LIFE 102 Lecture Notes - Lecture 9: Carbon Fixation, Natural Philosophy, Light-Dependent Reactions
30 Sep 2016
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Ps produces food from air (carbon fixation) and powered by sunlight (light reactions) During light reactions ps produces the o2,required from. Heterotrophs: organisms that must obtain food = non-photosynthetic bacteria and protists, animals (including us) and fungi. They are the consumers and decomposers in an ecosystem. Autotrophs: organisms that can produce their own food (by photosynthesis). The producers in an ecosystem are photosynthetic organisms. Johann baptist von helmont: mid 1600s, flemish (belgian) last alchemist and first chemist coined the word gas contemporary of galileo, also put under house arrest by inquisition. The experiment: plant a 5lb willow sprig in 200lb soil, watered the growing plant and waited 5 years. Results: tree weighed 164 lb. , soil lost 2 oz. so knew soil wasn"t eaten by the plant. His conclusion: plants grow by consuming water. (wrong but the fact that it comes from air,
