Exam 3 Study GuideChapter 8:Understand the difference between anabolic and catabolic pathwaysCatabolic pathways-involve the breaking down of large molecules, releases energyAnabolic pathways-involve building, requires energy, sometimes called biosynthetic pathwaysUnderstand the first 2 laws of thermodynamics and how they relate to energy exchangeFirst Law of Thermodynamics-energy can be transferred and transformed but it cannot be destroyed, principle of conservation of energySecond Law of Thermodynamics-any time energy is transformed, some of it is lost as heatKnow the Free Energy equation, and be able to calculate ΔGΔG=G(final products) – G(starting reactants)ΔG=change in free energyΔH=enthalapy/total energyT=temperatureΔS=change in entropyTΔS=energy not available to do workΔG= ΔH – TΔSΔG=0 -chemical equilibrium and no work can be done-# =energy was released during the reaction+# =energy was required for the reactionKnow the characteristics of endergonic and exergonic reactionsEndergonic- require the input of energy and have a positive ΔG number, they are energetically uphill, non-spontaneous reaction, products have more free energy than reactantsExergonic-release energy when they occur and have a negative ΔG, products have less free energy than the reactants, spontaneous reaction, energetically downhillUnderstand how ATP hydrolysis provides energy for endergonic reactionsExtremely exergonic reaction, it releases 7.3 kCal/Mol this energy must go somewhere so it is used to power an endergonic reactionATP + H₂O ADP + Pᵢ Pᵢ=inorganic phosphateUnderstand how enzymes catalyze chemical reactionsEnzymes catalyze reactions by lowering activation energy. This does not affect the free energy ofthe reactants or the productsUnderstand the different types of enzyme inhibitors and how they workCompetitive Inhibitors- compete with the substrate and actually bind to the active site of an enzyme reducing enzymatic activity, also called mimicsAllosteric Inhibitors- non-competitive, once a substrate binds to the allosteric site the enzyme is turned off even though the active sit is still open. Bind to a site on the enzyme separate from the active site. This causes a change in the shape of the active site, preventing the substrate from binding.Main difference is where they bind on the enzyme. Enzymes keep you from producing to much of something that could be harmful for the cellChapter 9:Understand what happens during redox reactionsRedox reactions(Oxidation-Reduction Reactions) involve transfer of electrons from one atom to another. The atom that loses and electron is oxidized, while the atom that receives the electron is reduced. Called reduction because the electrons are negative and total positive charge of an atom that receives an electron gets reduced. In order for one electron to be oxidized, another atom must be reduced and vice versa. Movement to a more electronegative atom is an exergonic reaction. Electrons get donated from a less electronegative atom to a more electronegative atom. This is a downhill reaction because it is natural. Potential energy gets released because the likelihood of the electron being taken from the larger atom is very low.Be able to define oxidizing and reducing agentsOxidizing agent receives an electron and allows another atom to be reducedReducing agent donates an electron and allows another atom to be oxidizedOxidation is a reaction with oxygenUnderstand what happens during fermentation, and why our cells perform this reactionThe body only performs fermentation when there is not enough oxygen to break down your food. There is not enough oxygen to perform cellular respiration so products from glycolysis(2 pyruvates) get reduced to regenerate NAD+, which is needed for glycolysis. This allows glycolysis to continue to produce ATP in the absence of oxygen. Our cells perform fermentation to regenerate NAD+ needed for glycolysis. Fermentation is not a part of cellular respiration.Understand what happens during glycolysis, the bridge reaction, Kreb’s cycle, and oxidative phosphorylation, including the inputs, outputs, location, and O2 requirementsGlycolysis-happens all the time in the cytoplasm-input=glucose(6 Carbon molecule)-output=2 pyruvate(3 Carbon molecules)-happens all the time-2 phases:-Energy Investment Phase- use some ATP to get more energy in the end-Energy Payoff (Energy-Yielding) Phase- glucose gets split, producing 4 ATP’sBridge Reaction-happens in the mitochondrial matrix, O₂ required from here on out, links glycolysis to Kreb’s cycle-input: 2 pyruvates-output: 2 acetyl CoA’s, 2 NADHKreb’s Cycle-O₂ required-input=2 acetyl CoA’s-output=4 NADH, 2 FADH2, 2ATP-2 turns of the cycle per molecule of glucoseFrom the Bridge and Kreb’s cycle combined, one molecule of glucose produces 6NADH, 2 FADH2, and 2ATPOxidative Phosphorylation-takes place in the inner mitochondrial membrane-O₂ required-input= electrons from NADH and FADH2-output= ATP and H₂O-phosphorylation means a phosphate was added to ADP to make ATPUnderstand chemiosmosis and what occurs during this process-coupling an endergonic and exergonic reaction-electrons from NADH and FADH2 are donated to the electron transport chain. The electrons gettransferred to increasingly electronegative molecules. Each transfer releases energy. Energy is used to actively transport protons from the matrix to intermembrane space. This builds a proton gradient. Protons naturally diffuse down the concentration gradient, back into the matrix, activating the enzyme ATP synthase in the process. This allows for ATP to be produced. At the end of the electron transport chain, the electrons are transferred to oxygen, producing water.Chapter 10:Have a general understanding of the goal of photosynthesis and what happens during this process-Redox reaction that requires CO₂ and H₂O and sunlight. Electrons are transferred from a more electronegative molecule(water) to a less electronegative molecule(CO₂). This requires energy which comes from sunlight. This produces sugar(glucose) and oxygen.-the overall chemical change that occurs during photosynthesis is the exact opposite of cellular respiration. When electrons get transferred to less electronegative atoms, it is easier to take away.-occurs in 2 stages: light reaction and calvin cycle; during a light reaction, solar energy is converted to chemical energy. Water is split, providing a source of electrons. Light absorbed by
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