4.1.2 Factors Affecting Photosynthesis

• Very high light intensity can damage the photosynthetic apparatus


  True
• Water is a reactant necessary for photosynthesis

  True
• Very high temperatures can damage plants by denaturing enzymes


  True
• Very high light intensity can damage the photosynthetic apparatus
• Increasing carbon dioxide concentration always enhances the rate of photosynthesis

  False
• What happens to the rate of photosynthesis if the temperature becomes too high?

  It decreases
• Higher light intensity always increases the rate of photosynthesis.

  False
• Photosynthesis uses sunlight, water, and carbon dioxide to create oxygen and energy in the form of glucose
• High temperatures can denature enzymes, which reduces the rate of photosynthesis
• Increasing carbon dioxide concentration increases the rate of photosynthesis up to a saturation
• Match the factor with its effect on photosynthesis:

  Light Intensity ↔️ Increases up to a point

  CO2 Concentration ↔️ Increases up to saturation

  Temperature ↔️ Increases up to optimal range

  Water Availability ↔️ Increases with more water
• What happens to photosynthesis when carbon dioxide concentration reaches a saturation point?

  No further increase
• Carbon dioxide is a key reactant in photosynthesis.


  True
• Match the factor with its effect on photosynthesis:

  Light Intensity ↔️ Increases the rate up to a point

  Carbon Dioxide Concentration ↔️ Increases the rate up to saturation

  Temperature ↔️ Increases to optimal range, then decreases

  Water Availability ↔️ Lack of water limits photosynthesis
• As temperature increases, the rate of photosynthesis generally increases because higher temperatures speed up chemical reactions
• Limiting factors restrict the rate of photosynthesis by being in short supply
• Low carbon dioxide levels limit glucose synthesis
• Chlorophyll reflects green light, which gives plants their green color
• What is photosynthesis?

  Creates oxygen and energy
• What is the effect of increasing carbon dioxide concentration on photosynthesis?

  Increases photosynthesis up to a limit
• What happens to the rate of photosynthesis at very high light intensity?

  It decreases
• What is the effect of water availability on photosynthesis?

  Lack of water limits photosynthesis
• As light intensity increases, the rate of photosynthesis continues to increase indefinitely

  False
• Why does increasing CO2 concentration beyond a saturation point not enhance photosynthesis?

  Enzymes reach maximum capacity
• The equation for photosynthesis is: 6CO₂ + 6H₂O + Sunlight → C₆H₁₂O₆ + 6O₂. This equation shows that oxygen is produced as a byproduct
• Why is there a saturation point for CO2 concentration in photosynthesis?

  Enzymes reach maximum capacity
• Water is one of the reactants necessary for photosynthesis.


  True
• Limiting factors restrict the rate of photosynthesis, while optimum conditions are ideal levels of light, carbon dioxide, temperature, and water
• Low light intensity reduces ATP and NADPH production.


  True
• What type of light does chlorophyll absorb most efficiently?

  Blue and red light
• Photosynthesis uses sunlight, water, and carbon dioxide to create oxygen and glucose
• What are the four key factors affecting photosynthesis?

  Light, CO₂, temperature, water
• What happens to photosynthesis at extremely high or low temperatures?

  Rate reduces
• Why does increasing carbon dioxide concentration enhance photosynthesis?

  More glucose production
• High temperatures can denature enzymes involved in photosynthesis.

  True
• Match the pigment with its role in photosynthesis:

  Chlorophyll ↔️ Absorbs light energy

  Carotenoids ↔️ Absorb blue-green light

  Phycobilins ↔️ Absorb green-yellow light
• What type of light do carotenoids absorb?

  Blue-green light
• Why are carotenoids considered accessory pigments in photosynthesis?

  They broaden the light range
• Chlorophyll reflects green
• In the light intensity experiment, what happens to the photosynthesis rate as light intensity increases?

  Increases up to a point