BIOL 2050 1nd Edition Lecture 13 Outline of Last Lecture I. MetabolismII. Energya. Orderb. Energy and MetabolismIII. Enzymesa. RegulationOutline of Current Lecture II. Catabolic Processesa. Cellular Respirationi. Glycolysisii. Citric Acid Cycleiii. Oxidative PhosphorylationCurrent Lecture- Living cells require energy from outside sources- Photosynthesis generates oxygen and organic molecules, which are then used in cellular respirationCatabolic ProcessesI. Fermentation: partial degradation of sugars that occur without oxygenII. Aerobic Respiration: consumes organic molecules and oxygen and produces ATPIII. Anaerobic Respiration: consumes compounds other than oxygenIV. Cellular Respiration: includes both aerobic and anaerobic respirationa. Cellular respiration is traced by the sugar GlucoseV. Redox Reactions: chemical reactions that transfer electrons between reactants a. Oxidation: when a substance loses electronsb. Reduction: substance gains electronsc. Reducing Agent: electron donord. Oxidizing Agent: electron receptorCellular Respiration-glucose and other organic molecules are broken down in a series of steps.- Electrons from organic compounds are usually first transferred to NAD+, a coenzyme.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.-NADH passes electrons to the electron transport chainStages:I. Glycolysis: breaks down glucose into two molecules of pyruvatea. Occurs in the cytoplasmb. Occurs whether oxygen is present or notc. Also generates 4ATP but uses two in the processd. Substrate-level phosphorylation: a smaller amount of ATP is formed II. Oxidation of Pyruvatea. Before the citric acid cycle, pyruvate must be converted to acetyl coenzyme Ab. Links glycolysis to the citric acid cycleIII. Calvin Cyclea. Completes the breakdown of pyruvate to CO2b. Generates 1 ATP, 3 NADH, and 1 FADH2c. Has eight steps each using a specific enzymeIV. Oxidative Phosphorylationa. NADH and FADH2 donates electrons to the electron transport chain, which powers ATP synthesisb. Electron Transport Chain: in the inner membrane of the mitochondriai. Electrons drop free energy as they go down the chain and finally passed O2 to form H2O.ii. No ATP is generatedc. Chemiosmosis: the use of energy in a H+ gradient to drive cellular worki. Electron transfer in the electron transfer chain causes proteins to pump H+ into the intermembrane spaceii. H+ then moves back across the membrane passing through the proton, ATP synthase1. Uses exergonic flow of H+ to drive phosphorylation of ATPd. Generates 90% of
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