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Chapter Opener 7-1

© 2014 Pearson Education, Inc.

Figure 7-1 An overview of photosynthetic structures

Leaves

cuticleupperepidermis

lowerepidermis

mesophyllcells

chloroplasts

outer membraneinner membranethylakoidstroma

stoma

stomabundle sheath cells

vascular bundle (vein)

channelinterconnectingthylakoids

Internal leaf structure

Mesophyll cell containing chloroplasts

Chloroplast

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Figure 7-1a Leaves

Leaves

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Figure 7-1b Internal leaf structure

cuticleupperepidermis

lowerepidermis

mesophyllcells

chloroplasts

stoma

bundle sheath cellsvascular bundle (vein)

stoma

Internal leaf structure

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Figure 7-1c Mesophyll cell containing chloroplasts

Mesophyll cell containingchloroplasts

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Figure 7-1d Chloroplast

outer membraneinner membranethylakoidstroma

channelinterconnectingthylakoidsChloroplast

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Figure 7-2 Stomata

Stomata open Stomata closed

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Figure 7-2a Stomata open

Stomata open

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Figure 7-2b Stomata closed

Stomata closed

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Figure 7-3 An overview of the relationship between the light reactions and the Calvin cycle

energy fromsunlight

chloroplast

thylakoid

lightreactions

Calvincycle

sugar

C6H12O6O2

CO2H2O 66

(stroma)

ATP

NADPH

ADP

NADP

© 2014 Pearson Education, Inc.

Figure 7-4 Light and chloroplast pigments

lig

ht

abso

rpti

on

(p

erce

nt)

chlorophyll b

chlorophyll a

carotenoids

wavelength (nanometers)

visible light

higher energy lower energy

gamma rays X-rays UV infraredmicro-waves

radiowaves

100

80

60

40

20

0

400 500450 550 650 750700600

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Figure 7-6 Energy transfer and the light reactions of photosynthesisH2O CO2

ATP

ADP

NADPH

NADP

lightreactions

Calvincycle

sugar

high

O2 C6H12O6

primaryelectronacceptor

lightenergy

e

e

en

erg

y le

ve

l o

f e

lect

ron

s

pigmentmolecules

electrontransportchain II

e

e

reaction centerchlorophyll a molecules

ATP

Photosystem II

H

O2

2H2O

low

e

ee

NADP H

NADPH

electrontransportchain I

Photosystem I

½

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Slide 1

H2O

lightreactions

O2

ATP

NADPH

ADP

NADP+

CO2

Calvincycle

sugar

C6H12O6high

primaryelectronacceptor

e–

e–

en

erg

y le

ve

l o

f e

lect

ron

s

low

lightenergy

e–

electrontransportchain II

pigmentmolecules

e–

ATP

reaction centerchlorophyll a molecules

Photosystem II

Photosystem I

e–

e–

electrontransportchain I

e–

NADP+

NADPH

H+

H2OH+2

O221

Figure 7-6 Energy transfer and the light reactions of photosynthesis

© 2014 Pearson Education, Inc.

Slide 2

H2O

lightreactions

O2

ATP

NADPH

ADP

NADP+

CO2

Calvincycle

sugar

C6H12O6

Figure 7-6 Energy transfer and the light reactions of photosynthesis

© 2014 Pearson Education, Inc.

Slide 3

H2O

lightreactions

O2

ATP

NADPH

ADP

NADP+

CO2

Calvincycle

sugar

C6H12O6high

primaryelectronacceptor

e–

en

erg

y le

ve

l o

f e

lect

ron

s

low

lightenergy

pigmentmolecules

e–

reaction centerchlorophyll a molecules

Photosystem II

H2OH+2

O221

Figure 7-6 Energy transfer and the light reactions of photosynthesis

© 2014 Pearson Education, Inc.

Slide 4

H2O

lightreactions

O2

ATP

NADPH

ADP

NADP+

CO2

Calvincycle

sugar

C6H12O6high

primaryelectronacceptor

e–

e–

en

erg

y le

ve

l o

f e

lect

ron

s

low

lightenergy

e–

electrontransportchain II

pigmentmolecules

e–

ATP

reaction centerchlorophyll a molecules

Photosystem II

Photosystem I

H2OH+2

O221

Figure 7-6 Energy transfer and the light reactions of photosynthesis

© 2014 Pearson Education, Inc.

Slide 5

H2O

lightreactions

O2

ATP

NADPH

ADP

NADP+

CO2

Calvincycle

sugar

C6H12O6high

primaryelectronacceptor

e–

e–

en

erg

y le

ve

l o

f e

lect

ron

s

low

lightenergy

e–

electrontransportchain II

pigmentmolecules

e–

ATP

reaction centerchlorophyll a molecules

Photosystem II

Photosystem I

e–

e–

electrontransportchain I

e–

NADP+

NADPH

H+

H2OH+2

O221

Figure 7-6 Energy transfer and the light reactions of photosynthesis

© 2014 Pearson Education, Inc.

Figure 7-7 Events of the light reactions occur in and near the thylakoid membranethylakoid

chloroplast

lightenergy H is pumped into

the thylakoid spaceH

electron transport chain II

e

e

e

e

e

H

H H

H

H

photosystem II

2

H2O O2

A high H concentration iscreated in the thylakoid space(thylakoid space)

(stroma)

electrontransportchain I NADP

NADPH

ATPsynthase

ADP

e

photosystem I

H

H

HH

thylakoidmembrane

The flow of H downits concentration gradientpowers ATP synthesis

HPi

ATP

sugar

Calvincycle

C6H12O6

CO2

½

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Slide 4

H+

thylakoid

chloroplast

lightenergy

e–

e–

e–

e–

e–e–

H+ is pumped intothe thylakoid space

electron transport chain II

photosystem II

photosystem I

H+

electrontransportchain I

(stroma)

NADP+

NADPH

ATPsynthase

CO2

sugar

Calvincycle

C6H12O6

ATPH+

ADP

Pi

H+

H+

H+H+

thylakoidmembrane

The flow of H+ downits concentration gradientpowers ATP synthesis

A high H+ concentration iscreated in the thylakoid space

H+

H+H+

H+2

H2O O221

(thylakoid space)

Figure 7-7 Events of the light reactions occur in and near the thylakoid membrane

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Figure 7-8 A dam allows a “water gradient” to be used to generate electricity

Energy is releasedas water flows downhill

Energy is harnessedto rotate a turbine

The energy of therotating turbine is usedto generate electricity

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Figure 7-9 The Calvin cycle fixes carbon from CO2 and produces the simple sugar G3P

H2O CO2

ATP

NADPH

ADP

NADP

Calvincyclelight

reactions

sugar

O2 C6H12O6

CO2

3 Carbon fixation combines three CO2

with three RuBP usingthe enzyme rubisco

3 6

RuBP PGA

Calvincycle

6

6

6

6

6

G3P

ATP

ADP

NADPH

NADP

G3P

ADP

ATP3

3

5

G3P

G3P G3P glucose

1

1 1 1

Using the energyfrom ATP, the fiveremaining moleculesof G3P are convertedto three moleculesof RuBP

Energy from ATPand NADPH is usedto convert the sixmolecules of PGA tosix molecules of G3P

One molecule ofG3P leaves the cycle

Two molecules of G3P combineto form glucose and other molecules

© 2014 Pearson Education, Inc.

lightreactions

Calvincycle

sugar

CO2

C6H12O6

H2O

O2

ATP

NADPH

ADP

NADP+

CO2

3 Carbon fixationcombines three CO2

with three RuBP usingthe enzyme rubisco

3

3

3

ADP

ATP

RuBP

6

PGA

Energy from ATPand NADPH is usedto convert the sixmolecules of PGA tosix molecules of G3P

6

6

6

6

65

G3PG3P

G3P

1

ATP

ADP

NADPH

NADP+

Calvincycle

Using the energyfrom ATP, the fiveremaining moleculesof G3P are convertedto three moleculesof RuBP

1 1

G3P G3P

1

glucose

One molecule ofG3P leaves the cycle

Two molecules of G3P combineto form glucose and other molecules

Slide 1Figure 7-9 The Calvin cycle fixes carbon from CO2 and produces the simple sugar G3P

© 2014 Pearson Education, Inc.

lightreactions

Calvincycle

sugar

CO2

C6H12O6

H2O

O2

ATP

NADPH

ADP

NADP+

CO2

3 Carbon fixationcombines three CO2

with three RuBP usingthe enzyme rubisco

Slide 2Figure 7-9 The Calvin cycle fixes carbon from CO2 and produces the simple sugar G3P

© 2014 Pearson Education, Inc.

lightreactions

Calvincycle

sugar

CO2

C6H12O6

H2O

O2

ATP

NADPH

ADP

NADP+

CO2

3 Carbon fixationcombines three CO2

with three RuBP usingthe enzyme rubisco

6

PGA

Energy from ATPand NADPH is usedto convert the sixmolecules of PGA tosix molecules of G3P

6

6

6

6

6

G3P

ATP

ADP

NADPH

NADP+

Calvincycle

Slide 3Figure 7-9 The Calvin cycle fixes carbon from CO2 and produces the simple sugar G3P

© 2014 Pearson Education, Inc.

lightreactions

Calvincycle

sugar

CO2

C6H12O6

H2O

O2

ATP

NADPH

ADP

NADP+

CO2

3 Carbon fixationcombines three CO2

with three RuBP usingthe enzyme rubisco

3

3

3

ADP

ATP

RuBP

6

PGA

Energy from ATPand NADPH is usedto convert the sixmolecules of PGA tosix molecules of G3P

6

6

6

6

65

G3PG3P

ATP

ADP

NADPH

NADP+

Calvincycle

Using the energyfrom ATP, the fiveremaining moleculesof G3P are convertedto three moleculesof RuBP

Slide 4Figure 7-9 The Calvin cycle fixes carbon from CO2 and produces the simple sugar G3P

© 2014 Pearson Education, Inc.

lightreactions

Calvincycle

sugar

CO2

C6H12O6

H2O

O2

ATP

NADPH

ADP

NADP+

CO2

3 Carbon fixationcombines three CO2

with three RuBP usingthe enzyme rubisco

3

3

3

ADP

ATP

RuBP

6

PGA

Energy from ATPand NADPH is usedto convert the sixmolecules of PGA tosix molecules of G3P

6

6

6

6

65

G3PG3P

G3P

1

ATP

ADP

NADPH

NADP+

Calvincycle

Using the energyfrom ATP, the fiveremaining moleculesof G3P are convertedto three moleculesof RuBP

1 1

G3P G3P

1

glucose

One molecule ofG3P leaves the cycle

Two molecules of G3P combineto form glucose and other molecules

Slide 5Figure 7-9 The Calvin cycle fixes carbon from CO2 and produces the simple sugar G3P

© 2014 Pearson Education, Inc.

Figure E7-1 The C4 pathway and the CAM pathway

CO2

mesophyllcellPEP

(3C)PEPcarboxylase

pyruvate(3C)oxaloacetate

(4C)

malate(4C)

malate(4C)

pyruvate(3C)

rubisco

Calvincycle

CO2

bundlesheathcell

sugar

C4 plants CAM plants

malate(4C) malate

(4C)

Calvincycle

sugar

malic acid(4C)

central vacuole

rubisco

PEP(3C)

PEPcarboxylase

pyruvate(3C)

oxalo-acetate

(4C)

CO2

mesophyllcell

daynight

CO2

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Figure E7-1a C4 plantsCO2

mesophyllcellPEP

(3C)PEPcarboxylase

pyruvate(3C)oxaloacetate

(4C)

malate(4C)

malate(4C)

pyruvate(3C)

rubisco

Calvincycle

CO2

bundlesheathcell

sugar

C4 plants

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Figure E7-1b CAM plants

CAM plants

malate(4C)

malate(4C)

Calvincycle

sugar

malic acid(4C)

central vacuole

rubisco

PEP(3C)

PEPcarboxylase

pyruvate(3C)

oxalo-acetate

(4C)

CO2

mesophyllcell

daynight

CO2