BIOL 209 1st Edition Lecture 11Outline of Last Lecture I. EnzymesII. Energy AcquisitionIII. Oxidation/Reduction ReactionsIV. Glycolysis Outline of Current Lecture I. FermentationII. RespirationIII. Krebs CycleIV. Question/Answer’sCurrent LectureI. FermentationA. Fermentation is relatively inefficient - only 2 ATP molecules generated for each glucose molecule catabolizedB. The ability of bacterial species to grow on a particular carbon source by fermentation depends upon having the correct enzymes 1. Fermentation of a particular carbon source can be used to distinguish species2. pH-sensitive dyes are used to indicate the ability of bacteria to ferment a givencarbon sourceII. RespirationA. Generates about 38 ATP/glucose1. Most efficient approach of energy generationB. ATP generation during respiration is based primarily on using the energy of electrons collected by the NAD and FAD (flavin adenine dinucleotide) electron carriers during the oxidation of glucoseC. The difference in energy between electrons bound to NADH, and electrons bound to oxygen (in water), is used to generate ATP 1. Known as oxidative phosphorylationD. Electrons are transfered from NADH to a series of electron acceptors that use the energy of the electrons to pump protons out of the mitochondria, (or teh cell, in teh case of prokaryotes)1. The electron transport proteins are located in the inner mitochondrial membrane (eukaryotes), or cell membrane (prokaryotes)These 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.2. Protons re-enter the mitochondrial matrix via the ATP synthase enzyme which catalyzes the formation of ATP The flow of protons down their concentration gradient provides the energy for ATP productionIII. Krebs CycleA. The Krebs cycle provides starting molecules for biosynthesis, and energy for ATP generation in the form of high-energy electrons1. Entry step to Krebs cycle: pyruvate is oxidized, generating NADH, CO2, and a remaining acetyl group that is linked to Coenzyme Aa. Coenzyme A is a carrier for hydrocarbon molecules b. CoA is the means of entering processed fatty acids into the Krebs cycleB. Oxidation of intermediates in the Krebs cycle leads to CO2 generation and electron transfer1. Regeneration of a 4-carbon compound allows continuation of the cycle 2. Net result: one turn of the cycle produces three NADH, one GTP, and one FADH2, and releases two molecules of CO2IV. Question/Answer’s1. Do fermentation and respiration use the same amount of glucose to provide the necessary energy for growth? Fermentation uses more glucose (more substrate to generate the same amount of
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