Topic 2.9:  Photosynthesis

Essential Idea:  Photosynthesis uses the energy in sunlight to produce the chemical energy needed for life.
At SHS, Topic 2.9 is taught in the following class unit(s):

Statements & Objectives:

2.9.U1  Photosynthesis is the production of carbon compounds in cells using light energy.
  • Define photosynthesis.
  • State the chemical equation for photosynthesis.
2.9.U2  Visible light has a range of wavelengths with violet the shortest wavelength and red the longest.
  • Define visible light.
  • State the relationship between wavelength and energy.
  • State the range of wavelengths that fall within the visible spectrum.
2.9.U3  Chlorophyll absorbs red and blue light most effectively and reflects green light more than other colours.
  • Define pigment.
  • State the primary and accessory pigments found in chloroplasts.
  • Explain why plants are green.
2.9.U4  Oxygen is produced in photosynthesis from the photolysis of water.
  • ​Define photolysis.
  • State the equation for photolysis.
  • State that the oxygen produced in photolysis is a waste product of photosynthesis.
2.9.U5  Energy is needed to produce carbohydrates and other carbon compounds from carbon dioxide.
  • State the energy conversion that occurs during photosynthesis.
2.9.U6  Temperature, light intensity and carbon dioxide concentration are possible limiting factors on the rate photosynthesis.
  • Define “limiting factor.”
  • Explain how the following factors limit the rate of photosynthesis:
    • Temperature
    • Light intensity
    • CO2 concentration
2.9.A1  Changes to the Earth’s atmosphere, oceans and rock deposition due to photosynthesis.
  • State that (some) prokaryotes, algae and plants carry out photosynthesis.
  • Define and state evidence for the “Great Oxidation Event.”
2.9.S1  Drawing an absorption spectrum for chlorophyll and an action spectrum for photosynthesis.
  • Distinguish between an action spectrum and an absorption spectrum.
  • Describe the shape of the curve for an absorption spectrum.
  • Describe the shape of the curve for an action spectrum.
2.9.S2  Design an experiment to investigate limiting factors on photosynthesis.
  • ​List mechanism for measuring the rate of photosynthesis.
2.9.S3  Separation of photosynthetic pigments by chromatograph. (Practical 4)
  • Outline the process of separating pigments using chromatography
  • Calculate the Rf value for pigments using pigment chromatography.   ​
2.9.NOS  Experimental design- controlling relevant variables in photosynthesis experiments is essential.
  • Define independent variable, controlled variable and responding variable.
"When we try to pick out anything by itself, we find it hitched to everything else in the Universe."  -  John Muir,   1911