PowerPoint Presentation

PhotosynthesisLife Is Solar Powered!What Would Plants Look Like On Alien Planets?

Why Would They Look Different?Different Stars Give off Different types of light or Electromagnetic WavesThe color of plants depends on the spectrum of the stars light, which astronomers can easily observe. (Our Sun is a type G star.)

Anatomy of a WaveWavelengthIs the distance between the crests of wavesDetermines the type of electromagnetic energy

Electromagnetic Spectrum Is the entire range of electromagnetic energy, or radiationThe longer the wavelength the lower the energy associated with the wave.

Visible LightLight is a form of electromagnetic energy, which travels in waves

When white light passes through a prism the individual wavelengths are separated out.

Visible Light SpectrumLight travels in wavesLight is a form of radiant energyRadiant energy is made of tiny packets of energy called photonsThe red end of the spectrum has the lowest energy (longer wavelength) while the blue end is the highest energy (shorter wavelength).The order of visible light is ROY-G-BIVThis is the same order you will see in a rainbow b/c water droplets in the air act as tiny prisms

Chloroplast Where the Magic Happens!H2OCO2O2C6H12O6

Light ReactionDark ReactionLight is AdsorbedBy ChlorophyllWhich splitswaterChloroplast

ATP andNADPH2ADPNADPCalvin CycleEnergyUsed Energy and is recycled.++6 CO2 + 12 H2O + Light energy C6H12O6 + 6 O2 + 6 H2 O Light Options When It Strikes A LeafReflect a small amount of light is reflected off of the leaf. Most leaves reflect the color green, which means that it absorbs all of the other colors or wavelengths.Absorbed most of the light is absorbed by plants providing the energy needed for the production of Glucose (photosynthesis)Transmitted some light passes through the leaf

LightReflectedLight ChloroplastAbsorbedlight GranumTransmittedlight Figure 10.7Photosynthesis OverviewPhotosynthesisincludesofoccur inoccurs inusesto produceto produceusesLightdependentreactionsThylakoidmembranesStromaNADPHATPLight EnergyATPNADPHO2ChloroplastsGlucoseLightindependentreactionsConcept MapAnatomy of a Leaf

VeinLeaf cross sectionFigure 10.3MesophyllCO2O2Stomata

Chloroplast

ChloroplastMesophyll5 mOutermembraneIntermembranespaceInnermembraneThylakoidspaceThylakoidGranumStroma1 mChloroplastAre located within the palisade layer of the leafStacks of membrane sacs called ThylakoidsContain pigments on the surfacePigments absorb certain wavelenghts of lightA Stack of Thylakoids is called a GranumPigmentsAre molecules that absorb lightChlorophyll, a green pigment, is the primary absorber for photosynthesisThere are two types of cholorophyllChlorophyll aChlorophyll bCarotenoids, yellow & orange pigments, are those that produce fall colors. Lots of Vitamin A for your eyes!Chlorophyll is so abundant that the other pigments are not visible so the plant is greenThen why do leaves change color in the fall?Color ChangeIn the fall when the temperature drops plants stop making Chrlorophyll and the Carotenoids and other pigments are left over (thats why leaves change color in the fall).

The absorption spectra of three types of pigments in chloroplasts Three different experiments helped reveal which wavelengths of light are photosynthetically important. The results are shown below.EXPERIMENTRESULTS

Absorption of light bychloroplast pigmentsChlorophyll a(a) Absorption spectra. The three curves show the wavelengths of light best absorbed by three types of chloroplast pigments.Wavelength of light (nm)Chlorophyll bCarotenoidsFigure 10.9The action spectrum of a pigmentProfiles the relative effectiveness of different wavelengths of radiation in driving photosynthesis

Rate of photosynthesis(measured by O2 release)Action spectrum. This graph plots the rate of photosynthesis versus wavelength. The resulting action spectrum resembles the absorption spectrum for chlorophyll a but does not match exactly (see part a). This is partly due to the absorption of light by accessory pigments such as chlorophyll b and carotenoids.(b)The action spectrum for photosynthesisWas first demonstrated by Theodor W. Engelmann

400500600700Aerobic bacteriaFilamentof algaEngelmanns experiment. In 1883, Theodor W. Engelmann illuminated a filamentous alga with light that had been passed through a prism, exposing different segments of the alga to different wavelengths. He used aerobic bacteria, which concentrate near an oxygen source, to determine which segments of the alga were releasing the most O2 and thus photosynthesizing most.Bacteria congregated in greatest numbers around the parts of the alga illuminated with violet-blue or red light. Notice the close match of the bacterial distribution to the action spectrum in part b.(c) Light in the violet-blue and red portions of the spectrum are most effective in driving photosynthesis.CONCLUSIONAbsorption of chlorophylls a and b at various wavelengths in the visible light spectrum

PigmentMolecules that absorb specific wavelengths of lightChlorophyll absorbs reds & blues and reflects greenXanthophyll absorbs red, blues, greens & reflects yellowCarotenoids reflect orange

ChlorophyllGreen pigment in plantsTraps suns energySunlight energizes electron in chlorophyll

PHOTOSYNTHESISComes from Greek Word photo meaning Light and syntithenai meaning to put togetherPhotosynthesis puts together sugar molecules using water, carbon dioxide, & energy from light.

Happens in two phasesLight-Dependent ReactionConverts light energy into chemical energyLight-Independent ReactionProduces simple sugars (glucose)General Equation6 CO2 + 6 H2O C6H12O6 + 6 O2

First PhaseRequires Light = Light Dependent ReactionSuns energy energizes an electron in chlorophyll moleculeElectron is passed to nearby protein molecules in the thylakoid membrane of the chloroplastExcitation of Chlorophyll by LightWhen a pigment absorbs lightIt goes from a ground state to an excited state, which is unstable

ExcitedstateEnergy of electionHeatPhoton(fluorescence)ChlorophyllmoleculeGroundstatePhotoneFigure 10.11 ATwo PhotosystemsPhotosystem II: Clusters of pigments boost e- by absorbing light w/ wavelength of ~680 nmPhotosystem I: Clusters boost e- by absorbing light w/ wavelength of ~760 nm.Reaction Center: Both PS have it. Energy is passed to a special Chlorophyll a molecule which boosts an e-A mechanical analogy for the light reactions

MillmakesATPATPeeeeePhotonPhotosystem IIPhotosystem IeeNADPHPhotonFigure 10.14ATPAdenosine TriphosphateStores energy in high energy bonds between phosphates

NADPHMade from NADP+; electrons and hydrogen ionsMade during light reactionStores high energy electrons for use during light-Independent reaction (Calvin Cycle)

H2OCO2LightLIGHT REACTIONSCALVINCYCLEChloroplast[CH2O](sugar)NADPHNADP ADP+ PO2Figure 10.5ATPPART IILIGHT INDEPENDENT REACTIONAlso called the Calvin CycleNo Light RequiredTakes place in the stroma of the chloroplastTakes carbon dioxide & converts into sugarIt is a cycle because it ends with a chemical used in the first stepBegins & EndsThe Calvin Cycle begins with the products of the light reaction.(the Calvin Cycle uses ATP & NADPH)

CO2 is added and ends in the production of sugar (GLUCOSE)

Formula: C6H12O6

The Calvin cycle(G3P)

Input(Entering oneat a time)CO23RubiscoShort-livedintermediate3 PP3 PPRibulose bisphosphate(RuBP)P3-PhosphoglycerateP6 P61,3-Bisphoglycerate6 NADPH6 NADPH+6 PP6Glyceraldehyde-3-phosphate(G3P)6 ATP3 ATP3 ADPCALVINCYCLEP5P1G3P(a sugar)OutputLightH2OCO2LIGHTREACTIONATPNADPHNADP+ADP[CH2O] (sugar)CALVINCYCLEFigure 10.18O26 ADPGlucose andother organiccompoundsPhase 1: Carbon fixationPhase 2:ReductionPhase 3:Regeneration ofthe CO2 acceptor(RuBP)Chloroplast Where the Magic Happens!H2OCO2O2C6H12O6

Light ReactionDark ReactionLight is AdsorbedBy ChlorophyllWhich splitswaterChloroplast

ATP andNADPH2ADPNADPCalvin CycleEnergyUsed Energy and is recycled.++6 CO2 + 12 H2O + Light energy C6H12O6 + 6 O2 + 6 H2 O Cellular Respiration

How Cells Harvest Chemical Energy

Introduction to Cell Metabolism

Glycolysis

Aerobic Cell Respiration

Anaerobic Cell Respiration

O2CO2BREATHINGLungsCO2O2BloodstreamMuscle cells carrying outCELLULAR RESPIRATIONSugar + O2 ATP + CO2 + H2OBreathing and Cell Respiration are related

GlucoseOxygen gasCarbon dioxideWaterEnergyCellular Respiration uses oxygen and glucose to produce Carbon dioxide, water, and ATP.

Burning glucose in an experimentEnergy released from glucose (as heat and light)100%Energy released from glucose banked in ATPBurning glucosein cellular respirationAbout 40%Gasoline energy converted to movementBurning gasolinein an auto engine25%How efficient is cell respiration?

Loss of hydrogen atomsGlucoseGain of hydrogen atomsEnergyReduction and Oxidation

OILRIG

Oxidation is losing electrons

Reduction is gaining electronsGlucose gives off energy and is oxidizedGeneral Outline GlucosePyruvic Acid GlycolysisOxygenAerobicNo OxygenAnaerobicTransition ReactionKrebs CycleETS36 ATPFermentationGlycolysis

Where? The cytosol

What? Breaks down glucose to pyruvic acid

Glycolysis

Steps A fuelmolecule is energized,using ATP.131GlucoseStep234Glucose-6-phosphateFructose-6-phosphateGlyceraldehyde-3-phosphate (G3P)Step A six-carbonintermediate splits into two three-carbon intermediates.4Step A redoxreaction generatesNADH.551,3-Diphosphoglyceric acid(2 molecules)6Steps ATPand pyruvic acidare produced.693-Phosphoglyceric acid(2 molecules)72-Phosphoglyceric acid(2 molecules)82-Phosphoglyceric acid(2 molecules)9(2 moleculesper glucose molecule)Pyruvic acidFructose-1,6-diphosphateEnergy In: 2 ATPEnergy Out: 4 ATPNET 2 ATPGeneral Outline of Aerobic Respiration Glycolysis

Krebs CycleElectron Transport SystemTransition ReactionTransition Reaction

Each pyruvic acid molecule is broken down to form CO2 and a two-carbon acetyl group, which enters the Krebs cycleAcetyl CoAPyruvic AcidGeneral Outline of Aerobic Respiration Glycolysis

Krebs CycleElectron Transport SystemTransition Reaction

Krebs Cycle

Where? In the Mitochondria

What? Uses Acetyl Co-A to generate ATP, NADH, FADH2, and CO2.

Krebs Cycle

Krebs Cycle

General Outline of Aerobic Respiration Glycolysis

Krebs CycleElectron Transport System

Electron Transport System

Figure 6.12IntermembranespaceInnermitochondrialmembraneMitochondrialmatrixProteincomplexElectroncarrierElectronflowELECTRON TRANSPORT CHAINATP SYNTHASEElectron Transport SystemFor each glucose molecule that enters cellular respiration, chemiosmosis produces up to 38 ATP molecules

Overview of Aerobic Respiration

FermentationRequires NADH generated by glycolysis.Where do you suppose these reactions take place?Yeast produce carbon dioxide and ethanolMuscle cells produce lactic acidOnly a few ATP are produced per glucoseFermentation

Fermentation When oxygen is not present, fermentation follows glycolysis, regenerating NAD+ needed for glycolysis to continue.Lactic Acid Fermentation In lactic acid fermentation, pyruvate is converted to lactate.

Fermentation in the Absence of Oxygen

Each molecule of glucose can generate 36-38 molecules of ATP in aerobic respiration but only 2 ATP molecules in respiration without oxygen (through glycolysis and fermentation).