Exam 1 study guide 9.06.2014
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The document provides an outline and study guide for three chapters of a biology exam. Chapter 1 discusses scientific thinking and the scientific method, including making observations, formulating hypotheses, conducting experiments, and drawing conclusions. Chapter 2 examines the basic chemistry of life, such as atoms, elements, bonding, and macromolecules like carbohydrates, lipids, proteins and nucleic acids that are essential to living organisms. Chapter 3 covers cell structure, comparing and contrasting plant and animal cells, and outlining the main cell organelles and their functions. The study guide provides an overview of the key topics and concepts to focus on for the exam.
Exam 1 study guide 9.06.2014
- 1. HollingsworthBiologyExam1StudyGuide 09/06/2014 Chapter 1 Biology Biological Literacy Superstitions Scientific discipline What does empirical mean? Can scientists change their minds? Steps of the scientific method Observations Hypotheses Predictions Theories Laws Placebo Echinacea example Experiment Testable Scientific theory (and how it differs from the common use of the word theory Controlled experiments Double-blind study Treatment group v. Control Group Why do scientists use statistics? Anecdotal evidence What is pseudoscience? Branches of science Systems of nature What cannot be answered using the scientific method? Chapter 2 Element Atom Protons Neutrons Electrons Nucleus How many different elements are found in your body? Atomic number Atomic mass Four most abundant elements in the human body Ion Ionic bond Covalent bond
- 2. HollingsworthBiologyExam1StudyGuide 09/06/2014 Hydrogen bond Molecules Why do certain chemicals have certain tastes? Importance of water Coastal climates v. Inland climates pH Acidity Base/alkalinity Carbohydrates Lipids Proteins Nucleic acids Monosaccharides Insoluble fiber Hydrocarbons Cell membranes DNA sequences DNA – RNA Nucleotides Chapter 3 Plant cell Animal cell Similarities and differences Cell organelles (names and general functions) Cell wall, cell membrane, plasma membrane Prokaryotic Eukaryotic Cell theory Youtube Videos – watch them again! Review your notes. Re-write your notes. Study! Focus! https://www.youtube.com/channel/UCERU5ulJjCLZSwlRPZ7kgYw Here is a general outline of the three chapters in unit one, which will be on the first exam. If you are looking for the concepts, this will help you look! Chapter 1 Scientific Thinking Chapter Outline
- 3. HollingsworthBiologyExam1StudyGuide 09/06/2014 1 Science is a collection of facts and a process for understanding the world. 1.1 What is science? What is biology? TAKE-HOME MESSAGE 1.1: Through its emphasis on objective observation, description, and experimentation,science isapathwaybywhichwe candiscoverandbetterunderstandthe world around us. 1.2 Biological literacy is essential in the modern world. TAKE-HOME MESSAGE 1.2: Biological issues permeate all aspects of our lives. To make wise decisions, it is essential for individuals and societies to attain biological literacy. 1.3 The scientific method is a powerful approach to understanding the world. TAKE-HOME MESSAGE 1.3: There are numerouswaysof gainingan understandingof the world. Because itis empirical,rational,testable,repeatable,andself-correcting,the scientificmethodis a particularly effective approach. 2 A beginner’s guide: what are the steps of the scientific method? 1.4 Thinking like a scientist: how do you use the scientific method? TAKE-HOME MESSAGE1.4: The scientificmethod(observation,hypothesis,prediction,test,and conclusion) isaflexible,adaptable,andefficientpathwaytounderstandingthe world,because it tells us when we must change our beliefs. 1.5 Step 1: Make observations. TAKE-HOME MESSAGE1.5: The scientificmethodbeginsbymakingobservationsaboutthe world, noting apparent patterns or cause-and-effect relationships. 1.6 Step 2: Formulate a hypothesis. TAKE-HOME MESSAGE1.6: A hypothesisisaproposedexplanationforanobservedphenomenon. 1.7 Step 3: Devise a testable prediction. TAKE-HOME MESSAGE 1.7: Fora hypothesistobe useful,itmustgenerateatestable hypothesis. 1.8 Step 4: Conduct a critical experiment.
- 4. HollingsworthBiologyExam1StudyGuide 09/06/2014 TAKE-HOME MESSAGE 1.8: A critical experiment is one that makes it possible to decisively determine whether a particular hypothesis is correct. 1.9 Step 5: Draw conclusions, make revisions. TAKE-HOME MESSAGE1.9: Basedonthe resultsof experimental tests,wecanreviseahypothesis and explainthe observable worldwithincreasingaccuracy.A great strengthof scientificthinking, therefore, is that it helps us understand when we should change our minds. 1.10 When do hypotheses become theories, and what are theories? TAKE-HOME MESSAGE1.10: Scientifictheoriesdonotrepresentspeculationorguessesaboutthe natural world. Rather, they are hypotheses—proposed explanations for natural phenomena— thathave beensostronglyandpersuasivelysupportedbyempirical observationthatthe scientific community views them as very unlikely to be altered by new evidence. 3 Well-designed experiments are essential to testing hypotheses. 1.11 Controllingvariablesmakesexperimentsmore powerful. TAKE-HOME MESSAGE 1.11: To draw clear conclusionsfromexperiments,itisessential tohold constantall those variableswe are notinterestedin.Control andexperimental groupsshould differonlywithrespecttothe treatmentof interest.Differencesinoutcomesbetweenthe groupscan thenbe attributedtothe treatment. 1.12 Repeatableexperimentsincreaseourconfidence. TAKE-HOME MESSAGE 1.12: Experimentsandtheiroutcomesmustbe repeatable fortheir conclusionstobe consideredvalidandwidelyaccepted. 1.13 We’ve gotto watchout for our biases. TAKE-HOME MESSAGE 1.13: Biasescan influence ourbehavior,includingourcollectionand interpretationof data.Withcareful controls,itispossibletominimize suchbiases. 4 The scientific method can help us make wise decisions. 1.14 Visual displays of data can help us understand and explain phenomena. TAKE-HOME MESSAGE 1.14: Visual displaysof data,whichcondense large amounts of information,canaidinthe presentationandexplorationof the data.The effectiveness of suchdisplaysisinfluencedbythe precisionandclarityof the presentation,anditcan be reducedbyambiguity,biases,hiddenassumptions,andotherissuesthatreduce a viewer’s confidence inthe underlyingtruthof the presentedphenomenon.
- 5. HollingsworthBiologyExam1StudyGuide 09/06/2014 1.15 Statistics can help us in making decisions. TAKE-HOME MESSAGE 1.15: Because much variationexistsinthe world,statistics can helpusevaluate whetheranydifferencesbetweenatreatmentgroupanda control group can be attributedtothe treatmentratherthanrandom chance. 1.16 Pseudoscience and misleading anecdotal evidence can obscure the truth. TAKE-HOME MESSAGE 1.16: Pseudoscienceandanecdotal observationsoftenlead people tobelieve thatlinksbetweentwophenomenaexist,wheninfactthere are nosuch links. 1.17 There are limitstowhatscience can do. TAKE-HOME MESSAGE 1.17: Althoughthe scientificmethodmaybe the most effectivepathtowardunderstandingthe observableworld,itcannotgive usinsightsinto the generationof value judgmentsandothertypes of non-quantifiable,subjective information. 5 On the road to biological literacy: what are the major themes in biology? 1.18 A few important themes tie together the diverse topics in biology. TAKE-HOME MESSAGE 1.18: Although the diversityof life on earth is tremendous, the study of life is unified by the themes of hierarchical organization and the power of evolution. Chapter 2 Chemistry Chapter Outline 1 Atoms form molecules through bonding. 2.1 Everything is made of atoms. TAKE-HOME MESSAGE 2.1: Everythingaroundus,livingornot,ismade upof atoms,the smallest unitsintowhichmaterialcanbe dividedwithoutlosingitsessentialproperties.Allatomshavethe same general structure.Theyare made upof protonsandneutronsinthe nucleus,and electrons, which circle far and fast around the nucleus.
- 6. HollingsworthBiologyExam1StudyGuide 09/06/2014 2.2 An atom’s electrons determine how (and whether) the atom will bond with other atoms. TAKE-HOME MESSAGE 2.2: The chemical characteristics of an atom depend on the number of electronsinitsoutermostshell.Atomsare moststable andleastlikelytobondwithotheratoms when their outermost electron shell is filled to capacity. 2.3 Atoms can bond together to form molecules or compounds. TAKE-HOME MESSAGE2.3: Atomscanbe boundtogetherinthreedifferentways.Covalentbonds occur whenatomsshare electrons.Inionicbonds,oneatomtransfersitselectronstoanotherand the two oppositely charged ions are attracted to each other, forming a compound. Hydrogen bonds, which are weaker than covalent and ionic bonds, involve the attraction between a hydrogen atom and a polar molecule. 2 Water has features that enable it to support all life. 2.4 Hydrogen bonds make water cohesive. TAKE-HOME MESSAGE 2.4: Water molecules easily form hydrogen bonds, giving water great cohesiveness. 2.5 Water has unusual properties that make it critical to life. TAKE-HOME MESSAGE 2.5: The hydrogenbondsbetweenwatermoleculesgive waterseveral of its most important characteristics,including cohesiveness,reduced densityas a solid, the ability toresisttemperaturechanges,andbroadeffectivenessasasolventforionicandpolarsubstances. 2.6 Living systems are highly sensitive to acidic and basic conditions. TAKE-HOME MESSAGE 2.6: The pH of a fluid is a measure of how acidic or basic the solution is anddependsonthe concentrationof dissolvedH+ ionspresent.Acids,suchasvinegar,candonate protons to other chemicals; bases, including baking soda, bind with free protons. 3 Carbohydrates are fuel for living machines. 2.7 Carbohydrates include macromolecules that function as fuel. TAKE-HOME MESSAGE 2.7: Carbohydratesare the primaryfuel forrunningall cellularmachinery and also form much of the structure of cells in all life forms. Carbohydrates contain carbon, hydrogen, and oxygen, and generally have the same number of carbon atoms as they do H2O units.The simplestcarbohydrates,includingglucose,are monosaccharidesorsimple sugars.They containfromthree tosix carbonatoms.Asthe chemicalbondsof carbohydratesare brokendown and other more stable bonds are formed, a great deal of energy is released that can be used by organisms. 2.8 Glucose provides energy for the body’s cells.
- 7. HollingsworthBiologyExam1StudyGuide 09/06/2014 TAKE-HOME MESSAGE 2.8: Glucose is the most important carbohydrate to living organisms. Glucose in the bloodstream can be used as an energy source, can be stored as glycogen in the muscles and liver for later use, or can be converted to fat. 2.9 Many complex carbohydrates are time-released packets of energy. TAKE-HOME MESSAGE 2.9: Multiple simple carbohydrates are sometimes linked together into more complex carbohydrates. Types of complex carbohydrates include starch, which is the primaryformof energystorage inplants,and glycogen,whichisaprimaryformof energystorage in animals. 2.10 Not all carbohydrates are digestible. TAKE-HOME MESSAGE 2.10: Some complex carbohydrates,includingchitinandcellulose,cannot be digested by most animals. Such indigestible carbohydrates in the diet, called fiber, aid in digestion and have many health benefits. 4 Lipids store energy for a rainy day. 2.11 Lipids are macromolecules with several functions, including energy storage. TAKE-HOME MESSAGE 2.11: Lipids are insoluble in water and greasy to the touch. They are valuable toorganismsforlong-termenergystorage andinsulation,inmembrane formation,and as hormones. 2.12 Fats are tasty molecules too plentiful in our diets. TAKE-HOME MESSAGE2.12: Fats,includingthe triglyceridescommoninthe foodwe eat,are one type of lipid. Characterized by long hydrocarbon tails, fats effectively store energy in the many carbon-hydrogen and carbon-carbon bonds. Their caloric density is responsible for humans’ preferring fats to other macromolecules in the diet, and is also responsible for their association with obesity and illness in the modern world. 2.13 Cholesterol and phospholipids are used to build sex hormones and membranes. TAKE-HOME MESSAGE 2.13: Cholesterol andphospholipidsare lipidsthatare not fats. Both are important components in cell membranes. Cholesterol also serves as a precursor to steroid hormones, important regulators of growth and development. 5 Proteins are versatile macromolecules that serve as building blocks. 2.14 Proteins are bodybuilding macromolecules.
- 8. HollingsworthBiologyExam1StudyGuide 09/06/2014 TAKE-HOME MESSAGE 2.14: Unique combinations of 20 amino acids give rise to proteins, the chief building blocks of the physical structures that make up all organisms. Proteins perform myriadfunctions,fromassistingchemicalreactionstocausingbloodclottingtobuildingbonesto fighting microorganisms. 2.15 Proteins are an essential dietary component. TAKE-HOME MESSAGE2.15: Twentyaminoacids make up all the proteinsnecessaryforgrowth, repair, and replacement of tissue in living organisms. Of these amino acids, about half are essential forhumans:theycannot be synthesizedbythe body so must be consumedin the diet. Complete proteins contain all essential amino acids, while incomplete proteins do not. 2.16 A protein’s function is influenced by its three-dimensional shape. TAKE-HOME MESSAGE 2.16: The particular aminoacid sequence of a proteindetermineshowit folds into a particular three-dimensional shape. This shape determines many of the protein’s features, such as the moleculesit will interact with. When a protein’s shape is deformed,the protein usually loses its ability to function. 2.17 Enzymes are proteins that initiate and speed up chemical reactions. TAKE-HOME MESSAGE 2.17: Enzymes are proteins that help initiate and speed up chemical reactions.Theyaren’tpermanentlyalteredinthe process,butrathercanbe usedagainandagain. 2.18 Enzymes regulate reactions in several ways (but malformed enzymes can cause problems). TAKE-HOME MESSAGE2.18: Enzyme activityisinfluencedbyphysical factorssuchastemperature and pH, as well as chemical factors, including enzyme and substrate concentrations. Inhibitors and activators are chemicalsthatbind to enzymesandby blockingthe active site or alteringthe shape or structure of the enzyme canchange the rate at which the enzyme catalyzes reactions. 6 Nucleic acids store the information on how to build and run a body. 2.19 Nucleic acids are macromolecules that store information. TAKE-HOME MESSAGE 2.19: The nucleic acids DNA and RNA are macromolecules that store information in their unique sequences of bases contained in nucleotides, their building-block molecules. Both nucleic acids play central roles in directing protein production in organisms. 2.20 DNA holds the genetic information to build an organism. TAKE-HOME MESSAGE 2.20: DNA islike a ladderinwhichthe longvertical sidesof the ladderare made froma sequence of sugar-phosphate-sugar-phosphatemoleculesandthe rungsare pairsof
- 9. HollingsworthBiologyExam1StudyGuide 09/06/2014 nucleotide bases. The sequence of nucleotide bases contains the information about how to produce a particular protein. 2.21 RNA is a universal translator, reading DNA and directing protein production. TAKE-HOME MESSAGE 2.21: RNA acts as a middleman molecule—taking the instructions for protein production from DNA to another part of the cell where, in accordance with the RNA instructions, amino acids are pieced together into proteins. Chapter 3 Cells Chapter Outline 1 What is a cell? 3.1 All organismsare made of cells. TAKE-HOME MESSAGE 3.1: The mostbasicunitof any organismisthe cell,the smallestunitof life thatcan functionindependentlyandperformall of the necessaryfunctionsof life,including reproducingitself.All livingorganismsare made upof one or more cells,andall cellsarise from other,pre-existingcells. 3.2 Prokaryoticcellsare structurallysimple,butthere are manytypesof them. TAKE-HOME MESSAGE 3.2: Everycell on earthiseithera eukaryoticora prokaryoticcell. Prokaryotes,whichhave nonucleus,werethe firstcellsonearth.Theyare all single-celled organisms.Prokaryotesinclude the bacteriaandarchaeaand,as a group,are characterizedby tremendousmetabolicdiversity. 3.3 Eukaryoticcellshave compartmentswithspecializedfunctions. TAKE-HOME MESSAGE 3.3: Eukaryotesare single-celledormulticellularorganismsconsistingof cellswithanucleusthatcontainslinearstrandsof geneticmaterial.The cellsalsocommonly have organellesthroughouttheircytoplasm;these organellesmayhave originated evolutionarilythroughendosymbiosisorinvagination,orboth. 2 Cell membranes are gatekeepers.
- 10. HollingsworthBiologyExam1StudyGuide 09/06/2014 3.4 Everycell isborderedbya plasmamembrane. TAKE-HOME MESSAGE 3.4: Everycell of everylivingorganismisenclosedbyaplasma membrane,atwo-layeredmembranethatholdsthe contentsof acell inplace and regulates whatentersand leavesthe cell. 3.5 Moleculesembeddedinthe plasmamembrane helpitperformitsfunctions. TAKE-HOME MESSAGE 3.5: The plasmamembrane isafluidmosaicof proteins,lipids,and carbohydrates.Proteinsfoundinthe plasmamembrane enable ittocarry outmost of its gatekeepingfunctions.The proteinsactas receptors,helpmoleculesgainentryintoandexit fromthe cell,andcatalyze reactionsonthe innerandoutercell surfaces.Inconjunctionwith carbohydrates,some plasmamembrane proteinsidentifythe cell toothercells.And,inaddition to the phospholipidsthatmake upmostof the plasmamembrane,cholesterol isanimportant lipidinsome membranes,influencing fluidity. 3.6 Faultymembranescancause disease. TAKE-HOME MESSAGE 3.6: Normal cell functioningcanbe disruptedwhencell membranes— particularlythe proteinsembeddedinthem—donotfunctionproperly.Suchmalfunctionscan cause healthproblems,such ascysticfibrosis.Butdisruptionof normal cell membrane function can alsohave beneficial,therapeuticeffects,suchasinthe treatmentof highbloodpressure and anxiety. 3.7 Membrane surfaceshave a “fingerprint”thatidentifiesthe cell. TAKE-HOME MESSAGE 3.7: Everycell inyour bodyhas a “fingerprint”made fromavarietyof moleculesonthe outside-facingsurface of the cell membrane.Thismolecularfingerprintiskey to the functionof yourimmune system. 3 Molecules move across membranes in several ways. 3.8 Passive transportisthe spontaneousdiffusionof moleculesacrossamembrane. TAKE-HOME MESSAGE 3.8: For properfunctioning,cellsmustacquire foodmoleculesand/or othernecessarymaterialsfromoutsidethe cell.Similarly,metabolicwaste moleculesand moleculesproducedforuse elsewhere inthe bodymustmove outof the cell.Inpassive transport—whichincludessimple andfacilitateddiffusionandosmosis—themolecular movementoccursspontaneously,withoutthe inputof energy.Thisgenerallyoccursas moleculesmovedowntheirconcentrationgradient. 3.9 Osmosisisthe passive diffusionof wateracrossa membrane. TAKE-HOME MESSAGE 3.9: The diffusionof wateracrossa membrane isa special type of passive transportcalledosmosis.Watermoleculesmoveacrossthe membrane until the concentrationof waterinside andoutside the cell isequalized.
- 11. HollingsworthBiologyExam1StudyGuide 09/06/2014 3.10 Inactive transport,cellsuse energytomove small moleculesintoandoutof the cell. TAKE-HOME MESSAGE 3.10: In active transport,movingmoleculesacrossamembrane requires energy.Active transportisnecessaryif the moleculestobe movedare verylarge or if theyare beingmovedagainsttheirconcentrationgradient.Proteinsembeddedinthe plasmamembrane act like motorizedrevolvingdoorstoactivelytransport(pump) the molecules. 3.11 Endocytosisandexocytosisare usedforbulktransportof particles. TAKE-HOME MESSAGE 3.11: When materialscannotgetintoa cell viadiffusionora pump(e.g., whenthe moleculesare toobig),cellscanengulf the moleculesorparticleswiththeirplasma membrane ina processcalledendocytosis.Similarly,moleculescanbe movedoutof a cell via exocytosis.Inbothprocesses,the plasmamembrane movestosurroundthe moleculesor particlesandformsa little vesicle thatispinchedoff inside the cell (endocytosis) orfuseswith the plasmamembrane anddumpsitscontentsoutside the cell (exocytosis). 4 Cells are connected and communicate with each other. 3.12 Connectionsbetweencellsholdtheminplace andenable themtocommunicate witheach other. TAKE-HOME MESSAGE 3.12: In multicellularorganisms,mostcellsare connectedtoothercells. The connectionscanform a water-tightseal betweenthe cells(tight junctions),canholdsheets of cellstogetherwhile allowingfluidtopassbetweenthe cell (desmosomes),orcanfunctionlike secretpassageways,allowingthe movementof cytoplasm, molecules,andothersignals betweencells(gapjunctions). 5 Nine important landmarks distinguish eukaryotic cells. 3.13 The nucleusisthe cell’sgeneticcontrol center. TAKE-HOME MESSAGE 3.13: The nucleusisusuallythe largestandmostprominentorganellein the eukaryoticcell.Itdirectsmostcellularactivitiesbycontrollingwhichmoleculesare produced and inwhat quantity.The nucleusisalsothe storehouseforall hereditaryinformation. 3.14 Cytoplasmandthe cytoskeletonformthe cell’sinternal environment,provide its physical support,andcan generate movement. TAKE-HOME MESSAGE 3.14: The innerscaffoldingof the cell,whichismade fromproteins,is the cytoskeleton.Consistingof three typesof proteinfibers—microtubules,intermediate filaments,andmicrofilaments—the cytoskeletongivesanimal cellstheirshape andsupport, givescellssome abilitytocontrol theirmovement,andservesasaseriesof tracks onwhich organellesandmoleculesare guidedacrossandaroundthe inside of the cell. 3.15 Mitochondriaare the cell’senergyconverters.
- 12. HollingsworthBiologyExam1StudyGuide 09/06/2014 TAKE-HOME MESSAGE 3.15: In mitochondria,whichare foundinnearlyall eukaryoticcells,the energycontainedinthe chemical bondsof carbohydrate,fat,andproteinmoleculesis convertedintocarbondioxide,water,andATP,the energysource forall cellularfunctionsand activities.Mitochondriamayhave theirevolutionaryoriginsassymbioticbacterialivinginside othercells. 3.16 Lysosomesare the cell’sgarbage disposals. TAKE-HOME MESSAGE 3.16: Lysosomesare round,membrane-enclosed,acid-filledorganelles that functionas a cell’sgarbage disposals.Theyare filledwithabout50 differentdigestive enzymesandenable acell todismantle macromolecules,includingdisease-causingbacteria. 3.17 The endoplasmicreticulumisthe site where cellsbuildproteinsanddisarmtoxins. TAKE-HOME MESSAGE 3.17: The productionandmodificationof biological moleculesin eukaryoticcellsoccursina systemof organellescalledthe endomembrane system, which includes,amongotherorganelles,the roughandsmoothendoplasmicreticulum.InroughER, proteinsthatwill be shippedelsewhere inthe bodyare foldedandpackaged.Inthe smoothER, lipidsare synthesizedandalcohol,antibiotics,andotherdrugsare detoxified. 3.18 The Golgi apparatus isthe site where the cell processesproductsfordelivery throughoutthe body. TAKE-HOME MESSAGE 3.18: The Golgi apparatus—anotherorganellewithinthe endomembranesystem—processesmoleculessynthesizedinacell andpackagesthose thatare destinedforuse elsewhere inthe body. 3.19 The cell wall providesadditionalprotectionandsupportforthe plantcells. TAKE-HOME MESSAGE 3.19: The cell wall isan organelle foundinplants(andinsome other non-animal organisms).Itismade primarilyfromthe carbohydrate celluloseanditsurrounds the plasmamembrane of the cell.The cell wall conferstremendousstructural strengthonplant cells,givesplantsincreasedresistance towaterloss,andprovidessomeprotectionfrominsects and otheranimalsthatmighteat them.Inplants,plasmodesmata connectcellsand enable communicationandtransportbetweenthem. 3.20 Vacuolesare multipurpose storage sacsforcells. TAKE-HOME MESSAGE 3.20: In plants,vacuolescanoccupymost of the interiorspace of the cell.Vacuolesare alsopresentinsome othereukaryoticspecies.Theyfunctionasstorage spaces and playa role innutrition,waste management,predatordeterrence,reproduction,and physical support. 3.21 Chloroplastsare the plantcell’spowerplant. TAKE-HOME MESSAGE 3.21: The chloroplastisthe organelle inplantsandalgae thatisthe site of photosynthesis—the conversionof lightenergyintochemical energy,withoxygenasaby- product.Chloroplastsmayhave originallybeenbacteriathatwere engulfedbyapredatorycell by endosymbiosis.