Photosynthesis Equation and Components

Importance of Balanced Equation

• The balanced equation shows the correct ratio of reactants to products in photosynthesis.
• The equation is: 6CO2 + 6H2O + light energy → C6H12O6 (glucose) + 6O2

Components and Materials Required

• Carbon Dioxide (CO2)
• Water (H2O)
• Sunlight (energy)
• Chlorophyll (necessary for photosynthesis, but not directly consumed)

Physical Locations of Reactions

• Light Dependent Reaction: Takes place in the Thylakoids (stacked, coin-like structures inside the chloroplast)
• Calvin Cycle (Light Independent Reaction): Takes place in the Stroma (liquid filling inside the chloroplast)

Light Dependent Phase

• Photolysis: Water molecule is divided into Hydrogen and Oxygen using light energy
• Hydrogen is a crucial component for glucose production
• Oxygen is released as a byproduct in the form of gas

Photo Excitation

• Creates NADPH from NADP+
• Hydrogen is pumped from the stroma into the thylakoid space
• Hydrogen is pumped out of the thylakoid space through ATP synthase, converting ADP to ATP
• Electrons transfer from photosystem 2 to photosystem 1 to the electron transport chain

Electron and Hydrogen Ion

• High-energy electrons produce ATP (energy carrier)
• Hydrogen ions are attached to a hydrogen acceptor (NADP) to form NADPH
• Hydrogen ions are pumped into the thylakoid space

Calvin Cycle (Light Independent Phase)

• Key components: Ribose Biphosphate (RuBP), Carbon Dioxide, and Rubisco (enzyme)
• RuBP combines with CO2 through Rubisco to form a 6-carbon compound (unstable)
• The 6-carbon compound breaks down into two identical PGA molecules (3 carbons each)
• PGA molecules are modified using NADPH and ATP from the light dependent phase to produce glucose

ATP and NADPH Molecules

• ATP delivers energy to fuse molecules together, making them more stable
• NADPH delivers hydrogen, resulting in a substance called PGA

PGA Molecule

• Has three carbons and can become glucose
• Requires multiple cycles to form glucose, combining two PGA molecules

Reformation of RuBP

• Some PGA molecules are used to reform the five-carbon RuBP molecule
• This process is not fully explained in this simplified example

End of Light Independent Phase

• Glucose is produced and stored as sugars and starches
• ATP and NADPH molecules are recycled back to the light dependent phase