy
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Central Biochemical Pathways used for both Catabolism and Anabolism
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(1) glycolysis
(2) TCA cycle (3) Pentose phosphate shunt |
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Major Source for Producing Energy in cell
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electron transfer
>requires electron donor and acceptor |
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In which cells does electron transport occur?
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ALL cells, from bacteria to humans (difference donors and acceptors)
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Phosphorylation Energy
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(1) less energy then redox reactions (electron transfer)
(2) no e- donor or acceptor needed (3) phosphate added via dehydration; released via hydrolysis (4) ATP (or GTP, less common) |
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Activation Energy
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energy required to bring all molecules in a chemical reaction into a reactive state
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Enzymes
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catalytic proteins
speed up rxns by lowering activation energy VERY SPECIFIC for substrate (Ex. cellulose vs. starch) |
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Active Site
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portion of enzyme where substrate binds
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Aldolase
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fructose-1,6-bisphosphate
TO glyceraldehyde-3-phosphate AND dihydroxyacetone phosphate |
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Molecules that can help in catalysis
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(1) Enzymes
(2) Prosthetic Groups (3) Coenzymes |
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Prosthetic Groups
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Can help in catalysis
Usually covalently and permanently bound to enzymes |
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Coenzymes
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Can help in catalysis
>loosely bound >can associate with different enzymes > often vitamin derivatives (NAD+, niacin) |
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Electron Donors and Receptors Categories
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Electron donor
Lithotrophy: inorganic molecule Organotrophy: organic molecule Electron acceptor Respiration: inorganic molecules Fermentation: organic molecules |
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Oxidation-reduction (redox) reaction
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> transfer e- from donor to acceptor
e- donor: oxidized e- acceptor: reduced |
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Redox Electron Carrier
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(1) membrane bound (Ex: prosthetic groups like cytochrome c)
(2) freely diffusible (Ex. coenzymes like NAD+ and NADP+) |
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Difference between NAD+ and NADP+
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NAD+/NADH = catabolism
NADP+/NADPH = anabolism |
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Fermentation vs. Respiration
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Similarities
> used by chemoorganotrophs > ATP synthesized through redox rxn Differences > F: no exogenous e- acceptor > R: O2 or terminal e- acceptor > F: substrate-level phosphorylation > R: substrate-level phosphorylation AND oxidative phosphorylation |
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Substrate-level Phosphorylation
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a phosphate group is added to an intermediate and eventually transferred to ADP to form ATP
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Oxidative Phosphorylation
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ATP synthesized by proton motive force (use of ATP synthase)
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Photophosphorylation
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similar to oxidative phosphorylation except light drives redox rxns to produce ETC
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Glycolysis
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(Embden-Meyerhof Pathway)
1 glucose TO 2 pyruvate 2 ATP 2 NADH |
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Precursor metabolites made in glycolysis
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6 precursors (used to make macromolecules in cell)
(1) G6P (2) F6P (3) G3P (4) 3-phosophgylcerate (5) PEP (6) pyruvate |
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ATP Production through
Fermentation vs. Respiration |
Fermentation: 2 ATP (those from glycolysis)
Respiration: 38 ATP |
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Two (2) Types of Fermentation
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(1) Homolactic (e- from NADH > pyruvate > lactic acid)
(2) Alcoholic (e- from NADH > pyruvate > ethanol + CO2) |
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Inorganic compounds that CAN be e- acceptor
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nitrate, ferric iron, sulfate, carbonate
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I singular abl.
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me
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Two (2) types of Photosynthesis
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(1) anoxygenic: no O2 produces (most bacteria)
(2) oxygenic: water split to produce O2 (cyanobacteria and plants) |
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Photosynthetic Pigments
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> Chlorophylls (oxygenic phototrophs)
> Bacteriochlorophylls (anoxygenic phototrophs) |
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Photosynthetic Membranes
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> Chloroplasts (eukaryotes): w/ photosynthetic thylakoid membranes
>CM in many bacteria >chlorosomes in green sulfur bacteria > thylakoid membrane in cyanobacteria |
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Antenna chlorophyll molecules
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harvest light energy and transfer it to reaction center where ATP production occurs
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Accessory Pigments for Photosynthesis
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(1) Carotenoids (also protect from oxidative damage)
(2) Phycobilins |
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Anoxygenic Phototrophs in Bacterial Phyla
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(1) Chloroflexus (green nonsulfur)
(2) Proteobacteria (purple sulfur and nonsulfur) (3) Chlorobium (green sulfur) (4) Heliobacteria (gram positive) (5) Rhodobacter: used to study- photosynthesis in light, respiration in dark, grown in presence and absence of O2 |
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Photosystems in Oxygenic Photosynthesis
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Photosystem I: resembles anoxygenic
Photosystem II: splits H20 to yield O2 |
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Calvin Cycle
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> CO2 fixation in autotrophs
CO2's + ribulose bisphosphate (RubisCo) === G3P -> F6P (into glycolysis) [carboxysomes store RubisCo) |
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Carboxysomes
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store RubisCo for use in the Calvin Cycle
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Reverse TCA and Hydroxypropionate Cycle
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Reverse TCA: green sulfur bacteria
Hydroxypropionate Cycle: Chloroflexus (oldest anoxygenic phototrophic bacteria) |
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Chemolithotrophy
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oxidize inorganic chemicals as their sole source of energy
> mostly autotrophs, some mixotrophs > O2 usually terminal e- acceptor Inorganic compounds used: hydrogen sulfide, hydrogen gas, ferrous iron, and ammonia as e- donors |
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Four (4) Types of Chemolitotrophy
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(1) Hydrogen Oxidation (autotrophs; Calvin Cycle; aerobic): most use organic compounds if available
(2) Sulfur Oxidation (autotrophs; Calvin Cycle; aerobic) (3) Iron Oxidation (obligately acidophilic) (4) Nitrification (heterotrophs, aerobic) |
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Three (3) Types of Anaerobic Respiration
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(1) Nitrate Reduction and Denitrification: Nitrate is e- acceptor
(Ex. Pseudomonas) (2) Sulfate Reduction: sulfate e- acceptor (3) Methanogenesis: inorganic N and S or CO2 or other act as e- acceptors (anaerobic Archaea) |
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Nitrogen Fixation
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> 40 ATP's for each N2 fixed
> enzyme complex: nitrogenase (inhibited by O2) TO PREVENT O2 interaction: > rapid removal by respiration > slime layers > compartmentalization (heterocysts) > symbionts within plants |
