Photosynthesis and Carbon Fixation Mechanisms

Flashcards designed to review key terms and concepts related to photosynthesis, carbon fixation mechanisms, and various adaptations in plants.

Photorespiration

A wasteful side reaction catalyzed by RuBisCO that consumes O2 and produces CO2, occurring under hot and dry conditions.

RuBisCO

An enzyme that facilitates the carboxylation and oxygenation reactions of RuBP, key to photosynthesis but also involved in photorespiration.

C3 Pathway

Nature's only net carbon fixation pathway that uses RuBisCO for the fixation of CO2.

C4 Photosynthesis

A photosynthetic pathway that fixes CO2 into a 4-C compound to minimize photorespiration, by spatially separating the Calvin cycle from initial CO2 fixation.

CAM Photosynthesis

A carbon fixation pathway where CO2 is fixed at night and then used during the day, effectively separating CO2 accumulation from its utilization temporally.

PEP Carboxylase

An enzyme with high affinity for CO2 that catalyzes the first step of the C4 pathway, allowing efficient fixation in low CO2 conditions.

Bundle Sheath Cells

Cells in C4 plants that contain RuBisCO and carry out the Calvin cycle, where CO2 is reassimilated into organic material.

Photorespiratory Pathway

The process through which 2-P-Glycolate is salvaged after being produced during photorespiration, involving chloroplasts, peroxisomes, and mitochondria.

Water Use Efficiency (WUE)

The unit of dry matter produced per unit of water used, higher in C4 plants compared to C3 plants.

Photosynthesis Timeline

A chronological account detailing key discoveries and developments in understanding photosynthesis from ancient times to modern research.