Topic: The Topic: The Science of Science of

Life/ChemistryLife/Chemistry

Characteristics of Living Characteristics of Living OrganismsOrganisms

• OrganizationOrganization• CellsCells• Response to stimuliResponse to stimuli• HomeostasisHomeostasis• MetabolismMetabolism• Growth and developmentGrowth and development• ReproductionReproduction• Evolution—not a charac but importantEvolution—not a charac but important

Unity in the Diversity of LifeUnity in the Diversity of Life

• Three Domains of LifeThree Domains of Life° BacteriaBacteria

° ArchaeaArchaea

° Eukarya (contains nuclei)Eukarya (contains nuclei)

–The six The six kingdomskingdoms include include Archaea, Bacteria, Protista, Archaea, Bacteria, Protista, Fungi, Plantae, and Animalia.Fungi, Plantae, and Animalia.

Unity in the Diversity of LifeUnity in the Diversity of Life

Scientific MethodScientific Method• Not rigid, order/details may varyNot rigid, order/details may vary• 2 types of data:2 types of data:

–Quantitative = use #’sQuantitative = use #’s

–Qualitative = use Qualitative = use descriptive descriptive wordswords

Scientific MethodScientific Method•Collecting observations

•Asking questions

•Forming hypotheses and making predictions

•Confirming predictions (with experiments when needed)

•Drawing conclusions

Controlled ExperimentControlled Experiment• Compares an experimental group Compares an experimental group

and a control group and only has and a control group and only has one variableone variable – keeps all other – keeps all other factors the same factors the same

• Control GroupControl Group - used for - used for comparison (unchanged), part of comparison (unchanged), part of controlled exp.controlled exp.

Scientific MethodScientific Method–theorytheory is a set of related hypotheses is a set of related hypotheses

confirmed to be true many times, confirmed to be true many times, and it can explain a great amount of and it can explain a great amount of data.data.

Scientific MethodScientific Method• Publishing a PaperPublishing a Paper

–Scientists submit research papers to Scientists submit research papers to scientific journals for publication.scientific journals for publication.

–In In peer reviewpeer review, the editors of a , the editors of a journal will send submitted papers journal will send submitted papers out to experts in the field who out to experts in the field who anonymously read and critique the anonymously read and critique the paper.paper.

–Primary sourcePrimary source

Scientific MethodScientific Method• ModelsModels

– Explanation supported by dataExplanation supported by data

– May be visual, verbal, mathematicalMay be visual, verbal, mathematical

• GraphingGraphing– Good visual organizationGood visual organization

– Must contain a Descriptive Title, label Must contain a Descriptive Title, label both axes and include unitsboth axes and include units

° Dependent variable goes up Y axisDependent variable goes up Y axis

MicroscopyMicroscopy• Magnification: apparent sizeMagnification: apparent size• Resolution: clarity of detailsResolution: clarity of details• Power of Magnification:Power of Magnification:

–Ocular (eyepiece) X Objective = Ocular (eyepiece) X Objective = total mag.total mag.

–Actual size =Actual size =

mag. size /magnificationmag. size /magnification

MicroscopyMicroscopy

Light Light MicroscopeMicroscope• Limited Limited

magnificationmagnification

Transmission Electron Transmission Electron Microscope (T.E.M.)Microscope (T.E.M.)

• Aims a beam of electrons instead Aims a beam of electrons instead of light waves of light waves THROUGHTHROUGH a specimen a specimen

• 200,000200,000 times better times better than the eye than the eye

• Looks at Looks at internalinternal structure structure• No living specimensNo living specimens

Scanning Electron Microscope Scanning Electron Microscope (S.E.M.)(S.E.M.)

• Bounces electrons Bounces electrons off specimen's off specimen's surfacesurface

• No living No living specimensspecimens

• Look at Look at surfacesurface of of structurestructure

Building Blocks of Matter = Building Blocks of Matter = CH 2CH 2

• MatterMatter is anything that is anything that occupies space and has occupies space and has mass.mass.

• MassMass is the quantity of is the quantity of matter an object hasmatter an object has

Atomic StructureAtomic Structure• NucleusNucleus = protons = protons (+) and neutrons (0)(+) and neutrons (0)• Electrons (-)Electrons (-) = in = in

clouds around the clouds around the nucleus, at varying nucleus, at varying energy levelsenergy levels

maximum

The The typetype of atom is of atom is determined by the determined by the number of number of protonsprotons in its nucleus.in its nucleus.

• Atomic NumberAtomic Number = # = # protons and # protons and # electronselectrons

• CHONP = 90% of all CHONP = 90% of all living things living things

Atomic ElementsAtomic Elements

• ElementsElements:: substances made of only substances made of only one type of atomone type of atom

– Coal, diamond, goldCoal, diamond, gold• MoleculesMolecules:: two or more atoms bonded two or more atoms bonded

together together

– Oxygen gas, OOxygen gas, O22, and water, , and water, HH22OO

Atoms Combine to Form:Atoms Combine to Form:

OCO

• CompoundsCompounds:: two or more two or more differentdifferent atoms bonded together atoms bonded together

of different elementsof different elements

• NaCl (salt)NaCl (salt)

• HH22SO4 (sulfuric acid)SO4 (sulfuric acid)

Atoms Combine to Form:Atoms Combine to Form:

Ionic BondingIonic Bonding• Within a moleculeWithin a molecule: : Weaker BondWeaker Bond• Results from a Results from a transfertransfer of electrons from of electrons from

one atom to another one atom to another

– ionsions: charged atoms: charged atoms

Covalent BondingCovalent Bonding• Within a moleculeWithin a molecule: : STRONG BONDSTRONG BOND• Results from a Results from a sharingsharing of electrons of electrons

between atomsbetween atoms

Carbon Atom—Can bond with 4 other elements

Hydrogen BondingHydrogen Bonding• Between molecules:Between molecules:• Results from attraction between N,O Results from attraction between N,O

and H in and H in differentdifferent molecules molecules

–Weakest single bondWeakest single bond: strong when all : strong when all summed summed togethertogether

Polar Covalent BondPolar Covalent BondSTRONGEST BONDSTRONGEST BOND• Unequal sharing of electrons between Unequal sharing of electrons between

atoms results in positive and negative atoms results in positive and negative “poles”“poles”

• overall net charge = 0overall net charge = 0• Found in Found in WATER WATER

Chemical Reactions-CH 2Chemical Reactions-CH 2• ReactantsReactants go into equation and go into equation and

productsproducts come out come out

• ReactantsReactants ----> Products----> Products

6CO2 +12H2O+Sun ----> C6H1206 + 6H2O + 6O2

• Most reactions are Most reactions are reversiblereversible• Reversible reactions will approach Reversible reactions will approach

dynamic equilibriumdynamic equilibrium

ReactionsReactions

Reactions Absorb or Reactions Absorb or Release EnergyRelease Energy

Reduction-Oxidation Reduction-Oxidation ReactionsReactions

• Energy is often transferred through Energy is often transferred through electronselectrons = redox reaction…happen at = redox reaction…happen at the same timethe same time

• OxidationOxidation = LOSS of an electron = LOSS of an electron (becomes a + ion like Na(becomes a + ion like Na++))

• ReductionReduction = GAIN of an electron = GAIN of an electron (becomes a negative ion like Cl(becomes a negative ion like Cl--))

• Unique properties good for living Unique properties good for living things:things:

–AdhesionAdhesion and and CohesionCohesion allow it to allow it to travel up a plant, creating:travel up a plant, creating:

°Capillary ActionCapillary Action–cohesion = water + watercohesion = water + water

–adhesion = water + non wateradhesion = water + non water

Properties of WaterProperties of Water

Ionization of WaterIonization of Water• In water, O can pull an H off In water, O can pull an H off

another water moleculeanother water molecule• Results in OH- (Results in OH- (hydroxide ionhydroxide ion) and ) and

a H+ (a H+ (hydrogen ionhydrogen ion))• H+ immediately reacts with another H+ immediately reacts with another

water to form Hwater to form H33O+ (O+ (hydronium ionhydronium ion))

• If # of OH- = # of HIf # of OH- = # of H33O+ (H+) solution O+ (H+) solution

is neutral (pH 7)is neutral (pH 7)

AcidsAcids & & BasesBases• AcidsAcids = solution with more = solution with more HH33O+O+ (H+) than OH- (H+) than OH-

–sour & corrosivesour & corrosive–acidicacidic

• BasesBases = solution with more OH- than = solution with more OH- than HH33O+O+ –bitter & slipperybitter & slippery–Basic or alkalineBasic or alkaline

pH ScalepH Scale• Compares relative concentration of Compares relative concentration of

hydronium (hydronium (HH33O+ ) O+ ) to hydroxide ions (to hydroxide ions (OHOH__))

• Ranges 0 to 14Ranges 0 to 14• Ends of scale = strong, middle is weakEnds of scale = strong, middle is weak• Log scale = each number difference is factor Log scale = each number difference is factor

of 10 (ex. 4 has 10X more of 10 (ex. 4 has 10X more HH33O+ than 5 and O+ than 5 and

100X more H100X more H33O+ than 6)O+ than 6)

Measuring AcidityMeasuring Acidity

BuffersBuffers• Help hold pH constantHelp hold pH constant• Most enzymes can only function in Most enzymes can only function in

a narrow pH rangea narrow pH range

ATPATP• Adenosine triphosphateAdenosine triphosphate

– Composed of adenine, ribose, and Composed of adenine, ribose, and three phosphate groupsthree phosphate groups

– Cell's chief energy source.Cell's chief energy source.

The ATP ADP CycleThe ATP ADP Cycle• Energy input links phosphate to ADP to produce ATPEnergy input links phosphate to ADP to produce ATP

• ADPADP + + PP + + energyenergy ---> ---> ATPATP

(sunlight,(sunlight,chemical energy)chemical energy)

• ATPATP ++ catalyst catalyst ---> ---> ADPADP ++ PP ++ energyenergy

Organic Compounds = CH 3Organic Compounds = CH 3• Compounds that have:Compounds that have:

– Carbon atomsCarbon atoms covalently bonded covalently bonded to each to each other and to H, O, N, other and to H, O, N, P, SP, S

(CHNOPS)(CHNOPS)

Carbon BondsCarbon Bonds

Functional GroupsFunctional Groups

P

Hydroxyl (COH)Hydroxyl (COH)slightly hydrophillic

Ketone (CO)Ketone (CO)slightly hydrophillic

Aldehyde (COH)Aldehyde (COH)slightly hydrophillic

Carboxyl (COOH)Carboxyl (COOH)Moderately hydrophillic

Phosphate (POPhosphate (PO44))slightly hydrophillic

•Usually found at end of carbon chains or regularly interspersed, influence the properties of the molecules they compose

Monomers to Monomers to PolymersPolymers

• Condensation (aka Condensation (aka dehydration dehydration synthesis) synthesis) links links monomers, monomers, produces waterproduces water

• HydrolysisHydrolysis breaks breaks polymers apart – polymers apart – uses wateruses water

Carbohydrates =#1Carbohydrates =#1• Are sugarsAre sugars• Made of C, H, OMade of C, H, O• Can be mono, di, or polysaccharideCan be mono, di, or polysaccharide

Carbohydrates Carbohydrates (sugars)= #1(sugars)= #1Simple sugarsSimple sugars = =

monosaccharide (one) is monosaccharide (one) is monomermonomer

Ex: glucose, fructose = Ex: glucose, fructose = CC66HH1212OO66

Carbohyrdates = Carbohyrdates = DisaccharidesDisaccharides

• Made from joining 2 mono’s Made from joining 2 mono’s together together – Glucose + fructose = MaltoseGlucose + fructose = Maltose

° Mono + Mono = DiMono + Mono = Di° Must take out a WATER molecule (H and OH) between Must take out a WATER molecule (H and OH) between

each mono to join together to make a DIeach mono to join together to make a DI

Polysaccharides Polysaccharides (3+ monos)(3+ monos)• StorageStorage

(starch=plant, (starch=plant, glycogen=animal)glycogen=animal)

• Structural supportStructural support (cellulose, chitin)(cellulose, chitin)

Saccharide FormationSaccharide Formation• Condensation Condensation links monosaccharideslinks monosaccharides

Proteins = #2Proteins = #2• Made of C, H, O, NMade of C, H, O, N• Chains of Chains of amino acidsamino acids• A.A. A.A. = monomer= monomer• Globular shapeGlobular shape• Carbon backbone, Carbon backbone, carboxylcarboxyl,,

amineamine & a & a functionalfunctional ( (RR) group) group

Functional GroupsFunctional Groups

Protein FormationProtein Formation• Condensation Condensation makesmakes peptide bonds peptide bonds• Water is produced as a result of rxnWater is produced as a result of rxn

ProteinsProteins

• Often in complex and Often in complex and unique shapes due to H unique shapes due to H bonds, temp., solvent etcbonds, temp., solvent etc

• Are your hair,Are your hair,

Muscles, nails, Muscles, nails,

Enzymes!Enzymes!

-Function: provide -Function: provide

Protection; run chem rxnsProtection; run chem rxns

Lipids = #3 (fats, oils, and waxes)Lipids = #3 (fats, oils, and waxes)• Made of C, H, OMade of C, H, O• Made of glycerol and fatty acids (looks Made of glycerol and fatty acids (looks

like an “E” with long chains of F.A’slike an “E” with long chains of F.A’s

• Fatty acid = Fatty acid = carbon chain + carbon chain + carboxyl unitcarboxyl unit

• Types of Lipids:Types of Lipids:– PhospholipidPhospholipid= 2 fatty acids w/ one glycerol= 2 fatty acids w/ one glycerol– TriglycerideTriglyceride= 3 fatty acids combined w/ one = 3 fatty acids combined w/ one

glycerolglycerol

C C OH

O

C C CC

Lipids Lipids (fats, oils, and waxes)(fats, oils, and waxes)• LONG hydrocarbon chains, that are LONG hydrocarbon chains, that are

insoluble in waterinsoluble in water (non polar) (non polar)• Fats have Fats have 6 times more energy6 times more energy

than starch, carry more energy-rich than starch, carry more energy-rich bondsbonds

Triglycerides: Saturated Vs. Triglycerides: Saturated Vs. UnsaturatedUnsaturated

• SaturatedSaturated = single bonds ONLY in carbon chain = BAD = single bonds ONLY in carbon chain = BAD FATS….will clog up vesselsFATS….will clog up vessels– Carbons “saturated” w/ hydrogen (solid at room temp)Carbons “saturated” w/ hydrogen (solid at room temp)

• UnsaturatedUnsaturated = double or triple bonds (liquid at room = double or triple bonds (liquid at room temp)= GOOD temp)= GOOD FATS…squeeze through more easilyFATS…squeeze through more easily

UnsaturatedUnsaturatedSaturatedSaturated

SteroidsSteroids• Lipids that form into Lipids that form into 44 rings rings

– Many are Many are hormoneshormones

–Cholesterol, testosteroneCholesterol, testosterone

Nucleic Acids = Nucleic Acids = #4 #4 (DNA, RNA)(DNA, RNA)

• Nitrogenous baseNitrogenous base + + sugarsugar + + phosphatephosphate molecule molecule

• Store hereditary info.Store hereditary info.• Form the code of lifeForm the code of life• Monomer = Monomer = nucleotidenucleotide

–sugar, phosphate, basesugar, phosphate, base° L-ShapedL-Shaped

TestsTestsOrganiccompound

Reagent Positiveresult

Simple sugar BenedictsSolution

Any colorchange butblue

Starch Iodine Purple/Black

Protein Biuret Purple

Lipid Brown Paper Translucent

Activation Energy= Ch 3Activation Energy= Ch 3• Energy needed by molecules in Energy needed by molecules in

order to react order to react

–Energy needed to start a Energy needed to start a chemical rxnchemical rxn

EnzymesEnzymes

EnzymesEnzymes• Reduce amount of activation energyReduce amount of activation energy• Are biological catalysts in living things Are biological catalysts in living things

speed up chem rxns:speed up chem rxns:

– are proteinsare proteins– SpecificSpecific shape shape

– Active siteActive site: : crevice where substrate crevice where substrate

binds to enzyme duringbinds to enzyme during

a reactiona reaction

EnzymesEnzymes• Need a specific Need a specific

–TemperatureTemperature

–pHpH• Concentration of enzyme & substrate and Concentration of enzyme & substrate and

ionic conditions are importantionic conditions are important• Are Are NOTNOT consumed in rxn…are recyclable consumed in rxn…are recyclable• Is lock and key model or induced fit (into Is lock and key model or induced fit (into

active site)active site)