How Many Plants Would it Take to Keep You Alive?

CO2 Diffusion in a Leaf

6NADP+

6NADPH

H+

6H2O 3 O2

12H+

12H+

12H+

ADP

ATP

H+

Photosynthetic Electron TransportThe “Light” Reactions

Stroma

Lumen

12e-

12e-PSII

Cyt b6f

PSI ATPase

GAPDH

6 PGA (3C)

rubisco

3 RuBP (5C)3 CO2 (1C)

6 1,3 BisPGA (3C)

GAP GAP GAP GAP (3C)GAP GAP

DHAP (3C)

F1,6BP (6C)

F6P (6C)

X5P (5C) E4P (4C)

Ru5P (5C)

DHAP (3C)

S1,7BP (7C)

S7P (7C)

X5P (5C) R5P (4C)

Ru5P (5C) Ru5P (5C)

Sucrose, Starch,other Fun Stuff

6 NADPH6 NADP

6 ATP6 ADP

6 ATP6 ADP

Stroma

PGA Kinase

FBPaseSBPase

PRK

Caboxylation

Reduction

Regeneration

Photosynthesis, Our Life Support System!

Light Reactions

Splits H2OO2 ProductionNADPH and ATP

H+

4H+

NADPH

H2O O24H+

4H+

ATP

8H+

atmosphere

The Greenhouse Effect

air

flow

Infrared lightdetector

Infrared lightSource

Put To Good Use !

Measuring Water Vapor

• Relative Humidity (%)

• Partial Pressure (kPa)

• Mole Fraction (ppt)

• Dew Point (°C)

Measuring Irradiance

Photometric Sensor Quantum Sensor

Units: Lux or Footcandles Units: µmol m-2 s-1 or µE m-2s-1

PAR = Photosynthetically Active Radiation 400 – 700 nm

PPFD = Photosynthetic Photon Flux Density, also called Quantum Flux

Conditions to Measure Photosynthesis At

• What Factors Could influence the Photosynthetic rate of the plant?

• What conditions are the most realistic for how our life support plants will be growing and photosynthesizing

LI-COR 6400