Govt Exams
Transpiration is highly dependent on atmospheric humidity. Lower humidity increases transpiration rate due to greater water vapor gradient.
Q10 of 2.0-3.0 indicates that enzyme activity doubles or triples with every 10°C increase in temperature, typical for biological systems.
In plants, anaerobic conditions lead to fermentation producing ethanol and CO2. Aerobic respiration yields ~30-32 ATP; Krebs cycle produces limited ATP directly; Glycolysis is cytoplasmic.
RuBisCO is the most abundant enzyme on Earth and catalyzes the carboxylation of RuBP with CO2 in the dark reactions.
The light compensation point for C3 plants typically occurs at 50-100 μmol/m²/s where photosynthesis equals respiration rate.
The correct electron flow is: PSII (P680) → Plastoquinone → Cytochrome b6f complex → Plastocyanin → PSI (P700) → NADP+ reductase.
Water photolysis (photosystem II) occurs in the thylakoid lumen where oxygen is released as a byproduct.
During drought, water loss causes cells to lose turgor pressure. ABA accumulation further reduces guard cell turgor by opening K+ efflux channels, closing stomata.
Carotenoids are accessory pigments that absorb light and protect against photoinhibition but do NOT participate directly in CO2 fixation.
In darkness, photosynthesis stops, but aerobic respiration continues, consuming O2 and releasing CO2, resulting in measurable gas exchange.