biology p1 - bioenergetics

• What process must a plant carry out to grow and survive?

  Photosynthesis
• Where does photosynthesis take place in a plant?

  In the leaves, specifically chloroplasts
• What pigment in chloroplasts absorbs light?

  Chlorophyll
• What does chlorophyll absorb from the environment?

  Light energy
• What are the reactants in the photosynthesis equation?

  Carbon dioxide and water
• What is the chemical equation for photosynthesis?

  6 CO₂ + 6 H₂O → C₆H₁₂O₆ + 6 O₂
• Why is light written above the reaction line in the photosynthesis equation?

  Because the reaction requires light energy
• What type of reaction is photosynthesis classified as?

  Endothermic reaction
• How is energy transferred from the environment to chloroplasts?

  By light
• How does carbon dioxide enter the leaves?

  Through the stomata
• How is water transported to the leaves?

  Via the xylem
• What is the primary product that plants want from photosynthesis?

  Glucose
• What do plants sometimes use the oxygen produced for?

  For respiration
• What are the five main uses of glucose in plants?

  Respiration, cellulose, starch, amino acids, oils
• How does respiration relate to glucose in plants?

  It breaks glucose apart to release energy
• What is cellulose made from?

  Combined glucose molecules
• Why is starch a better form of glucose for storage?

  It's more compact and insoluble
• When do plants typically break down starch to glucose?

  When photosynthesis isn't happening much
• How do plants make amino acids?

  By combining glucose with nitrate ions
• What do plants use amino acids to make?

  Proteins
• What is the purpose of oils and fats in plants?

  Stored as future energy resources
• What factors affect the rate of photosynthesis?

  Light intensity, temperature, CO₂ concentration, chlorophyll amount
• What is the relationship between photosynthesis and plant growth rate?

  Growth rate depends on photosynthesis speed
• What are the main products of photosynthesis and their uses?

  • Glucose: energy source, building blocks
  • Oxygen: used for respiration
  • Starch: long-term energy storage
  • Cellulose: strengthens cell walls
  • Amino acids: protein synthesis
  • Oils and fats: energy reserves
• What do plants need to carry out photosynthesis?

  Light, carbon dioxide, temperature, chlorophyll
• How does chlorophyll affect photosynthesis?

  Less chlorophyll means less photosynthesis
• What can cause variations in chlorophyll levels in plants?

  Disease, environmental stress, lack of nutrients
• What are the limiting factors for photosynthesis?

  Light, carbon dioxide, temperature
• What is plotted on the x-axis of photosynthesis graphs?

  Light, carbon dioxide, temperature
• What happens to the rate of photosynthesis as light intensity increases?

  The rate of photosynthesis increases
• What does it mean when the graph of photosynthesis plateaus?

  Another factor is limiting photosynthesis
• How does carbon dioxide concentration affect photosynthesis?

  Higher concentration increases the rate
• What happens to the rate of photosynthesis at high temperatures?

  It initially increases, then decreases
• At what temperature do enzymes involved in photosynthesis denature?

  About 45 degrees Celsius
• What is shown when two curves are plotted on a graph of photosynthesis?

  Different experiments under varying conditions
• How can comparing two curves on a graph indicate a limiting factor?

  It shows which condition affects photosynthesis
• What do farmers do to create optimal conditions for photosynthesis?

  Use greenhouses, artificial light, and CO2
• Why do farmers use greenhouses?

  To trap heat and increase temperature
• What is a benefit of using fertilizers in farming?

  Ensures plants have essential minerals
• What must farmers consider when increasing crop yield?

  Cost versus extra yield from crops