Two metabolic pathways

16 ADP + 16Pi

16 ATP

12 NADP + 12H

12 NADPH

12 H2O

24 H+ + 6O2

LIGHT DEPENDENT LIGHT INDEPENDENT

LIGHT DEPENDENT LIGHT INDEPENDENT

IN:

THYLAKOID STROMA

USES:

WATER, LIGHT CO2, ATP, NADPH

PRODUCES:

HIGH ENERGY COMPOUNDS GLUCOSE

LIGHT DEPENDENT REACTIONS

1. OCCURS

PHOTOSYSTEMS = EMBEDDED IN THYLAKOID MEMBRANE

2. CHLOROPHYLL

KEY LIGHT CAPTURING MOLECULE

ABSORBS LIGHT IN WAVELENGTHS OF RED, BLUE, VIOLET

3. ACCESSORY PIGMENTS

CAROTENOIDS AND PHYCOCYANINS

4. PHOTOSYSTEMS – TWO DIFFERENT ONES

a. Types

PHOTOSYSTEM I

PHOTOSYSTEM II

GENERAL ABOUT PHOTOSYSTEMS

1. THEY ARE EACH A LIGHT HARVESTING COMPLEX

2. GROUP OF MOLECULES (PROTEINS, CHLOROPHYLL, ACCESSORY

PIGMENTS, e- CARRIER MOLECULES) THAT WORK TOGETHER TO

HARVEST LIGHT INTO HIGH ENERGY COMPOUNDS

3. STRUCTURE - 2 PARTS

• LIGHT HARVESTING COMPLEX = 300 CHLOROPHYLL & ACCESSORY

• e- TRANSPORT CHAIN = SERIES OF e- CARRIER MOLECULES IN

MEMBRANE

Photosystem structure

Photosystem IPhotosystem II

Rxn Ctr P680

Rxn Ctr P700

ATP SYNTHASE

T

H

Y

L

A

K

O

I

D

M

E

M

B

Photosystem IPhotosystem II

Rxn Ctr P680

Rxn Ctr P700

ATP SYNTHASE

T

H

Y

L

A

K

O

I

D

M

E

M

B

Photosystem IPhotosystem II

Rxn Ctr P680

Rxn Ctr P700

ATP SYNTHASE

T

H

Y

L

A

K

O

I

D

M

E

M

B

2e-

2e-

Photosystem IPhotosystem II

Rxn Ctr P680

Rxn Ctr P700

ATP SYNTHASE

T

H

Y

L

A

K

O

I

D

M

E

M

B

2e-

2e-

H+ H+ H+ H+

H+ H+

H+ H+

OUTSIDE THYLAKOID

INSIDE THYLAKOID

Photosystem IPhotosystem II

ATP SYNTHASE

T

H

Y

L

A

K

O

I

D

M

E

M

B

2e-

2e-

H+ H+ H+ H+

H+ H+

H+ H+

12H2O

24H+ + 6O2

Photosystem IPhotosystem II

ATP SYNTHASE

T

H

Y

L

A

K

O

I

D

M

E

M

B

2e-

2e-

H+ H+ H+ H+

H+ H+

H+ H+

12H2O

24H+ + 6O2

16 ATP

16 ADP + P

Photosystem IPhotosystem II

ATP SYNTHASE

T

H

Y

L

A

K

O

I

D

M

E

M

B

2e-

2e-

H+ H+ H+ H+

H+ H+

H+ H+

12H2O

24H+ + 6O2

16 ATP

16 ADP + P

12 NADPH

12 NADP + 12 H