Bios 208 1st Edition Lecture 18Outline of Last Lecture I. PeroxisomesII. Components of the CytoskeletonIII. MicrotubulesIV. Centrosomes and CentriolesV. Cilia and FlagellaVI. Microfilaments (Actin Filaments)VII. Cell Walls of PlantsVIII. The Extracellular Matrix (ECM) of Animal CellsIX. Cell JunctionsX. Plasmodesmata in Plant CellsOutline of Current Lecture I. RespirationII. Redox Reactions: Oxidation and ReductionIII. The Stages of Cellular RespirationIV. Ox-Phos (Oxidative Phosphorylation)V. GlycolysisCurrent LectureI. RespirationA. Living cells require energy from outside sourcesB. Some animals,(e.g. primates), obtain energy by eating plants, and some animals feed on other organisms that eat plantsC. Energy flows into an ecosystem as sunlight and leaves as heatD. Photosynthesis generates O2 and organic molecules, which are used in cellular respirationThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.E. Cells use chemical energy stored in organic molecules to regenerate ATP, which powers workF. Several processes are central to cellular respiration and related pathways…glycolysis, Krebs cycle, electron transport.G. The breakdown of organic molecules is exergonicH. Fermentation is a partial degradation of sugars that occurs without O2 produces ethanol or lactic acid.I. Aerobic respiration consumes organic molecules and O2 and yields ATP…produces CO2J. Anaerobic respiration is similar to aerobic respiration but consumes compounds other than O2K. Cellular respiration includes both aerobic and anaerobic respiration but is often used to refer to aerobic respirationL. Although carbohydrates, fats, and proteins are all consumed as fuel, it is helpful to trace cellular respiration with the sugar glucoseM. C6H12O6 + 6 O2 6 CO2 + 6 H2O + Energy (ATP + heat)N. Energy is needed for motility, solute transport, chemical reactions, among others.O. The target is “energized” by the temporary attachment of a phosphate group (phosphorylation).P. Removing the phosphate (dephosphorylation) releases the E needed for the reactionII. Redox Reactions: Oxidation and ReductionA. The transfer of electrons during chemical reactions releases energy stored in organic moleculesB. This released energy is ultimately used to synthesize ATPC. Chemical reactions that transfer electrons between reactants are called oxidation-reduction reactions, or redox reactionsD. In oxidation, a substance loses electrons, or is oxidizedE. In reduction, a substance gains electrons, or is reduced (the amount of positive charge is reduced)F. The electron donor is called the reducing agentG. The electron receptor is called the oxidizing agentH. Some redox reactions do not transfer electrons but change the electron sharing in covalent I. An example is the reaction between methane and O2III. The Stages of Cellular RespirationA. Harvesting of energy from glucose has three stages:B. Glycolysis (breaks down glucose into two molecules of pyruvate).C. The citric acid cycle (completes the breakdown of glucose)D. Oxidative phosphorylation (accounts for most of the ATP synthesis)E. The process that generates most of the ATP is called oxidative phosphorylation because it is powered by redox reactionsIV. Ox-Phos (Oxidative Phosphorylation)A. Requires:a) reducing powerb) proton gradientc) electron transport chain (ETC)d) oxygene) many other factors…mitochondriaB. Basic structural features:a) Inner membrane contains an ETC infoldings are cristaeb) Outer membranec) Matrix (from cytoplasm of bacterial cell): contains ribosomes, DNA, Krebs cycle enzymesV. GlycolysisA. “Sugar breaking”B. Occurs in virtually all prok. and euk. cells (evolved early).C. Does not require O2; is not inhibited by O2D. Pathway of 10 reactions; soluble enzymes in cytosolE. Net of 2 ATP made by SLP (first half uses 2 ATP, second half makes 4F. ATP)G. NAD+ is a reactant, NADH is a
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