The absorption spectrum of a chromophore is only partly determined by its chemical structure. The environment also affects the observed spectrum, which mainly can

be described by three parameters:

protonation/deprotonation (pH, RedOx);

• solvent polarity (dielectric constant of the solvent); and

• orientation effects.

TLS Online TPP Program

#Id: 9221

#Unit 6. System Physiology – Plant

2-phosphoglycolate is an inhibitor of two chloroplast enzymes: triose phosphate isomerase and phosphofructokinase.

TLS Online TPP Program

#Id: 9222

#Unit 6. System Physiology – Plant

Warmer environments significantly limit the efficiency of photosynthetic carbon assimilation because the progressive increase in temperature tilts the balance away from photosynthesis (carboxylation) and toward photorespiration (oxygenation)

TLS Online TPP Program

#Id: 9223

#Unit 6. System Physiology – Plant

Warmer environments have the effect of: Increasing the oxygenase activity of rubisco more than the carboxylase activity.

TLS Online TPP Program

#Id: 9224

#Unit 6. System Physiology – Plant

Warmer environments have the effect of: Lowering the solubility of CO2 to a greater extent than O2

TLS Online TPP Program

#Id: 9225

#Unit 6. System Physiology – Plant

Warmer environments have the effect of: Reducing the stomatal aperture to conserve water. The stomatal closure lowers the uptake of atmospheric CO2, thereby decreasing CO2 at the active site of rubisco.

TLS Online TPP Program

#Id: 9226

#Unit 6. System Physiology – Plant

Carbon cycle, nitrogen cycle, and oxygen cycle atoms circulate through photorespiration