Terminology Related to Metabolism
C2.1: Use appropriate terminology related to metabolism (Photosynthesis steps).
Laboratory Investigation
C2.3: Conduct a laboratory investigation into photosynthesis to identify products and display them appropriately.
Chemical Changes and Energy Conversions
C3.2: Explain chemical changes and energy conversions during photosynthesis.
Matter and Energy Transformations
C3.4: Describe and illustrate matter and energy transformations, including roles of oxygen and chloroplasts.
Photosynthesis is crucial for the sustainable management of Canada's boreal forest, impacting both ecology and economy.
This process allows trees and plants to convert about 12.5 million tonnes of carbon dioxide into organic compounds annually.
Metabolic pathways within cells convert high-energy compounds (like glucose) into usable energy (ATP).
Chlorophyll absorbs light energy and synthesizes carbohydrates from CO2 and water.
Materials Needed:
Beaker of chlorophyll solution, light source.
Procedure:
Shine a strong light on chlorophyll solution in a dark room.
Observe chlorophyll color at different angles and analyze fluorescence.
Key Terms:
Light-dependent reaction, light-independent reaction, thylakoid, pigment, photosystem, photophosphorylation.
Photosynthesis transforms sunlight into chemical energy.
Only 1-2% of sunlight reaching Earth is used by photosynthesizing organisms (e.g., cyanobacteria, plants).
Photosynthesis produces 1.4 x 10^15 kg of energy-storing compounds like glucose each year.
Structural components (cellulose) and metabolic substances (sugars, amino acids) are made from glucose.
General Equation for Photosynthesis:
6CO2 + 6H2O + energy → C6H12O6 + 6O2
Photosystems: Two types present: PS I (P700) and PS II (P680).
Photosystem II absorbs light, creating an energized electron and splitting water, releasing oxygen.
Pigments: Chlorophyll a and b absorb red and blue light but reflect green, giving leaves their color.
Chloroplasts contain thylakoids, granum, and stroma, essential for photosynthesis.
CO2 enters through stomata, while water is absorbed through the roots, entering the thylakoids.
Pigments, embedded in thylakoid membranes, absorb light energy crucial for energy synthesis.
The antenna complex gathers light and transfers energy to the reaction center.
Noncyclic photophosphorylation: Photon energies from PS II and I create NADPH and ATP for Calvin cycle.
Cyclic photophosphorylation: Provides additional ATP without producing NADPH or oxygen.
Carbon fixation occurs in the stroma, turning CO2 into G3P, the foundational block for glucose.
Enzyme: ribulose bisphosphate carboxylase (RuBisCO) catalyzes initial reactions.
Phases of Calvin Cycle:
Carbon dioxide fixation.
Reduction phase - G3P formation.
Regeneration of RuBP.
C3 Plants: Struggle with photorespiration; can utilize CO2 efficiently under optimal conditions.
C4 Plants: Separate initial CO2 fixation and the Calvin cycle reactions to enhance efficiency in hot climates.
CAM Plants: Fix CO2 at night, store it for daytime use, minimizing water loss.
Understanding photosynthesis has implications for agriculture, bioengineering, and combating climate change.
Current research focuses on improving efficiency and mimicking photosynthetic processes for sustainable energy solutions.