Exam 3 Study Guide Chapter 8 Understand the difference between anabolic and catabolic pathways Catabolic pathways involve the breaking down of large molecules releases energy Anabolic pathways involve building requires energy sometimes called biosynthetic pathways Understand the first 2 laws of thermodynamics and how they relate to energy exchange First Law of Thermodynamics energy can be transferred and transformed but it cannot be destroyed principle of conservation of energy Second Law of Thermodynamics any time energy is transformed some of it is lost as heat Know the Free Energy equation and be able to calculate G G G final products G starting reactants G change in free energy H enthalapy total energy T temperature S change in entropy T S energy not available to do work G H T S G 0 chemical equilibrium and no work can be done energy was released during the reaction energy was required for the reaction Know the characteristics of endergonic and exergonic reactions Endergonic require the input of energy and have a positive G number they are energetically uphill non spontaneous reaction products have more free energy than reactants Exergonic release energy when they occur and have a negative G products have less free energy than the reactants spontaneous reaction energetically downhill Understand how ATP hydrolysis provides energy for endergonic reactions Extremely exergonic reaction it releases 7 3 kCal Mol this energy must go somewhere so it is used to power an endergonic reaction ATP H O ADP P P inorganic phosphate Understand how enzymes catalyze chemical reactions Enzymes catalyze reactions by lowering activation energy This does not affect the free energy of the reactants or the products Understand the different types of enzyme inhibitors and how they work Competitive Inhibitors compete with the substrate and actually bind to the active site of an enzyme reducing enzymatic activity also called mimics Allosteric 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 cell Chapter 9 Understand what happens during redox reactions Redox 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 agents Oxidizing agent receives an electron and allows another atom to be reduced Reducing agent donates an electron and allows another atom to be oxidized Oxidation is a reaction with oxygen Understand what happens during fermentation and why our cells perform this reaction The 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 requirements Glycolysis 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 s Bridge Reaction happens in the mitochondrial matrix O required from here on out links glycolysis to Kreb s cycle input 2 pyruvates output 2 acetyl CoA s 2 NADH Kreb s Cycle O required input 2 acetyl CoA s output 4 NADH 2 FADH2 2ATP 2 turns of the cycle per molecule of glucose From the Bridge and Kreb s cycle combined one molecule of glucose produces 6NADH 2 FADH2 and 2ATP Oxidative Phosphorylation takes place in the inner mitochondrial membrane O required input electrons from NADH and FADH2 output ATP and H O phosphorylation means a phosphate was added to ADP to make ATP Understand 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 get transferred 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 CO and H O and sunlight Electrons are transferred from a more electronegative molecule water to a less electronegative molecule CO 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 the chlorophyll drives a transfer of electrons to an acceptor called NADP Understand what happens during the Light dependent reaction including each
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