Light Heat Reflection Absorption Fluorescence Reflection Heat Absorption

Light

Heat Reflection Absorption

Fluorescence Reflection Heat Absorption

Fluorescence Reflection Heat Sugar Absorption CO 2 2 H 2 O O 2 + 4 H+

Pulse Amplitude Modulated Fluorometry

PAM Fluorometry • Measures photosynthesis using only light • Follow real-time changes in photosynthesis • Quantify stress effects (i. e. UVR, salinity, light intensity, temperature, desicca • Non-invasive • No moving parts • Easily adaptable for space flight

PAM Fluorometry

PAM Fluorometry (FM-FT)/FM = Quantum Yield

PAM Fluorometry Chlorophyll content Number and function of PSII Light intensity [NADP+] (FM-FT)/FM = Quantum Yield Xanthophyll cycle - algae State transitions - cyanos

PAM Fluorometry 0. 65 UVR PSII Efficiency 0. 6 0. 55 0. 45 0. 4 0. 35 0. 3 0 10 20 30 40 Minutes 50 60 70 80

PAM Fluorometry • Measures photosynthesis using only light Weeks • Follow real-time changes in photosynthesis • Quantify stress effects (i. e. UVR, salinity, light intensity, temperature, desicca • Non-invasive • No moving parts • Easily adaptable for space flight

Algae. Sat – A nanosatellite with PAM Environmental Control -Nutrient Flow, Light intensity, Temperature

Gravi. Sat – Another nanosat with PAM Environmental Control -Nutrient Flow, Light intensity, Temperature, artificial grav 0. 9 0. 8 0. 7 0. 6 0. 5 0. 4 0. 3 0. 2 0. 1 0 2/16/2011 3/8/2011 3/28/20114/17/2011 5/27/20116/16/2011

PAM Fluorometry Definitions Variable Fluorescence = FM – FT FM= Maximum fluorescence Quantum Yield (Y) or Photosynthetic Efficiency = (FM-FT)/FM Electron transport rate (ETR) = Y*Light intensity*Conversion constant Maximum Quantum Yield – Dark adapted yield, PSII capacity Photochemical Quenching – Percent of PSII centers that are Carbon fixation Sugar production open Cell growth Non-Photochemical Quenching – Any process other than photochemistry that lowers the variable fluorescence