92
Chapter 9 Chapter 9 Photosynthesis Photosynthesis

Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Embed Size (px)

Citation preview

Page 1: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 9Chapter 9

PhotosynthesisPhotosynthesis

Page 2: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

This is CHAPTER 9 in your text…….ignore This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each the “chapter 7” title at the top of each powerpoint page. powerpoint page.

Chapter 7 2

Page 3: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 3

What Is Photosynthesis?What Is Photosynthesis?

PhotosynthesisPhotosynthesis is the ability to capture is the ability to capture sunlight energy and convert it to chemical sunlight energy and convert it to chemical energyenergy

Most forms of life on Earth depend on the Most forms of life on Earth depend on the chemical energy produced by chemical energy produced by photosynthetic organismsphotosynthetic organisms

Page 4: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 4

The Photosynthetic EquationThe Photosynthetic Equation

6CO2 carbondioxide

+ 6H2O water

+ light energy sunlight

C6H12O6

glucose (sugar)

+ 6O2

oxygen

Photosynthesis occurs in plants, algae, and Photosynthesis occurs in plants, algae, and some prokaryotessome prokaryotesPhotosynthetic organisms are Photosynthetic organisms are autotrophsautotrophs (“self- (“self-

feeders”)feeders”)Photosynthesis in plants occurs within Photosynthesis in plants occurs within chloroplastschloroplasts

Page 5: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 5

Gases, Sugar, and Water CycleGases, Sugar, and Water Cycle

Production of carbon compounds like Production of carbon compounds like glucose (photosynthesis) is linked with glucose (photosynthesis) is linked with energy extraction (in cellular respiration)energy extraction (in cellular respiration)

Water, COWater, CO22, sugar, and O, sugar, and O22 cycle between the cycle between the two processestwo processes

Photosynthesis and cellular respiration are Photosynthesis and cellular respiration are interconnectedinterconnected

Page 6: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 6Interconnections:Interconnections:Photosynthesis & RespirationPhotosynthesis & Respiration

Page 7: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 7

Adaptations for PhotosynthesisAdaptations for Photosynthesis

LeavesLeavesChloroplastsChloroplasts

Let’s look at your diagramsLet’s look at your diagrams

Page 8: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 8Structures ofStructures ofPhotosynthesisPhotosynthesis

Page 9: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 9

LeavesLeaves

Flattened leaf shape exposes large Flattened leaf shape exposes large surface area to catch sunlightsurface area to catch sunlight

Upper and lower leaf surfaces of a leaf Upper and lower leaf surfaces of a leaf comprise the comprise the epidermisepidermis

Waxy, waterproof Waxy, waterproof cuticlecuticle on outer on outer surfaces reduces water evaporationsurfaces reduces water evaporation

Page 10: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 10

Leaf AnatomyLeaf Anatomy

Adjustable pores called Adjustable pores called stomatastomata allow for allow for entry of air with COentry of air with CO22

Inner Inner mesophyllmesophyll cell layers contain cell layers contain majority of chloroplasts- many per cell majority of chloroplasts- many per cell “photosynthesis tissue”“photosynthesis tissue”

Vascular bundlesVascular bundles (veins) supply water (veins) supply water and minerals to the leaf while carrying and minerals to the leaf while carrying sugars away from the leafsugars away from the leaf

Page 11: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 11

Internal Leaf StructureInternal Leaf Structure

Internal leaf structure is crucial to Internal leaf structure is crucial to photosynthesis since photosynthesis photosynthesis since photosynthesis occurs primarily in the leaves of land occurs primarily in the leaves of land plans plans

Page 12: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 12

Leaf StructureLeaf Structure

MesophyllMesophyllCellsCells

MesophyllMesophyllCellsCells

Upper EpidermisUpper EpidermisUpper EpidermisUpper Epidermis

LowerLowerEpidermisEpidermis

LowerLowerEpidermisEpidermisVeinVeinVeinVein StomaStomaStomaStoma

Page 13: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 13

Anatomy of a ChloroplastAnatomy of a Chloroplast

Mesophyll cells have 40-200 Mesophyll cells have 40-200 chloroplasts eachchloroplasts each

Chloroplasts are bounded by a double Chloroplasts are bounded by a double membrane composed of the membrane composed of the innerinner and and outer membranesouter membranes

Page 14: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 14

Anatomy of a ChloroplastAnatomy of a Chloroplast

The The stromastroma is the semi-fluid medium within the is the semi-fluid medium within the inner membrane. Contains the enzymes needed inner membrane. Contains the enzymes needed for the reactions of photosynthesis. Location of for the reactions of photosynthesis. Location of light independent reactions of photosynthesis.light independent reactions of photosynthesis.

Disk-shaped sacs called Disk-shaped sacs called thylakoidsthylakoids found within found within the the stromastroma in stacks called in stacks called granagrana. Chlorophyll . Chlorophyll found in thylakoids. Involved in ATP synthesis or found in thylakoids. Involved in ATP synthesis or light dependent reactions of photosynthesislight dependent reactions of photosynthesis

Find these on YOUR diagramFind these on YOUR diagram

Page 15: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 15

Chloroplast StructureChloroplast Structure

Inner & OuterInner & OuterMembranesMembranes

ThylakoidsThylakoids

GranumGranum

Stroma Stroma (space)(space)

Page 16: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 16

Page 17: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

REVIEW EQUATION FOR REVIEW EQUATION FOR PHOTOSYNTHESIS:PHOTOSYNTHESIS:

Chapter 7 17

Page 18: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

End of Photosynthesis Lecture #2End of Photosynthesis Lecture #2Quiz tomorrow!!!!!Quiz tomorrow!!!!!

Chapter 7 18

Page 19: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Photosynthesis Lecture #3Photosynthesis Lecture #3Introduction to the light dependent Introduction to the light dependent reactions of photosynthesisreactions of photosynthesis

Chapter 7 19

Page 20: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

In the light dependent reactions, the radiant In the light dependent reactions, the radiant energy from sunlight is used to make ATP energy from sunlight is used to make ATP and to reduce the electron acceptor and to reduce the electron acceptor molecule NADP+, forming NADPH. The molecule NADP+, forming NADPH. The light energy captured by photosynthesis is light energy captured by photosynthesis is temporarily stored within these two temporarily stored within these two compounds.compounds.

Chapter 7 20

Page 21: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Light dependent reaction equationLight dependent reaction equation

Water + NADP+ + ADP + P yieldsWater + NADP+ + ADP + P yieldsOxygen + NADPH + ATPOxygen + NADPH + ATP

How many of each??????How many of each??????

Chapter 7 21

Page 22: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Because life on our planet depends on light, Because life on our planet depends on light, it is important to understand the nature of it is important to understand the nature of light and how it permits photosynthesis to light and how it permits photosynthesis to occuroccur

Chapter 7 22

Page 23: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Light is a very small portion of a vast, Light is a very small portion of a vast, continuous spectrum of radiation called the continuous spectrum of radiation called the electromagnetic spectrum.electromagnetic spectrum.

Light travels in wavesLight travels in wavesA wavelength is the distance from one wave peak A wavelength is the distance from one wave peak

to the nextto the nextThe different colors of light correspond to The different colors of light correspond to

different regions of the visible spectrum and are different regions of the visible spectrum and are identified by their wavelengths. Violet light has identified by their wavelengths. Violet light has the shortest wavelength and red light has the the shortest wavelength and red light has the longestlongest

Chapter 7 23

Page 24: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Colors of the visible spectrumColors of the visible spectrum

ROY G BIVROY G BIV

Chapter 7 24

Page 25: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 25

The Energy in Visible LightThe Energy in Visible Light

The sun radiates The sun radiates electromagnetic energyelectromagnetic energyPackets of energy called Packets of energy called photonsphotons have have different energy different energy

levelslevels• Short-wavelength photons are very energeticShort-wavelength photons are very energetic• Longer-wavelength photons have lower energiesLonger-wavelength photons have lower energiesEnergy of photons is inversely proportional to the Energy of photons is inversely proportional to the

wavelength of lightwavelength of light

Page 26: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 26Light, ChloroplastLight, ChloroplastPigments, & PhotosynthesisPigments, & Photosynthesis

Gamma RaysGamma Rays X-RaysX-Rays UVUV InfraredInfrared Micro-Micro-waveswaves

RadioRadioWavesWaves

Visible LightVisible Light

400400 450450 500500 550550 600600 650650 700700 750750Wavelength (nanometers, nm)Wavelength (nanometers, nm)

Page 27: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

• Photons interact with atomsPhotons interact with atoms• Raises electrons to higher energy levelsRaises electrons to higher energy levels• Excites or energizes the electronsExcites or energizes the electrons• When this occurs, one of two things can happen:When this occurs, one of two things can happen:

• Electron returns to original state and energy is Electron returns to original state and energy is lost as heat ORlost as heat OR

• The excited electron leaves the atom and is The excited electron leaves the atom and is accepted by the electron acceptor molecule. accepted by the electron acceptor molecule. (this is what occurs in Photosynthesis)(this is what occurs in Photosynthesis)

Chapter 7 27

Page 28: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

PigmentsPigments

• Pigments are substances that absorb Pigments are substances that absorb visible lightvisible light

• Different pigments absorb different Different pigments absorb different wavelengths of lightwavelengths of light

Chapter 7 28

Page 29: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 29

Light Captured by PigmentsLight Captured by Pigments

Action of light-capturing pigmentsAction of light-capturing pigments• AbsorptionAbsorption of certain wavelengths of certain wavelengths

(light is “trapped”)(light is “trapped”)• ReflectionReflection of certain wavelengths of certain wavelengths

(light bounces back). Light we see(light bounces back). Light we see• TransmissionTransmission of certain wavelengths of certain wavelengths

(light passes through)(light passes through)

Page 30: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 30

Light Captured by PigmentsLight Captured by Pigments

Absorbed light drives biological processes Absorbed light drives biological processes when it is converted to chemical energywhen it is converted to chemical energy

Common pigments found in chloroplasts Common pigments found in chloroplasts include:include:• ChlorophyllChlorophyll aa andand b- absorbs light in the b- absorbs light in the

blue and red regions. Green NOT absorbedblue and red regions. Green NOT absorbed• Accessory pigments such as Accessory pigments such as carotenoids- carotenoids-

yellow and orangeyellow and orange

Page 31: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 31

Light Captured by PigmentsLight Captured by Pigments

Chlorophyll a and bChlorophyll a and b absorb violet, blue, absorb violet, blue, and red light but reflect green light and red light but reflect green light (hence they appear green)(hence they appear green)

CarotenoidsCarotenoids absorb blue and green light absorb blue and green light but reflect yellow, orange, or red (hence but reflect yellow, orange, or red (hence they appear yellow-orange)they appear yellow-orange)

Pigment absorbs visible lightPigment absorbs visible light

Page 32: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 32

00

2020

4040

6060

8080

100100

% L

ight

Abs

orpt

ion

% L

ight

Abs

orpt

ion

400400 450450 500500 550550 600600 650650 700700 750750Wavelength (nanometers)Wavelength (nanometers)

400400 450450 500500 550550 600600 650650 700700 750750

Absorption SpectraAbsorption Spectra

Visible LightVisible Light

ChlorophyllChlorophyll

CarotenoidsCarotenoids

PhycocyaninPhycocyanin

CollectivelyCollectively

Chapter 7 8Light, ChloroplastLight, ChloroplastPigments & PhotosynthesisPigments & Photosynthesis

Gamma RaysGamma Rays XX-- RaysRays UVUV InfraredInfrared MicroMicro--waveswaves

RadioRadioWavesWaves

Visible LightVisible Light

400400 400400 400400 400400 400400 400400 400400 400400Wavelength (nanometers)Wavelength (nanometers)

Page 33: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

QuestionQuestion

Why do leaves “change color” in the fall??Why do leaves “change color” in the fall??

Chapter 7 33

Page 34: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

AnswerAnswer

Leaves change color due to a lack of chlorophyll. Chlorophyll is used in photosynthesis and gives leaves their green color. As the days shorten, trees stop producing chlorophyll, allowing other pigments to take over

Chapter 7 34

Page 35: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

ChromatographyChromatography

Activity completed hereActivity completed here

Chapter 7 35

Page 36: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Lecture #4Lecture #4Light Dependent Reactions of Light Dependent Reactions of PhotosynthesisPhotosynthesis

Chapter 7 36

Page 37: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 37

GlucoseGlucose

OO22

Overview of PhotosynthesisOverview of Photosynthesis

Light-DependentLight-DependentReactionsReactions

(in thylakoids)(in thylakoids)

Light-IndependentLight-IndependentReactionsReactions

(in stroma)(in stroma)

DepletedDepletedCarriersCarriers

(ADP, NADP(ADP, NADP++))

DepletedDepletedCarriersCarriers

(ADP, NADP(ADP, NADP++))

EnergizedEnergizedCarriersCarriers

(ATP, NADPH)(ATP, NADPH)

HH22OO

COCO22

Page 38: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

2 phases of photosynthesis2 phases of photosynthesis

Photosynthesis happens in two phases:Photosynthesis happens in two phases:1.1. the light dependent reactions which the light dependent reactions which convert light energy into chemical energy convert light energy into chemical energy (produces ATP)(produces ATP)2.2. the light independent reactions- the light independent reactions- produce simple sugars from the ATP of the produce simple sugars from the ATP of the light dependent reactionslight dependent reactions

Chapter 7 38

Page 39: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Light dependent reactionsLight dependent reactions

• OVERVIEW:OVERVIEW:• Occurs in thylakoid membranes of Occurs in thylakoid membranes of

chloroplastchloroplast• Requires sunlight and waterRequires sunlight and water• Includes photosystems II and I and the Includes photosystems II and I and the

electron transport chainelectron transport chain• End products are ATP, NADPH, and End products are ATP, NADPH, and

oxygenoxygen

Chapter 7 39

Page 40: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

NADPHNADPH

Nicotinamide adenine dinucleotide Nicotinamide adenine dinucleotide phosphatephosphate

Energy storage compound similar to ATPEnergy storage compound similar to ATP““electron acceptor”electron acceptor”Donates electrons for use in the Calvin Donates electrons for use in the Calvin Cycle (light independent reactions, or Cycle (light independent reactions, or “dark” reactions)“dark” reactions)

Chapter 7 40

Page 41: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 41The PhotosystemsThe Photosystems

Page 42: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 42

Light-Dependent ReactionsLight-Dependent Reactions

Steps of the light reactions: Steps of the light reactions: PHOTOSYSTEM IIPHOTOSYSTEM II

Accessory pigments in Photosystems Accessory pigments in Photosystems absorb light and pass the energy of absorb light and pass the energy of the light to the light to reaction centersreaction centers containing containing chlorophyllchlorophyll

Reaction centers receive energized Reaction centers receive energized electrons…electrons…

Page 43: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 43

Light-Dependent ReactionsLight-Dependent Reactions

Energized electrons then passed down a Energized electrons then passed down a series of electron carrier molecules series of electron carrier molecules ((Electron Transport ChainElectron Transport Chain). The ETC is a ). The ETC is a series of proteins embedded in the series of proteins embedded in the thylakoid membrane. Page 226thylakoid membrane. Page 226

Energy released from passed electrons used Energy released from passed electrons used to synthesize to synthesize ATPATP from ADP and from ADP and phosphatephosphate

Page 44: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 44

Page 45: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

• After the electrons have traveled down After the electrons have traveled down the ETC, they are re-energized in a the ETC, they are re-energized in a second photosystem and passed down a second photosystem and passed down a second ETCsecond ETC

• Second photosystem is named Second photosystem is named PHOTOSYSTEM I PHOTOSYSTEM I

Chapter 7 45

Page 46: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

PHOTOSYSTEM IPHOTOSYSTEM I

• At the bottom of this second ETC, the electrons are At the bottom of this second ETC, the electrons are still very energizedstill very energized

• The electrons are transferred to the stroma of the The electrons are transferred to the stroma of the chloroplast by an electron carrier molecule called chloroplast by an electron carrier molecule called NADP+NADP+

• NAPH+ combines with two electrons and one H+ to NAPH+ combines with two electrons and one H+ to become NADPHbecome NADPH

• NADPH stores the energy- does not use it. Energy NADPH stores the energy- does not use it. Energy will be used in the light independent reactionswill be used in the light independent reactions

Chapter 7 46

Page 47: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Steps (summary)Steps (summary)

Photosystem IIPhotosystem II1.1. Water and light inWater and light in2.2. Energized electrons (energy) passed to reaction centers containing chlorophyllEnergized electrons (energy) passed to reaction centers containing chlorophyll3.3. Oxygen releasedOxygen released4.4. Electron transport chain- proteins pass along electrons of H+Electron transport chain- proteins pass along electrons of H+

*#3 and #4 are known as PHOTOLYSIS when two molecules of water are split to form *#3 and #4 are known as PHOTOLYSIS when two molecules of water are split to form oxygen, H+, and electrons)oxygen, H+, and electrons)

Photosystem IPhotosystem I5. Light absorbed5. Light absorbed6. 26. 2ndnd ETC of H+ ETC of H+7.7. NADPH created in stromaNADPH created in stroma8.8. ATP synthetase creates ATP “Photophosphorylation”ATP synthetase creates ATP “Photophosphorylation”

NADPH and ATP fuel Calvin Cycle (otherwise known as light INDEPENDENT reaction)NADPH and ATP fuel Calvin Cycle (otherwise known as light INDEPENDENT reaction)

Chapter 7 47

Page 48: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 48Thylakoid Structure & Thylakoid Structure & Light-Dependent ReactionsLight-Dependent Reactions

Page 49: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 49

Page 50: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

End lecture hereEnd lecture here

Chapter 7 50

Page 51: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

PHOTOLYSISPHOTOLYSIS

• Reaction taking place in the thylakoid Reaction taking place in the thylakoid membranes of a chloroplast during light membranes of a chloroplast during light dependent reactions where two dependent reactions where two molecules of water are split to form molecules of water are split to form oxygen, hydrogen ions, and electronsoxygen, hydrogen ions, and electrons

Chapter 7 51

Page 52: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

PHOTOLYSISPHOTOLYSIS

• Replaces the electrons lost at the Replaces the electrons lost at the beginning of photosystem II (first beginning of photosystem II (first photosystem)photosystem)

• Does this so chlorophyll can absorb Does this so chlorophyll can absorb additional light and continue producing additional light and continue producing ATPATP

• Figure 9.6 page 228Figure 9.6 page 228

Chapter 7 52

Page 53: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

PHOTOLYSIS PHOTOLYSIS

• Equation page 228. Equation page 228. • KNOW itKNOW it

Chapter 7 53

Page 54: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

PHOTOLYSISPHOTOLYSIS

• Products:Products:• ½ molecule of oxygen½ molecule of oxygen• Two electronsTwo electrons• Two hydrogen ionsTwo hydrogen ions

Chapter 7 54

Page 55: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

PhotolysisPhotolysis

• Oxygen is released into the airOxygen is released into the air• Electrons are returned to chlorophyllElectrons are returned to chlorophyll• Hydrogen ions are pumped into thylakoid Hydrogen ions are pumped into thylakoid

where they accumulate high where they accumulate high concentrationconcentration

Chapter 7 55

Page 56: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 56

Oxygen as a By-productOxygen as a By-product

Page 57: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chemiosmosis (2011-skip)Chemiosmosis (2011-skip)

• DEFINITION:DEFINITION:• Because there is a difference in Because there is a difference in

concentration of H+ on either side of the concentration of H+ on either side of the thylakoid membrane (creates a thylakoid membrane (creates a concentration gradient), ions diffuse out concentration gradient), ions diffuse out of the thylakoid and provide energy for of the thylakoid and provide energy for the production of ATP.the production of ATP.

• Page 228Page 228

Chapter 7 57

Page 58: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 58Chemiosmosis 1Chemiosmosis 1

Page 59: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 59

Chemiosmosis 2Chemiosmosis 2

Page 60: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chemiosmosis animationChemiosmosis animation

http://www.youtube.com/watch?v=jHvXfplbS9Y

http://www.youtube.com/watch?v=E_XQR800AgM

Chapter 7 60

Page 61: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

LIGHT INDEPENDENT REACTIONSLIGHT INDEPENDENT REACTIONSLecture #5Lecture #5

Chapter 7 61

Page 62: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Light Independent ReactionsLight Independent Reactions

OVERVIEWOVERVIEW• occurs in stroma (liquid portion of occurs in stroma (liquid portion of

chloroplast)chloroplast)• Involves the Calvin Cycle and carbon Involves the Calvin Cycle and carbon

fixationfixation• Sometimes referred to as “dark reaction”Sometimes referred to as “dark reaction”• Reactants- ATP, NADPH, carbon dioxideReactants- ATP, NADPH, carbon dioxide• End product- glucose End product- glucose

Chapter 7 62

Page 63: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 63

Light-Light-InIndependent Reactionsdependent Reactions

NADPH and ATP from light-dependent NADPH and ATP from light-dependent reactions used to power glucose reactions used to power glucose synthesissynthesis

Light not Light not directlydirectly necessary for light- necessary for light-independent reactions if ATP & NADPH independent reactions if ATP & NADPH availableavailable

Light-independent reactions called the Light-independent reactions called the Calvin-BensonCalvin-Benson CycleCycle or or CC33 Cycle Cycle

Page 64: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 64

The CThe C33 Cycle Cycle

6 CO6 CO22 used to synthesize 1 glucose used to synthesize 1 glucose (C(C66HH1212OO66))

Carbon dioxide is captured and linked to Carbon dioxide is captured and linked to ribulose bisphosphate (RuBP)ribulose bisphosphate (RuBP)

ATP and NADPH from light dependent ATP and NADPH from light dependent reactions used to power Creactions used to power C33 reactions reactions

Page 65: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Page 229 in your textPage 229 in your text

The calvin cycle takes the carbon in carbon The calvin cycle takes the carbon in carbon dioxide, adds it to one molecule of RuBP dioxide, adds it to one molecule of RuBP and forms sugars through a series of and forms sugars through a series of reactions in the stroma of chloroplasts. reactions in the stroma of chloroplasts. The NADPH and ATP produced during the The NADPH and ATP produced during the earlier light dependent reactions are earlier light dependent reactions are important molecules for this series of important molecules for this series of reactions.reactions.

Chapter 7 65

Page 66: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Question:Question:

Why is the calvin cycle in plants directly Why is the calvin cycle in plants directly and indirectly important to animals?and indirectly important to animals?

Chapter 7 66

Page 67: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Preview videoPreview video

http://www.youtube.com/watch?v=mYbMPwmwx88

Chapter 7 67

Page 68: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 68

CC33 Cycle Has Five Parts pg 229 Cycle Has Five Parts pg 229

1. Carbon fixation (carbon capture)1. Carbon fixation (carbon capture)• Carbon atom from carbon dioxide bonds Carbon atom from carbon dioxide bonds

with a five carbon sugar called ribulose with a five carbon sugar called ribulose biphosphate (RuBP) to form an unstable 6 biphosphate (RuBP) to form an unstable 6 carbon sugar. (six RuBP plus 6 CO2)carbon sugar. (six RuBP plus 6 CO2)

•Think of RuBP as carbonThink of RuBP as carbon dioxide dioxide acceptorsacceptors

Page 69: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Formation of three carbon Formation of three carbon moleculesmolecules

Step #2Step #2The six carbon sugar formed in step 1 immediately The six carbon sugar formed in step 1 immediately

splits to form two three carbon molecules called PGAsplits to form two three carbon molecules called PGA

Chapter 7 69

Page 70: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Use of ATP and NADPHUse of ATP and NADPH

Step #3Step #3A series of NADPH and ATP from the light A series of NADPH and ATP from the light dependent reactions converts the three dependent reactions converts the three carbon molecules into PGAL carbon molecules into PGAL (phosphoglyceraldehyde) which are 3 (phosphoglyceraldehyde) which are 3 carbon sugars with higher energy levelscarbon sugars with higher energy levels

Chapter 7 70

Page 71: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Sugar productionSugar production

Step 4Step 4One out of every six molecules of PGAL is One out of every six molecules of PGAL is transferred to the cytoplasm and used in transferred to the cytoplasm and used in the synthesis of sugars and other the synthesis of sugars and other carbohydrates. After THREE rounds of the carbohydrates. After THREE rounds of the cycle, (each round fixing one molecule of cycle, (each round fixing one molecule of CO2) CO2) six molecules of PGAL are produced.six molecules of PGAL are produced.

Chapter 7 71

Page 72: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

RuBP is replenishedRuBP is replenished

Step 5Step 5Five molecules of PGAL, each with 3 carbon Five molecules of PGAL, each with 3 carbon atoms, produce three molecules of the five atoms, produce three molecules of the five carbon RuBP. This requires three more carbon RuBP. This requires three more ATP. This replenishes the RuBP that was ATP. This replenishes the RuBP that was used up, and the cycle can continue. The used up, and the cycle can continue. The 66thth molecule of PGAL is available to the molecule of PGAL is available to the organism to make sugar.organism to make sugar.

Chapter 7 72

Page 73: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

• The PGAL that leaves the calvin cycle The PGAL that leaves the calvin cycle leaves the chloroplast and goes into the leaves the chloroplast and goes into the cytoplasmcytoplasm

• This PGAL can combine with another This PGAL can combine with another PGAL to form a 6 carbon sugar moleculePGAL to form a 6 carbon sugar molecule

• C6H12O6C6H12O6

Chapter 7 73

Page 74: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

In summary, the imputs required for the In summary, the imputs required for the light independent reactions are 6 light independent reactions are 6 molecules of CO2, hydrogen from NADPH, molecules of CO2, hydrogen from NADPH, and ATP. In the end, the six carbons from and ATP. In the end, the six carbons from the CO2 can be accounted for by the the CO2 can be accounted for by the harvest of a six carbon molecule. The harvest of a six carbon molecule. The remaining PGAL molecules are used to remaining PGAL molecules are used to synthesize the RuBP molecules with which synthesize the RuBP molecules with which more CO2 molecules may combine.more CO2 molecules may combine.

Chapter 7 74

Page 75: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Calvin cycle animationCalvin cycle animation

http://www.youtube.com/watch?v=_NIhg1qa_L0

Chapter 7 75

Page 76: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Calvin cycle songCalvin cycle song

http://www.youtube.com/watch?v=_GpGGHGG6TU&feature=related

Chapter 7 76

Page 77: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 77

Relationship Between ReactionsRelationship Between Reactions

The “photo” part of photosynthesis The “photo” part of photosynthesis refers to the capture of light energy refers to the capture of light energy (light dependent reactions)(light dependent reactions)

The “synthesis” part of photosynthesis The “synthesis” part of photosynthesis refers to glucose synthesis (light-refers to glucose synthesis (light-inindependent reactions)dependent reactions)

Page 78: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 78

Relationship Between ReactionsRelationship Between Reactions

Light dependent reactions produce ATP Light dependent reactions produce ATP and NADPH which is used to drive and NADPH which is used to drive light-independent reactionslight-independent reactions

Depleted carriers (ADP and NADPDepleted carriers (ADP and NADP++) ) return to light-dependent reactions for return to light-dependent reactions for rechargingrecharging

Page 79: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 79

A Summary of PhotosynthesisA Summary of Photosynthesis

Light-dependent Light-dependent reactions occur reactions occur

in thylakoidsin thylakoids Light-Light-independent independent reactions (creactions (c33

cycle) occur in cycle) occur in stromastroma

Page 80: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 80

Page 81: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Lecture #6Lecture #6C3 and C4 plants and photorespirationC3 and C4 plants and photorespiration

Chapter 7 81

Page 82: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 82

Water, COWater, CO22, and the C, and the C44 Pathway Pathway

The ideal leaf:The ideal leaf:• has large surface area to intercept sunlighthas large surface area to intercept sunlight• are porous to allow for COare porous to allow for CO22 entry from air entry from air

Problem: Substantial leaf porosity leads to Problem: Substantial leaf porosity leads to substantial water evaporation, causing substantial water evaporation, causing dehydration stress on the plantdehydration stress on the plant

Plants evolved waterproof coating and Plants evolved waterproof coating and adjustable pores (stomata) for COadjustable pores (stomata) for CO22 entry entry

Page 83: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 83

When Stomata Are ClosedWhen Stomata Are Closed

When stomata close, COWhen stomata close, CO22 levels drop and O levels drop and O22 levels riselevels rise

Carbon fixing enzyme combines OCarbon fixing enzyme combines O22 instead of instead of COCO22 with RuBP (called with RuBP (called photorespirationphotorespiration))

Photorespiration:Photorespiration:• OO22 is used up as CO is used up as CO22 is generated is generated• No useful cellular energy madeNo useful cellular energy made• No glucose producedNo glucose produced• Photorespiration is unproductive and Photorespiration is unproductive and

wastefulwasteful

Page 84: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 84

When Stomata Are ClosedWhen Stomata Are Closed

Hot, dry weather causes stomata to stay Hot, dry weather causes stomata to stay closedclosed

Oxygen levels rise as carbon dioxide levels Oxygen levels rise as carbon dioxide levels fall inside leaffall inside leaf

Photorespiration very common under such Photorespiration very common under such conditionsconditions

Plants may die from lack of glucose Plants may die from lack of glucose synthesissynthesis

Page 85: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 85

CC44 Plants Reduce Photorespiration Plants Reduce Photorespiration

““CC44 plants” have chloroplasts in bundle plants” have chloroplasts in bundle sheath cells as well as mesophyll cellssheath cells as well as mesophyll cells• Bundle sheath cells surround vascular Bundle sheath cells surround vascular

bundles deep within mesophyllbundles deep within mesophyll• CC33 plants lack bundle sheath cell plants lack bundle sheath cell

chloroplastschloroplasts

Page 86: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 86

CC33 Plants & the Pathway Plants & the PathwayCC33 plants use the C plants use the C33

pathwaypathway

In a CIn a C33 plant, most plant, most chloroplasts are in chloroplasts are in

mesophyll cells.mesophyll cells.

Page 87: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 87

CC33 Plants & the Pathway Plants & the Pathway

Much photorespiration Much photorespiration occurs under hot, dry occurs under hot, dry

conditionsconditions

Page 88: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 88CC44 Plants & the C Plants & the C4 4 PathwayPathway

CC44 plants use the C plants use the C44 pathwaypathway

In a CIn a C44 plant, both plant, both mesophyll & bundle-mesophyll & bundle-sheath cells contain sheath cells contain

chloroplasts.chloroplasts.

Page 89: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7 89

CC44 Plants & the Plants & the CC4 4 PathwayPathway

Almost no Almost no photorespiration photorespiration occurs under hot, occurs under hot,

dry conditions.dry conditions.

COCO22 is captured is captured with a highly with a highly

specific enzyme.specific enzyme.

Much glucose Much glucose synthesis occurs.synthesis occurs.

Mesophyll cell in a CMesophyll cell in a C44 plant plant

Bundle-sheath cell in a CBundle-sheath cell in a C44 plant plant

Page 90: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Photosynthesis songPhotosynthesis song

http://www.youtube.com/watch?v=Q_1mxZdF2TY

Chapter 7 90

Page 91: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Bozeman Biology PhotosynthesisBozeman Biology Photosynthesis

http://www.youtube.com/watch?v=_wO9f3ER17M

Chapter 7 91

Page 92: Chapter 9 Photosynthesis. This is CHAPTER 9 in your text…….ignore the “chapter 7” title at the top of each powerpoint page. Chapter 7 2

Chapter 7Chapter 7

The endThe end