Topic 2.9 – Photosynthesis Understandings  Photosynthesis is the production of carbon compounds in cells using light energy.  Visible light has a range of wavelengths with violet the shortest wavelength and red the longest.  Chlorophyll absorbs red and blue light most effectively and reflects green light more than other colours.  Oxygen is produced in photosynthesis from the photolysis of water.  Energy is needed to produce carbohydrates and other carbon compounds from carbon dioxide.  Temperature, light intensity and carbon dioxide concentration are possible limiting factors on the rate of photosynthesis.

Topic 2.8 – Photosynthesis Skills and Applications  Application: Changes to the Earth’s atmosphere, oceans and rock deposition due to photosynthesis.  Skill: Drawing an absorption spectrum for chlorophyll and an action spectrum for photosynthesis.  Skill: Design of experiments to investigate the effect of limiting factors on photosynthesis.  Skill: Separation of photosynthetic pigments by chromatograph (Prac. 4)

Energy Flow Through Ecosystems  Energy enters ecosystems mainly through photosynthesis  energy stored in the chemical bonds of sugar molecules  produce food using nonliving nutrients and sunlight  Autotrophs: have the ability to make their own organic molecules  PHOTOSYNTHESIS – uses light energy and inorganic molecules to produce organic molecules  CHEMOSYNTHESIS – uses inorganic molecules such as hydrogen sulfide to produce organic molecules (instead of sunlight) Sugar is synthesized and used in plant tissues plant tissues, growth Energy is captured from sunlight Carbon dioxide is absorbed from the air Oxygen is released Water is absorbed from soil, used in photosynthesis, and stored in cells Inorganic mineral nutrients (nitrate, phosphate) are absorbed from soil and used in plant tissues photosynthesis

O2O2 CO 2 H2OH2O sugar plant tissues other nutrients energy from sunlight photosynthesis Photosynthesis Fig. 28-1

Electromagnetic Spectrum

Light Dependent Reactions

Light Independent Reactions  6CO 2 + 6H 2 O => C 6 H O 2