1.3 Photosynthesis

• What is the overall (summary) word equation for photosynthesis?

  carbon dioxide + water -> sugar + oxygen
• What is the name of the pigment that traps light energy and in what part of a plant cell is it found?

  chlorophyll, in the chloroplast
• Describe what happens during the stage 1 of photosynthesis (the light reactions).

  Light energy is converted into chemical energy:

  1) Water is split to produce hydrogen and oxygen.

  2) The energy released is used to generate ATP

  3) Oxygen diffuses from the cell through the stomata
• Which two products of the light reactions are required for stage 2 of photosynthesis (carbon fixation)?

  ATP and hydrogen
• What is carbon fixation (stage 2 of photosynthesis)?

  A series of enzyme-controlled reactions, which uses hydrogen and carbon dioxide from stage 1 binds together, ATP (produced by the light reactions) used as energy, to produce sugar.
• What happens to the chemical energy in the sugar that is produced during photosynthesis?

  1) Some of it is used for respiration

  2) Some of it is turned into a structural carbohydrate (cellulose)

  3) Some of it is turned into a storage carbohydrate (starch)
• Name an example of a limiting factor for photosynthesis

  1) carbon dioxide concentration

  2) light intensity

  3) temperature