Essential Idea:  Photosynthesis uses the energy in sunlight to produce the chemical energy needed for life.

• Outline answer to each objective statement for topic 2.9 (coming soon)
• Quizlet study set for this topic

At SHS, Topic 2.9 is taught in the following class unit(s):​​

• ​Light and Pigments (unit 34A)
• Photosynthesis (unit 34B)

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.

In the News:

• Scientists Have 'Hacked Photosynthesis' In Search Of More Productive Crops (2019-01-03)
• ​How plants bind their green pigment chlorophyll (2018-10-18)
• Photosynthesis by marine algae produces sound (2018-10-03)
• ​​Hot-spring bacteria reveal ability to use far-red light for photosynthesis (2014-08-21)
• Blue leaves help plants get extra energy from sun (2016-10-24)
• Why Does Fall Foliage Turn So Red and Fiery? It Depends. (2016-10-25)
• Explaining the Other Side of Autumn Leaves (2016-11-21)
• Springtime for the artificial leaf (2014-06-04)
• ​Life forms appeared at least 60 million years earlier than previously thought (2014-09-04)​
• Iron toxicity for cyanobacteria delayed oxygen accumulation in early Earth's atmosphere (2015-01-05)
• Humble moss helped create our oxygen-rich atmosphere (2016-08-15)
• Will the artificial leaf sprout to combat climate change? (2016-11-21)