Lec7FactorsAffectingPhotosynthesis

Portable photosynthesis meter measured gases entering

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Unformatted text preview: opy Architecture Factors Affecting Photosynthesis How is photosynthesis measured? • Portable photosynthesis meter • Measured gases entering and gases exiting chamber • Units – CO2 • Uptake • Fixation • Assimilation gas exchange meter puts air into the chamber and out of the chamber the difference is amount it used. It measures net photosynthesis Factors Affecting Photosynthesis Net photosynthesis it is - 0.5V0 bc it releases CO2 where it suppose to use it. An = Vc – 0.5Vo - R • • • • An = net photosynthetic (assimilation) rate ( mol m-2 s-1) Vc = carboxylation rate of RUBISCO Vo = oxygenation rate of RUBISCO (photorespiration) R = respiration rate (i.e. leaf mitochondria, or roots etc) using sugar to release CO2 for every 4 reaction that rubisco one of them is photorespiration in the dark Rubisco is not working cause no photon, so during night the net rate of carbon dioxide exchange is negative because we are only having Respiration rate happening through the mitochond Factors Affecting Photosynthesis Text Light 660-450 • Light Quality (Color) – Chlorophyll absorbs light between red (660 nm) and blue (450 nm) wavelengths – These are the photosynthetic wavelengths of light • Called Photosynthetically Active Radiation (PAR) Factors Affecting Photosynthesis as you add more light, it saturates bc not enough enzyme • Intensity – Saturation point – Compensation point Txt • In low light, respiration may exceed photosynthesis – Photoin...
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This document was uploaded on 01/17/2014.

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