plant structures and their functions

• Why would we not be alive without plants?

  Plants are essential for oxygen production
• What is the process of photosynthesis?

  • Converts water and carbon dioxide into oxygen and glucose
  • Requires sunlight as a condition, not a reactant
  • The equation is: $6H_2O +$$6CO_2 \rightarrow 6O_2 +$$C_6H_{12}O_6$
• What is the chemical formula for glucose?

  $C_6H_{12}O_6$
• Why is it important to balance the photosynthesis equation?

  To ensure conservation of mass in reactions
• What happens to the rate of photosynthesis as carbon dioxide levels increase?

  It increases until other factors limit it
• What are the seven requirements for photosynthesis?

  Chlorophyll, water, carbon dioxide, sunlight
• How does temperature affect the rate of photosynthesis?

  Higher temperatures increase the rate until enzymes denature
• What happens to enzymes at high temperatures during photosynthesis?

  They become denatured
• How does light intensity affect photosynthesis?

  Increases photosynthesis until other factors limit it
• What does a flat graph of photosynthesis indicate?

  Photosynthesis continues at a steady rate
• What is the role of glucose in plants after photosynthesis?

  • Stored as starch
  • Example: Potatoes
• What are the main structures in a leaf involved in photosynthesis?

  • Palisade mesophyll: site of photosynthesis
  • Cuticle: waxy layer protecting the leaf
  • Spongy mesophyll: space for gas exchange
  • Guard cells and stomata: regulate transpiration
• What do xylem and phloem transport in plants?

  Xylem carries water; phloem carries food
• How does bright light affect transpiration?

  It increases transpiration rates
• What effect does high humidity have on transpiration?

  It decreases transpiration rates
• What are phototropism and geotropism in plants?

  • Phototropism: growth towards light
  • Geotropism: growth towards gravity
• What are gibberellins and auxins important for?

  Gibberellins for growth; auxins for direction
• What is the role of ethylene in plants?

  It is important for ripening