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Photo synthesis : Life from Light and Air. Trapping Energy from Sunlight. The process that uses the sun’s energy to make simple sugars is called photo synthesis. AN OVERVIEW OF PHOTOSYNTHESIS.
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Trapping Energy from Sunlight • The process that uses the sun’s energy to make simple sugars is called photosynthesis.
AN OVERVIEW OF PHOTOSYNTHESIS • Photosynthesis is the process by which autotrophic organisms use light energy to make sugar and oxygen gas from carbon dioxide and water PHOTOSYNTHESIS
Plants are energy producers • Like animals, plants need energy to live • unlike animals, plants don’t need to eat food to make that energy • Plants make both FOOD & ENERGY • animals are heterotrophs(consumers) • plants are autotrophs (producers)
CO2 H2O sugars What do plants need to grow? • The “factory” for trapping energy & making sugars • chloroplast • Fuels • sunlight • carbon dioxide • water • The Products - Oxygen & Glucose The Helpers • Enzymes sun O2 enzymes
light energy 6CO2 + 6H2O + + 6O2 C6H12O6 • Bring In • light • CO2 • H2O • Let Out • O2 • Move Around • sugars leaves shoot roots
CO2 Chloroplasts absorbsunlight & CO2 Leaf sun Leaves Chloroplastsin cell Chloroplast Chloroplast Chloroplasts contain Chlorophyll makeENERGY & SUGAR
Stomates & Guard Cells in the leaf • Function of stomates • CO2 in • O2 out • H2O out • gets to leaves for photosynthesis • Function of guard cells • open & close stomates guard cell stomate
THE LIGHT REACTIONS: CONVERTING SOLAR ENERGY TO CHEMICAL ENERGYVisible radiation drives the light reactions • Certain wavelengths of visible light drive the light reactions of photosynthesis X-rays Micro-waves Radio waves Gammarays UV Infrared Visible light Wavelength (nm)
pigments in the chloroplast • To trap the energy in the sun’s light, the thylakoid membranes contain pigments, molecules that absorb specific wavelengths of sunlight. • Wavelengths that are NOT absorbed are reflected (bounce off) or transmitted (pass through) • So the material in which the pigment is found appears to be the color of the wavelengths that are NOT absorbed Photosynthetic pigments: can absorb light energy & make it available for conversion to chemical energy • . Light Reflectedlight Chloroplast Absorbedlight
pigmentsin the chloroplast • Chlorophyll a: most common pigment in chloroplast (absorbs blue &red light and reflects green light thus giving the chloroplast a green color)(chloro = green phylla + leaf) • Accessory pigments: additional pigments that absorb different wavelengths (carotene, chlorophyll b, & xanthophyll)
Factors Affecting Rate of Photosynthesis • Temperature: increases rate up to a certain point • Light Intensity: increases rate up to a certain point • CO2 level: Increases rate up to a certain point • Water: decrease water, decrease photosynthesis • Minerals; Ex. Magnesium, Nitrogen