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BIOL 101 1st Edition Lecture 11 Outline of Last Lecture Cell StructuresCell Wall (some)Extra Cellular MatrixIntercellular JunctionsPlantsPlasmdesmataAnimalsTight JunctionsDesmosomesGap JunctionsMembrane TransportPassive TransportDiffusionFacilitated TransportCarrier ProteinsActive TransportIon PumpsExocytosis and EndocytosisExocytosisEndocytosisPhagocytosisPinocytosisOutline of Current Lecture Metabolic PathwaysCatabolismAnabolismCells and the Flow of EnergyForms of EnergyKineticThermal (heat)LightPotentialChemicalLaws of energy TransformationTwo Laws of ThermodynamicsLaw of Conservation of EnergyEntropyThese 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.Free EnergyPortion of Energy that can do WorkOnly reactions with a -ΔG are spontaneous (decrease in free energy)These reactions can supply energy for cellular workMetabolic Reactions and Free EnergyChemical ReactionsExergonicEndergonicATP: Energy for CellsStructureCoupled ReactionsFunctions of ATPMetabolic Pathways and EnzymesEnzymesSubstrateActive SiteNamesEnergy of ActivationEnzyme-Substrate ComplexActive SiteSubstrate SpecificityFactors Affecting the Rate of Enzyme ReactionsSubstrate ConcentrationTemperature and pHEnzyme ConcentrationEnzyme inhibitionEnzyme Cofactors/CoenzymesRegulation of Enzymatic ActivityAllosteric RegulationActivationInhibitionCooperativityFeedback InhibitionCurrent LectureMetabolic pathways: Enzymes are proteins. The gene tells the enzyme what to do. Genetic mutations can block certain pathways. Our cells are always breaking things down and building things up. Energy is being able to do work. Kinetic energy is energy in motion. Potential energy is stored. Glucose is stored energy (30% efficient). Chemical energy is available for cells use.Thermodynamics means energy can be transferred and transformed but not created or destroyed. A lot of energy is lost as heat. Some energy is unusable. Metabolic reactions can be classifies as releasing energy (exergonic/ spontaneous reaction) or requiring energy (endergonic reaction). Making sugar is endergonic meaning it required energy. Glucose has free energy (G=-686 Kcal/mole). You get about 34 ATP per glucose molecules duringcellular respiration. Catabolic pathway. You need an input of energy to make proteins (anabolic pathway), Requires 686kcal/mole of glucose. Types of work that cells do: transport, chemical and mechanical. The hydrolysis of ATP to ADP isexergonic. You have about 50 paperclips worth of ATP in your body right now (50g)- not a lot. Adenosine Tri-phosphate has 3 phosphate groups, when H2O comes in and releases a phosphateit turns to Adenosine di-phosphate (exergonic), releases -.7.3 kcal/mole. Exergonic reactions make endergonic reactions possible. Your body makes ATP through cellular respiration (mitochondria). An average person makes and breaks their body weight in ATP a day (1025 ATP’s). If you didn’t make and break ATP you would wake up 200 pounds. How does ATP do its work? Couple molecules with ATP inside the enzyme with hydrolysis. Essentially you add a phosphate and make -7.3 kcal/mole of energy +3.4 kcal/mole to make -3.9 kcal/mole, this is a nonspontaneous reaction. Study figure 8.10. Enzymes lower the energy of activation for a catalytic reaction, could release or take energy. There are 6 categories of enzymes: Oxidoreductases, transferase, hydrolases, isomerases (rearranges atoms), ligases (joins) and lyases (double bonds). Dehydrogenases pull on two H at a time. Kinases transfer phosphates and decarboxylase removes carboxylic acids function groups. Hexokinase is the first molecule of glycolysis and works on 6 carbon sugars like glucose. It has an active site that will interact with 6-carbon sugars only. An inducted fit (ES) will occur like a handshake that will bend and twist and break covalent bonds. The product is glucose 6-phosphate. Glucose + ATP -> glucose-6-phophate (phosphorylated intermediate) + ADP. The substrate enters the active site, ES complex occurs. Study figure 8.14. They lower the energyof activation. A certain amount of free energy of the reactants and certain amount of free energy in the products. Only the energy of activation in effected, not the free energy (delta G). Enzymes and heat can break bonds. Every enzyme has optimal environments. Body temp is 37 degrees Celsius. Different enzymes work in different heat, pH’s and more. Different environments can start and stop enzymes from working. Cells can regulate enzymatic activity. If the cell wants a biochemical reaction to happen/ stop a reaction, there are inhibitor and activation molecules. Competitive inhibitors compete for the active site (blocks)- penicillin is a competitive inhibitor for cells to make cells walls. Pancreatic lipase breaks down lipids. Non-competitive inhibitors change the shape of the active sit but is not in the active


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