b8

• what is the equation for photosynthesis?

  carbon dioxide + water --> glucose + oxygen

  6CO2 + 6H2O --> C6H12O6 + 6O2
• what is photosynthesis?

  the process by which plants make food using carbon dioxide, water, and light
• what is endothermic reaction?

  a reaction that requies a transfer of engery from the environment

  photosynthesis is an endothermic reaction
• what are the leaf adaptations?

  -broad, a big surface area for light to fall on

  -thin, diffusion distances for the gases are short

  -chlorophll in chloroplasts, so they absorb light

  -veins, bring plenty of water in the xylem to the cells of the leaves & remove the products of photosynthesis in the phloem

  -air spaces, allow carbon dioxide to get to the cells, and oxygen to lave by diffusion

  -guard cells - open and close the stomata to regulate gas exchange
• what is algae?

  -algae are aquatic so the are adapted to photosynthesising in water

  -they have large surface area and absorb carbon dioxide dissolved in the water around them

  -the oxygen they produce also dissolves in the water around them as it is released
• what can rate of photosynthesis be affected by?

  -light intensity

  -temperature

  -level of carbon dioxide

  -amount of chlorophyll
• what is the inverse square law?

  -as distance from plant increases, light intensity decreases - inverse relationship

  -the light intensity decreases in inverse proportion to the square of the distance - doubling the distance results on the light intensity decreasing by a quarter
• how do plants use glucose?

  -plants use some of th eglucose produced during photosynthesis as they respire

  -cellulose cell walls - builds/makes it

  -starch for storage

  -makes amino acids -> proteins

  -to make fats and oils
• why do plants need nitrate ions?

  plants and algal cells need nitrate ions absorbed from the soil or water to make the amino acids used to make proteins