Exam 2 Study guide
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This 16 page Bundle was uploaded by Jon Connor Davis on Thursday October 6, 2016. The Bundle belongs to 1000 at Auburn University taught by Professor Mays in Fall 2016. Since its upload, it has received 180 views. For similar materials see Introduction to Biology in Biology at Auburn University.
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Date Created: 10/06/16
Scanned by CamScanner Scanned by CamScanner Scanned by CamScanner Scanned by CamScanner Scanned by CamScanner Intro to Biology Exam 2 Study Guide Chapter 6: Energy, Enzymes, and Metabolism: Metabolism: the sum of all chemical reactions that an organismcarries out Energy- abilityto do work Potential energy: stored energy Chemical Energy: energy contained inthe chemical bonds ofmolecules Kinetic energy: energy of motion Mechanical Energy: conversion of chemical energy to kinetic energy st Lawof Conservation of Energy (1 lawof Thermodynamics): Energy cannot be created, or destroyed, but canchange forms Second Lawof Thermodynamics: Energy cannot change forms without a loss of usable energy. Lawof entropy: (the relative amount of disorder in a system) o Example of Entropy: o C H6 12 C6 +H O :2luc2seis moreorganized and less stable,whileits products are more stable,but less organized Anabolism: building up of molecules Catabolism:breaking down of molecules Reactant: substances that participate ina reaction. Products: substances that form due to a reaction Exergonic reactions: energy is released;products have less energythan reactants; spontaneous. Endergonic reactions: energy is required; products have more energy than reactants; spontaneous. ATP: the “currency” of the cell. o Usein chemical work: energy to synthesizeMacromolecules o Transport Work: energy to pump things across membranes o Mechanical work: energy used to make muscles contract, cilia,flagella,etc. Adenine: baseof DNA and RNA Ribose:Pentose sugarfound in RNA Coupled Reactions: Theenergy releasedby an exergonic reaction is usedto drive an endergonic reaction Enzymes: typicallyproteins that function as catalysts tospeed a chemical reaction. (lower the energy needed for a reaction.) Substrate: reactants in anenzymatic reaction Energy of Activation: energy that must be added for molecules to react with one another Active site:location on the enzyme that complexes with the substrate Factors affecting Enzymatic speed: o Substrate concentration: enzyme activity increases as substrateincreases.(There is a maximum rate of enzyme activity however). o Temperature and Ph: Rateof reactions goes up as Temp goes up (Unless too hot, canbecome denatured). Every enzyme has a preferred Ph. o Enzyme Activation: Not all enzymes are needed by the cell all the time. A cell can regulate which ones are active.Enzymes can be modified by adding or removing phosphates, this changes the shape. o Enzyme Inhibition: Competitive and non-competitive inhibitors keep the enzyme from working. Ex: cyanide and penicillin. o Enzyme Cofactors: bind to an enzyme to aid ina reaction. Inorganic ions are cofactors: zinc, iron, copper. Organic non-protein cofactors are calledcoenzymes Reduction: gainof electrons OIL RIG Oxidation: Loss ofElectrons Oxidation Is Lost Reduction Is Gain Know the formulas for Photosynthesis and CellularRespiration To know whether a molecule is oxidized or reduced, follow the reactants,and seeifH is added or lost Ex: CO2 C H6 12 6 :Hydrogen was added, soCO was2reduced. Anything ending in ASE is anenzyme Chapter 7: CellularRespiration: CellularRespiration: alsoknown as Aerobic Respiration, Requires O ,releases CO ,itis 2 2 an aerobic process.Usuallyinvolves the complete breakdown of glucose: o C H O +6O 6CO +6H O 6 12 6 2 2 2 o ADP+P 36-38 ATP Coenzymes: help an enzyme do its job and may even participate in the reaction o NAD : used as anelectron carrier, becomes NADH o FAD: alsoused as anelectron carrier, becomes FADH 2 3 Phases ofCellularRespiration: o Glycolysis o Citric Acid Cycle/Prep reaction o Electron Transport Chain Glycolysis:the breakdown of glucoseto 2 molecules of pyruvate o Takes placeinthe cytoplasm o Does not require oxygen o Transforms one 6-carbon molecule, into two 3-carbon molecules Input Output 6C glucose 2 (3C)pyruvate 2 NAD + 2 NADH *Net gainof 2 ATP 2 ATP 2 ADP 4 ADP +P 4 ATP Total o 2 steps: Energy Investment: 2 molecules of ATP activateglucose Energy Harvesting: Oxidation ofG3P results inNADH synthesis,and formation of 4 ATP Startwith 6-carbon glucose 2 ATP are addedto form ADPand attach two phosphatesto theglucose G3P givesup twoelectronsto convertNAD to NADH and onePis added and thepyruvatesnowhave two phosphorousattached One Phosphorousisgivenup to convertADPto ATP Waterisremoved SubstratelevelATPSynthesis occurs,givingupthefinalPhosphorous to give us ourpyruvates,now readyfor the Prep reaction. Net Gain of 2ATP!!! Prep Reaction: o Pyruvate is converted to an acetyl group, attached to coenzyme A (CoA), 2nd CO is givenoff. o Hydrogen atoms are removed from pyruvate by NAD to form NADH + H + o This all happens TWICEPER GLUCOSEMOLECULE!!! o 2 pyruvate + 2CoA 2 acetyl CoA +2 CO (N2D + NADH+H ) + Citric Acid Cycle o Occurs in the matrix of the mitochondria o Each2 Carbon Acetyl group is oxidized to two CO mo2ecules o 3 NADH+ H & 1FADH 2 o 1 ATP by substrate level synthesis o cycleturns twice per glucose Inputs Outputs 2 Acetyl groups 4 CO2 + + 6 NAD 6 NADH+H 2 FAD 2 FADH 2 2 ADP+P 2 ATP *Figure 7.6 in the book Mitochondria: “powerhouse” siteof cellularrespiration Matrix: inner fluid-filledspaceof the Mitochondria Electron Transport Chain: o In the cristaeof the Mitochondria o Electrons are passedbetween electron carriers o Highenergy electrons enter, low energy electrons leave o Eachcarrier is reduced, then oxidized o Energy is needed to create a hydrogen ion gradient o https://youtu.be/xbJ0nbzt5Kw This is a linkto the video we watched in class, you don’t need to know all the littlenames, justget a visual on how the hydrogen ion gradient is formed, and how the ATP synthasecomplex is powered. ATP Synthesis: + o Usegradient of H ions o Energy is captured to form ADP +P o Process is calledchemiosmosis (FIGURE 7.9FOR VISUAL) In Sum: o We are breaking bonds in glucose,creating bonds elsewhere to transfer potential energy to chemical energy o Energy is transferred to bonds in ATP molecules which areused all over the cell. Fermentation: o Lactic Acid(Animals)and Alcohol (Plants)Fermentation occur when oxygen is limited. o This is calledanaerobic respiration becauseno oxygen is present inthe reaction. Inputs Outputs Glucose 2 lactateor 2 alcohol/ CO2 2 ATP 2 ADP * Net Gainof 2 ATP 4 ADP +2P 4 ATP Chapter 8: Photosynthesis: Photosynthesis: conversion of solar energy to chemical energy Autotroph: anorganism that cando photosynthesis Heterotroph: cannot produce their own chemical energy through photosynthesis Chlorophyll: a pigment, (The most important, reflects green light) Carotenoid: important insome organisms atsome times, such as inthe fall when leaves begin to changecolors. Stomata: small openings in leaves where CO e2ters the plant Visiblelight:Lightthat canbe seenwith the human eye,contains different wavelengths of light Photosynthesis has to sets ofreactions: o Lightreactions: occur in the thylakoid o CalvinCycle/Dark reactions: occur in the stroma of the chloroplast o NADP+ is a cofactor needed for Photosynthesis 6CO 2 6H O 2/solar energy in pigments C H O 6 12 6 + 6O 2 The LightReactions o Energy is absorbed by chlorophyll o Happens inthe thylakoid o Lightenergy is converted to high energy molecules (ATP and NADPH) o Water is split(Oxygenis released) o Fill in all the boxes and circles! Non- cyclic lightreactions: 2photosystems o Water can be traced to a molecule of NADPH Cyclic Lightreactions: 1Photosystem o ATP is all that is formed, and electrons are recycled back to Photosystem I. o Energized electrons leavephotosystem I and return by an electron transport chain. o ATP from cyclic electron transport used in Calvincycleto make carbohydrates Thylakoid Membrane Organization: o Photosystem II: Pigment complex and electron acceptors Water is splitto replace energized electrons 0xygen is released o Electron Transport Chain Carries electrons from PS II to PS I Uses energy to pump H ions from the stroma into the thylakoid space o Photosystem I: Pigment complex and electron acceptors Adjacent to enzymes that reduce NADP+ to NADPH o ATP Synthase Complex Has a channel for H flow Flow drives ATP synthaseto join ADP +P Figure 8.8 in book CalvinCycle/Dark Reactions CO 2ixation o Step 1: CO is attachedto RuBP 2 o We have a 6 carbon molecule, which divides into two 3 carbon molecules (3PG) CO 2eduction o 3PG is reduced to G3P o Energy and electrons from the lightreactions RuBP regeneration o After 3turns, One G3P (carbohydrate) canleavethe cycle o After 3turns, 5 G3P rearrange to 3 RuBP(5 Carbon molecule) Reduction of Carbon Dioxide: ATP ADP+P 3PG BPG G3P NADPH NADP+ Both plants and animals do cellularrespiration Plant cells photosynthesize, animals do not. Chapter 5: Mitosis and Meiosis: Mitosis:occurs after interphase, is thedivision of the nucleus Meiosis:cell divisionfor sexual reproduction. 1 diploid parent cell becomes 4 haploid cells.Divisionhappens twice Chromatin: DNA +Proteins Somatic Cells:Bodycells Daughter cells:divided somatic cells thatcome from their parent Chromatids: one molecule of DNA Chromosomes: formed when chromatin coil up when the cell is preparing to divide Centromere: region that holds together the two sisterchromatids Apoptosis: programmed cell death, important part of cell development Ploidy: n, humans are 2n (ploidy is thenumber of copies of a chromosome Interphase: o G :1rowth (There is a checkpoint after this stage) o S: growth and DNA replication o G :2rowth and final preparations for division (Final checkpoint before mitosis) Mitosis o Early Prophase: Chromosomes begin to condense, nuclear envelope breaks down o Prophase: Chromosomes condense Spindle is formed Nuclear envelope is gone Centrosomes beginto separate o Prometaphase Chromosomes move Polar spindle fibers stretch from eachpole and overlap o Metaphase: chromosomes lineup atthe center o Anaphase: sisterchromatids pull apart and become daughter chromosomes, eachpole receives anidentical set o Telophase:Cytokinesis begins,nuclear envelope and nucleoli reappear, chromosomes decondense Cytokinesis: o Divisionof the cytoplasm o Usuallyresults in identical daughter cells (fewexceptions) o Happens differently for plants and animals In plants: A cell plateis formed In Animals: a cleavagefurrow is formed Needs ofCell division: o Anchorage Dependence: most cells divideonly when attached to a surface o Densitydependence inhibition: cells divideuntil they touch each other and then stop. 2 types of genes control the cell cycleinCANCER: o Proto-oncogenes: encode proteins that promote the cell cycleand prevent apoptosis. Canbecome ONCOGENES(Cancercausing)ifmutated o Tumor Suppressor Genes: Encode proteins that stop cell cycleand promote apoptosis Benigntumors: non-cancerous Malignant tumors: cancerous Metastasis:spreadof cancer cells Carcinomas: cancers that start in lining,external or internal Sarcomas: cancer in bone or muscle Leukemias and Lymphomas: cancer in blood producing tissue Treatments: Chemotherapy and Radiation Meiosis I: homologous chromosome pairs separate Meiosis II: sisterchromatids separate Stages of Meiosis I: o Prophase I: Homologous chromosomes pair during synapsis DNA replication Variations via crossing over o Metaphase I: Homologous chromosome pairs alignatthe metaphase plate Independent assortment o Anaphase I: Homologues separate likein Mitosis o TelophaseI: Daughter cells formas inMitosis o Interkinesis: stagebetween Meiosis I and II.At this point: CHROMOSOMES STILL CONSIST OFTWO CHROMATIDS. Meiosis IIresults in 4 haploid daughter cells,primed for sexual reproduction. Egg and Sperm cells:1N Body cells:2N Fertilized egg:2N I hope this study guide is helpful!!! Besure to read the chapters ifyou haven’t. If you have any questions, email me at email@example.com
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