Photosynthesis Chapter 8. Photosynthesis Reaction 6CO 2 + 6H 2 0 + light = C 6 H 12 O 6 + 6O 2 Photosynthesis uses energy from the sun to convert.

PhotosynthesisPhotosynthesisChapter 8Chapter 8

PhotosynthesisPhotosynthesis

ReactionReaction 6CO6CO2 2 + 6H+ 6H220 + light = C0 + light = C66HH1212OO6 6 + 6O+ 6O2 2

Photosynthesis uses energy from the sun Photosynthesis uses energy from the sun to convert water and COto convert water and CO22 into O into O22 and and

high-energy sugarshigh-energy sugars Occurs in the chloroplastsOccurs in the chloroplasts

CHLOROPLAST CONTENTSCHLOROPLAST CONTENTS

chloroplasts contain chloroplasts contain grana grana (stacked plates)(stacked plates) grana made of grana made of thylakoidsthylakoids (flat plates) (flat plates) colorless substance between thylakoids is colorless substance between thylakoids is

stromastroma

ChlorophyllChlorophyll Pigment made by chloroplastsPigment made by chloroplasts Absorbs the sun’s energyAbsorbs the sun’s energy

Where do the Where do the “ingredients” come “ingredients” come from?from?

Water– rootsWater– roots

COCO22– into stomata from air– into stomata from air

Energy– from sunEnergy– from sun

6CO6CO2 2 + 6H+ 6H220 + light = C0 + light = C66HH1212OO66 + 6O + 6O22

ChloroplastChloroplast

In plant cells ONLYIn plant cells ONLY Contains chlorophyll, which makes it Contains chlorophyll, which makes it

greengreen Thylakoid, grana, stromaThylakoid, grana, stroma

Electromagnetic Electromagnetic SpectrumSpectrum

Electromagnetic Electromagnetic SpectrumSpectrum

ABSORPTION SPECTRUMABSORPTION SPECTRUM

RED/ORANGE, BLUE, VIOLET RED/ORANGE, BLUE, VIOLET RESPONSIBLE FOR RESPONSIBLE FOR PHOTOSYNTHESISPHOTOSYNTHESIS

CHLOROPHYLL DOES NOT ABSORB CHLOROPHYLL DOES NOT ABSORB GREEN= WHY PLANTS ARE GREENGREEN= WHY PLANTS ARE GREEN

ONLY 1% OF SUNLIGHT IS USED IN ONLY 1% OF SUNLIGHT IS USED IN PHOTOSYNTHESISPHOTOSYNTHESIS

Leaf PigmentsLeaf Pigments

Leaves contain chlorophyll, carotenoid Leaves contain chlorophyll, carotenoid (yellow & orange), and anthocyanin (reds (yellow & orange), and anthocyanin (reds & purples) pigments.& purples) pigments.

Paper ChromatographyPaper Chromatography

Observe the different pigments in a green Observe the different pigments in a green leaf.leaf.

Chromatography aniChromatography animationmation

PHOTOSYNTHESISPHOTOSYNTHESIS

3 main events of photosynthesis:3 main events of photosynthesis: 1) absorption of light energy1) absorption of light energy 2) conversion of light energy into chemical 2) conversion of light energy into chemical

energyenergy 3) storage of chemical energy in sugars3) storage of chemical energy in sugars

6CO6CO22 + 6H + 6H220 + light = C0 + light = C66HH1212OO66 + 6O + 6O22

AN OVERVIEWAN OVERVIEW

PhotosynthesisPhotosynthesis

Light Reaction: ThylakoidLight Reaction: Thylakoid Dark Reaction (Calvin Cycle): StromaDark Reaction (Calvin Cycle): Stroma

PhotosystemsPhotosystems

Clusters in thylakoids that contain Clusters in thylakoids that contain chlorophyllchlorophyll

BIOCHEMISTRY OF BIOCHEMISTRY OF PHOTOSYNTHESIS: PHOTOSYNTHESIS: LIGHT REACTIONLIGHT REACTION

Light Reaction- in thylakoidLight Reaction- in thylakoid 1) Light absorbed by chlorophyll pigments 1) Light absorbed by chlorophyll pigments

in in photosystem IIphotosystem II… excites electrons… … excites electrons… electrons move down electrons move down electron transport electron transport chainchain toto photosystem Iphotosystem I

HH22O helps this happenO helps this happen Energy carriers- ATP & NADPH carry Energy carriers- ATP & NADPH carry

energy from light reaction to dark reactionenergy from light reaction to dark reaction Oxygen is producedOxygen is produced

REVIEW: LIGHT REVIEW: LIGHT REACTIONSREACTIONS

Reactants: HReactants: H220, sunlight energy0, sunlight energy

Products: OProducts: O22, ATP, NADPH, ATP, NADPH

6CO6CO22 + 6H + 6H220 + light = C0 + light = C66HH1212OO66 + 6O + 6O22

AN OVERVIEWAN OVERVIEW

BIOCHEMISTRY OF BIOCHEMISTRY OF PHOTOSYNTHESIS: DARK PHOTOSYNTHESIS: DARK REACTIONREACTION Dark reaction (Calvin Cycle)- in stromaDark reaction (Calvin Cycle)- in stroma ATP and NADPH can’t store all their energy ATP and NADPH can’t store all their energy

for a long time, so uses them to make high-for a long time, so uses them to make high-energy sugars energy sugars

1) CO1) CO22 molecules enter from atmosphere… molecules enter from atmosphere…

2) Energy from NADPH and ATP combine 2) Energy from NADPH and ATP combine with carbon (from COwith carbon (from CO22) and produce glucose ) and produce glucose

Review: Dark ReactionReview: Dark Reaction

Reactants: COReactants: CO22, ATP, NADPH, ATP, NADPH

Products: GlucoseProducts: Glucose

Photosynthesis DiagramPhotosynthesis Diagram

WorksheetWorksheet

Review: PhotosynthesisReview: Photosynthesis

Using your text, your notes, etc…Using your text, your notes, etc… Make a cartoon modeling the light and Make a cartoon modeling the light and

dark reactions of photosynthesisdark reactions of photosynthesis This cartoon should include graphics as This cartoon should include graphics as

well as textwell as text This should be for a student studying This should be for a student studying

photosynthesis in 8photosynthesis in 8thth grade. grade.