Photosynthesis and respiration

• Word equation for photosynthesis

  Carbon dioxide + water -> glucose + oxygen
• Symbol equation for photosynthesis

  6CO2+ 6H2O → C₆H₁₂O₆ + 6O₂
• What energy do plants use to convert carbon dioxide and water into glucose and oxygen?

  Light
• Where does photosynthesis take place in plants and why?

  Chloroplasts in green plant cells - contain chlorophyll that absorb light energy
• What do plants use glucose for?

  - making cellulose: glucose is converted into cellulose for making strong cell walls

  - converted into sucrose for transport around plant
• How is rate of photosynthesis affected by light?

  Intensity of light affects the amount if energy plant has to carry out photosynthesis

  - as light increases, the level of photosynthesis increases until it is no longer the limiting factor
• How is rate of photosynthesis affected by carbon dioxide?

  It is a raw material needed

  - as carbon dioxide increases, photosynthesis increases
• How is rate of photosynthesis affected by temperature?

  Higher temperature increases kinetic energy of particles, leading to more collisions between reactants and enzymes to form glucose and oxygen

  - affects the speed at which carbon dioxide and water move through plant

  - if the plant gets too hot, the enzymes will be denatured
• How is the plant adapted for photosynthesis?

  Stomata - diffusion of water and carbon dioxide and water into and out of plant

  Transparent and thin upper epidermis - allows light to enter palisade cells

  Thin waxy cuticle - protects leaf without blocking sunlight

  Palisade mesophyll cells have chloroplast: maximizes light absorption which hit chloroplast directly, tall: maximize surface area for absorbing carbon dioxide

  Spongy layer: air spaces which large surface area allow carbon dioxide to diffuse through leaf
• Word equation for aerobic respiration

  glucose + oxygen -> carbon dioxide + water
• Symbol equation for aerobic respiration

  C6H12O6 + 6O2 → 6CO2 + 6H2O
• Word equation for anaerobic respiration in plants

  Glucose —> ethanol + carbon dioxide (+some energy)
• Word equation for anaerobic respiration in animals

  glucose --> lactic acid (+some energy)
• Differences between aerobic and anaerobic respiration

  Aerobic: - requires oxygen, occurs all the time, occurs in mitochondria

  Anaerobic: - without oxygen, incomplete breakdown of glucose, do not transfer as much energy, occurs in cytoplasm