B1.8 - Photosynthesis

• Which of the following absorbs the energy required for photosynthesis?

  Glucose

  Chlorophyll

  Starch

  Chlorophyll
• In what part of the cell does photosynthesis take place?

  In chloroplasts
• What is the word equation for photosynthesis? 

  Carbon dioxide + water ➔ glucose + oxygen
• What is the chemical symbol equation for photosynthesis?

  6CO2 + 6H2O ➔ C6H12O6 + 6O2
• Which type of reaction is photosynthesis?

  • Endothermic
  • Photosynthesis is an endothermic process because it requires energy (from the sun).
• What can the glucose made during photosynthesis be used for?

  • Stored as starch for later
  • Respiration
• What is the molecular formula for glucose?

  C6H12O6
• How do plants get the carbon dioxide required for photosynthesis? 

  It diffuses from the air into the leaves via stomata 
• How do plants get the water required for photosynthesis? 

  It diffuses from the soil into the root hair cells by osmosis
• What makes starch a useful long term storage molecule?

  • It can easily be broken down when needed 
  • It is compact 
  • It is insoluble in water
• One use of glucose is to make amino acids. 

  What else do plants need to make amino acids?

  Nitrate ions
• What are the main uses of glucose in plants? 

  • Cellular respiration - break down the glucose to release energy 
  • Make cellulose - which is used to make strong cell walls
  • Make starch - which is used to store glucose for a later time
  • Make amino acids - which are used to make proteins 
  • Make lipids - these store the energy as fats or oils for later use
• Which useful energy transfer or conversion happens overall in photosynthesis?

  • Light ➔ chemical
  • Photosynthesis converts light energy from the sun into chemical energy in the chemical bonds of glucose molecules. 
• 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 to chloroplasts during photosynthesis?

  By light from the environment
• 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 oxygen for?

  For respiration
• Why is glucose considered essential for plants?

  It is used for energy and growth
• What are the five main uses of glucose in plants?

  • Cellular respiration for energy
  • Making cellulose for cell walls
  • Making starch for storage
  • Making amino acids with nitrate ions
  • Making oils and fats for energy storage
• How does cellular respiration relate to glucose?

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

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

  It is 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
• Why are oils and fats important for plants?

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

  • Light intensity
  • Temperature
  • Carbon dioxide concentration
  • Amount of chlorophyll