Introduction
Carbon Fixation
C3 carbon fixation is one of three metabolic pathways for carbon fixation in photosynthesis, along with C4 and CAM. This process converts carbon dioxide and ribulose bisphosphate into 3-phosphoglycerate.
C4 carbon fixation is one of three biochemical mechanisms. It is named for the 4-carbon molecule present in the first product of carbon fixation in the small subset of plants known as C4 plants.
Task
C3 Photosynthesis
C4 Photosynthesis
Process
Plant Species Include:
C3 Plants C4 Plants
- Rice - Sorghum
- Barley - Sugar cane
- Juniper - Maize
- Baobab - Papyrus
- Maple tree - Switchgrass
- Raspberry plant - Prairie Bluestems
- Venus Flytrap - Black Grana
- Poppy - Millet
- Blueberry - Amaranths
- Banana Tree - Certain Cacti species
Evaluation
Growth Conditions
C3 plants tend to thrive in areas where sunlight intensity is moderate, temperatures are moderate, carbon dioxide concentrations are around 200 ppm and ground water is plentiful.
C4 Plants are more efficient where temperatures are higher and light intensity greater.
Conclusion
C4 plants have a competitive advantage over plants possessing the more common C3 carbon fixation pathway under conditions of drought, high temperatures and CO2 limitation. When grown in the same environment, at 30 °C, C3 grasses lose approximately more water per CO2 molecule that is fixed than C4 grasses. This increased water use efficiency of C4 grasses means that soil moisture is conserved, allowing them to grow for longer in arid environments.