Photosynthesis: Role of Carbon Dioxide

Carbon Dioxide in Photosynthesis

Role of CO2 in Photosynthesis

• Carbon dioxide is one of the essential reactants in photosynthesis
• It provides the carbon atoms necessary for the synthesis of glucose and other organic compounds

Light-Independent Reactions

• CO2 is fixed into a three-carbon molecule called 3-phosphoglycerate (3-PGA) via the enzyme RuBisCO
• This process is known as the Calvin cycle
• CO2 is reduced to form glucose using the energy from ATP and NADPH produced in the light-dependent reactions

Importance of CO2 Concentration

• CO2 concentration affects the rate of photosynthesis
• Higher CO2 concentrations can increase the rate of photosynthesis, up to a certain point
• This is because CO2 is a limiting factor in photosynthesis, and increasing its concentration can overcome this limitation

Factors Affecting CO2 Uptake

• CO2 uptake is affected by factors such as:
  • Temperature: optimal temperature for CO2 uptake varies among plants
  • Water availability: drought can limit CO2 uptake
  • Light intensity: high light intensity can increase CO2 uptake

Agricultural Implications

• Increasing CO2 concentrations in greenhouses can increase crop yields
• This is because CO2 is a limiting factor in photosynthesis, and increasing its concentration can overcome this limitation

Carbon Dioxide in Photosynthesis

Role of CO2

• Essential reactant in photosynthesis, providing carbon atoms for glucose and other organic compounds synthesis

Calvin Cycle

• CO2 is fixed into 3-phosphoglycerate (3-PGA) via RuBisCO enzyme
• CO2 is reduced to form glucose using ATP and NADPH energy from light-dependent reactions

CO2 Concentration Effects

• Affects photosynthesis rate, with higher concentrations increasing rate up to a point
• CO2 is a limiting factor in photosynthesis, and increasing its concentration can overcome this limitation

Factors Affecting CO2 Uptake

• Temperature: optimal temperature for CO2 uptake varies among plants
• Water availability: drought limits CO2 uptake
• Light intensity: high light intensity increases CO2 uptake

Agricultural Implications

• Increasing CO2 concentrations in greenhouses increases crop yields
• Overcomes CO2 limitation in photosynthesis, increasing crop production