This document describes two metabolic pathways in photosynthesis - the light dependent and light independent reactions. The light dependent reactions use water, light, chlorophyll and accessory pigments in the thylakoid membrane to produce ATP, NADPH, and oxygen through the absorption of light by photosystems. The light independent reactions then use ATP, NADPH, and carbon dioxide in the stroma to produce glucose and other high energy compounds.

1. Two metabolic pathways
LIGHT DEPENDENT LIGHT INDEPENDENT
16 ADP + 16Pi
16 ATP
12 NADP + 12H
12 NADPH
12 H2O
24 H+ + 6O2

2. LIGHT DEPENDENT LIGHT INDEPENDENT
IN:
THYLAKOID STROMA
USES:
WATER, LIGHT CO2, ATP, NADPH
PRODUCES:
HIGH ENERGY COMPOUNDS GLUCOSE

3. 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

4. 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

5. Photosystem structure
ATP SYNTHASE
T
H
Y
L
A
K
O
I
D Rxn Ctr P700
M Rxn Ctr P680
E
M
B
Photosystem II Photosystem I

6. ATP SYNTHASE
T
H
Y
L
A
K
O
I
D Rxn Ctr P700
M Rxn Ctr P680
E
M
B
Photosystem II Photosystem I

7. ATP SYNTHASE
T
H
Y
L
A 2e-
K 2e-
O
I
D Rxn Ctr P700
M Rxn Ctr P680
E
M
B
Photosystem II Photosystem I

8. H+ H+ H+ H+
OUTSIDE THYLAKOID
H+ H+
H+ H+
ATP SYNTHASE
T
H
Y
L
A 2e-
K 2e-
O
I
D Rxn Ctr P700
M Rxn Ctr P680
E
M
B
Photosystem II Photosystem I
INSIDE THYLAKOID

9. H+ H+ H+ H+
H+ H+
H+ H+
ATP SYNTHASE
T
H
Y
L
A 2e-
K 2e-
O
I
D
M
E
12H2O
M
B
24H+ + 6O2 Photosystem II Photosystem I

10. H+ H+ H+ H+
16 ATP
H+ H+
H+ H+ 16 ADP + P
ATP SYNTHASE
T
H
Y
L
A 2e-
K 2e-
O
I
D
M
E 12H2O
M
B
24H+ + 6O2 Photosystem II Photosystem I

11. H+ H+ H+ H+
16 ATP
H+ H+ 12 NADPH
12 NADP + 12 H
H+ H+ 16 ADP + P
ATP SYNTHASE
T
H
Y
L
A 2e-
K 2e-
O
I
D
M
E 12H2O
M
B
24H+ + 6O2 Photosystem II Photosystem I