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Photosynthesis. Yr 11 Biology Miss Brunott. http://www.fun-with-science.com/fun_wi7.gif. What is Photosynthesis?. Involves the process where light energy from the sun is converted into chemical energy. Carbon from CO 2 is fixed into organic compounds (glucose). .
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Photosynthesis Yr 11 Biology Miss Brunott http://www.fun-with-science.com/fun_wi7.gif
What is Photosynthesis? • Involves the process where light energy from the sun is converted into chemical energy. • Carbon from CO2 is fixed into organic compounds (glucose).
http://grapevine.net.au/~grunwald/une/KLAs/science/irrigation-photosynthesis.gifhttp://grapevine.net.au/~grunwald/une/KLAs/science/irrigation-photosynthesis.gif
Equation for Photosynthesis Sunlight 6CO2 + 6H2O C6H12O6 + 6O2 Chlorophyll
Light Spectrum of Photosynthesis • Normal light is a mixture of wavelengths represented by seven colours – ROY G BIV. • Most plants are green as green light is reflected off them. • Plants contain the green pigment chlorophyll – use the blue and red wavelengths of the light spectrum.
http://www.sciencebuddies.org/mentoring/project_ideas/HumBeh_img019.gifhttp://www.sciencebuddies.org/mentoring/project_ideas/HumBeh_img019.gif
Step 1: Light Dependent Reactions • The chlorophyll pigments absorb light energy. • The energy excites electrons and releases it from the molecule. • The electron is used for producing ATP and break water molecules into hydrogen and oxygen molecules.
Step 1: Light Dependent Reactions • The oxygen is released as a waste from the plant. • Once electrons have used their energy, return back to chlorophyll molecules.
Step 2: Light-Independent Reactions • Takes place in the stroma. • Does not require light. • Require the products of light-dependent reactions. • The hydrogen (from light-dependent) combines with CO2 (from atmosphere). • Uses ATP energy and produces glucose.
Complexity of Photosynthesis http://fig.cox.miami.edu/~cmallery/150/phts/c8.10x21.overview.jpg
Factors Affecting Photosynthesis • Photosynthesis stops or slows down if the conditions are quite right. • A limiting factor is something that stops photosynthesis from happening any faster. • Limiting factors depend on environmental factors – climate etc.
Factors Affecting Photosynthesis • Light Intensity • Increase light – increase photosynthesis • Only 1% of light is used • Temperature • Increase Temperature – increase photosynthesis • Max 40 degrees
Factors Affecting Photosynthesis • Water • Decrease water cause stomata to close no CO2 will enter • Carbon Dioxide • Increase CO2, increases photosynthesis • Reaches a compensation point