Omega loop

TLS Online TPP Program

#Id: 9227

#Unit 6. System Physiology – Plant

The specificity factor (W) estimates the preference of rubisco for CO2 versus O2

where Vc and Vo  are the maximum velocities for carboxylation and oxygenation, respectively, and Kc and Ko are the Michaelis–Menten constants for CO2 and O2, respectively

TLS Online TPP Program

#Id: 9228

#Unit 6. System Physiology – Plant

8 μM CO2 (0.038%) and 250 μM O2 (21%) at 25°C. Therefore, a specificity factor of 100 gives a Vc/Vo ratio of 3.2.

TLS Online TPP Program

#Id: 9229

#Unit 6. System Physiology – Plant

C2 oxidative photosynthetic carbon cycle is essential for land plants for retrieving the carbon atoms of 2-phosphoglycolate.

TLS Online TPP Program

#Id: 9230

#Unit 6. System Physiology – Plant

C4 and CAM plants have evolved to limit photorespiration by concentrating CO2 at the site of carbon fixation.

The deleterious impact of photorespiration evolved C4 and CAM plants

TLS Online TPP Program

#Id: 9231

#Unit 6. System Physiology – Plant

TLS Online TPP Program

#Id: 9232

#Unit 6. System Physiology – Plant

In photosynthesis, the relationship of O2 evolved to CO2 taken up is 1:1. 

In photorespiration, 3 O2 are taken up for every CO2 evolved.