FACTORS

• MAIN LIMITING FACTORS AFFECTING PHOTOSYNTHESIS RATE?

  • light intensity
  • CO2 concentration
  • temperature
• CORRELATION BETWEEN LIGHT INTENSITY AND PHOTOSYNTHESIS RATE?

  positive
• HOW DOES INCREASING LIGHT INTENSITY INCREASE PHOTOSYNTHESIS RATE?

  • more energy for LDR
  • happens faster
  • more ATP and NADPH produced
  • LIR happens faster
• LIGHT INTENSITY GRAPH?

  increases then plateaus
• CORRELATION OF CO2 CONCENTRATION AND PHOTOSYNTHESIS?

  positive
• HOW DOES CO2 CONCENTRATION AFFECT PHOTOSYNTHESIS RATE?

  • required for LDR
  • more reacts with RuBP
  • faster
• CO2 CONCENTRATION GRAPH?

  increases then plateaus
• TEMPERATURE GRAPH?

  increases, peaks, decreases
• HOW DOES TEMPERATURE AFFECT RATE OF PHOTOSYNTHESIS?

  • increases to a point
  • as LIR controlled by enzymes
  • decreases after a certain point
  • as enzymes denatured
• HOW CAN FARMERS PROVIDE THE OPTIMUM ENVIRONMENT FOR PHOTOSYNTHESIS?

  • sensors
  • factors managed and adjusted by a computer
  • irrigation systems (+ additional fertilisers/ growth nutrients)
  • pesticides
• WHAT DO AGRICULTURAL PRACTICES HELP DO?

  maximise yield while keeping a low cost
• OTHER (NON-LIMITING) FACTORS AFFECTING PHOTOSYNTHESIS RATE?

  • water availability
  • number of chloroplasts
  • RuBP
• EXPLAIN THE CO2 CONCENTRATION GRAPH?

  • as carbon dioxide concentration increases
  • photosynthesis rate increases
  • as more CO2 joins with RuBP
  • more Calvin Cycle occurs
  • CO2 is the limiting factor
  • graph then plateaus as CO2 no longer the limiting factor
  • temperature/ light intensity new limiting factor
• EXPLAIN THE LIGHT INTENSITY GRAPH?

  • increased light intensity
  • increases photosynthesis rate
  • increase light dependent reaction due to increased photolysis and phosphorylation
  • therefore light intensity is the limiting factor
  • graph then plateaus as light intensity is no longer the limiting factor
  • CO2 concentration/ temperature is the new limiting factor
• EXPLAIN THE GRAPH OF TEMPERATURE?

  • at a low temperature, enzymes have low KE
  • so fewer enzyme-substrate complexes are formed
  • however as temperature increases, rate increases
  • as temperature is closer to optimum (maximum rate of photosynthesis)
  • temperature is the limiting factor
  • at high temperatures, hydrogen bonds in tertiary protein break
  • active site changes shape
  • enzymes begin to denature
  • fewer enzyme-substrate complexes