plants and photosynthesis

• What is photosynthesis?

  Process plants use to make carbohydrates
• What raw materials do plants use in photosynthesis?

  Carbon dioxide and water
• What energy source do plants use during photosynthesis?

  Energy from light
• What substance absorbs light energy in plants?

  Chlorophyll
• Where is chlorophyll found in plants?

  In chloroplasts of palisade cells
• What sugar is produced during photosynthesis?

  Glucose
• What is released as a by-product of photosynthesis?

  Oxygen
• What is the equation summarizing photosynthesis?

  • Light + Carbon dioxide + Water → Glucose + Oxygen
• What is the process by which plants make carbohydrates from raw materials using energy from light?

  Photosynthesis
• What are the raw materials used in photosynthesis?

  Carbon dioxide and water
• What is the role of chlorophyll in photosynthesis?

  It absorbs light energy
• What is the by-product of photosynthesis?

  Oxygen
• What happens to the glucose produced during photosynthesis?

  Some is used for respiration, some is converted into starch for storage
• What is the limiting factor of photosynthesis?

  The factor working at the lowest level
• How does temperature affect the rate of photosynthesis?

  The rate increases as temperature rises, but decreases if too high due to enzyme denaturation
• How does light intensity affect the rate of photosynthesis?

  Increasing light intensity increases the rate of photosynthesis, up to a maximum rate
• What is the inverse square law for light intensity?

  Light intensity is inversely proportional to the square of the distance from the source
• How can you calculate light intensity using the inverse square law?

  Light intensity α $1/\text{distance}^2$
• What is the SI unit for light intensity?

  Lux
• How can you test if a plant has been photosynthesizing?

  Test the leaf to see if starch is present
• What are the steps of the photosynthesis process?

  1. Light energy is absorbed by chlorophyll
  2. Light energy is used to convert carbon dioxide and water into glucose
  3. Oxygen is released as a by-product
  4. Glucose is:

  • Transported to growing parts for respiration
  • Transformed into cellulose, proteins, and oils
  • Turned into starch for storage
• How does the function of a light microscope differ from a scanning electron microscope (SEM)?

  Light microscopes produce 2D images, while SEMs produce 3D images
• What are the strengths and weaknesses of using light microscopes compared to electron microscopes?

  Strengths of light microscopes:

  • Cheaper and more accessible
  • Can be used to observe living specimens

  
  

  Weaknesses of light microscopes:

  • Lower resolution (0.2 μm limit)
  • Cannot observe very small structures
• How does the inverse square law apply to light intensity?

  • Light intensity is inversely proportional to the square of the distance from the source
  • When distance doubles, light intensity decreases to 1/4 of the original value
  • This can be calculated using the formula: Light intensity α 1/distance^2
• If a light is moved twice as far from a photosynthesizing plant, how will the light intensity change?

  It will decrease to 1/4 of the original value
• What factors can limit the rate of photosynthesis?

  • Temperature (optimum temperature, denaturation at high temps)
  • Light intensity (increasing intensity increases rate up to a maximum)
  • Carbon dioxide concentration