The simplest method to measure population density is to visually count the number of organisms in a population in a given habitat.

TLS Online TPP Program

#Id: 7281

#Unit 6. System Physiology – Plant

Glyceraldehyde- 3-phosphate dehydrogenase and phosphoribulokinase is regulated by CP12 by forming supramolecular complex.

TLS Online TPP Program

#Id: 7282

#Unit 6. System Physiology – Plant

All the reactions of the Calvin cycle except those catalyzed by rubisco, sedoheptulose 1,7-bisphosphatase, and ribulose 5-phosphate kinase also take place in animal tissues. Lacking these three enzymes, animals cannot carry out net conversion of CO2 to glucose.

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#Id: 7283

#Unit 6. System Physiology – Plant

An important property of rubisco is its ability to catalyze both the carboxylation and the oxygenation of RuBP. Oxygenation is the primary reaction in a process known as photorespiration

TLS Online TPP Program

#Id: 7284

#Unit 6. System Physiology – Plant

C2 oxidative photosynthetic carbon cycle requires the participation of three organelles—chloroplasts, mitochondria, and peroxisomes

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#Id: 7285

#Unit 6. System Physiology – Plant

Evolution of oxygenase activity occurred before the time, about 2.5 billion years ago, when production of O2 by photosynthetic organisms started to raise the oxygen content of the atmosphere.

TLS Online TPP Program

#Id: 7286

#Unit 6. System Physiology – Plant

That time, there was no selective pressure for rubisco to discriminate between CO2 and O2. 

The Km for CO2 is about 9 microM, and that for O2 is about 350 microM. The modern atmosphere contains about 20% O2 and only 0.04% CO2, so an aqueous solution in equilibrium with air at room temperature contains about 250 microM O2 and 11 microM CO2—concentrations that allow significant O2 “fixation” by rubisco and thus a significant waste of energy.