Chapter 10 - Chapter 10 - Life on Earth is solar powered. -...

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Chapter 10 - Life on Earth is solar powered. - Photosynthesis – the conversion of light energy to chemical energy that is stored in sugars or other organic compounds; occurs in plants, algae, and certain prokaryotes. - An organism acquires the organic compounds it uses for energy and carbon skeletons by one of two major modes: autotrophic nutrition or heterotrophic nutrition - Autotrophs are “self-feeders”; they sustain themselves without eating anything derived from other living beings. Autotrophs produce their organic molecules from CO 2 and other inorganic raw materials obtained from the environment. - Biologists refer to autotrophs as the producers of the biosphere. - Plants are photoautotrophs , organisms that use light as a source of energy to synthesize organic substances. - Heterotrophs obtain their organic material by the second major mode of nutrition. Unable to make their own food, they live on compounds produced by other organisms. - Heterotrophs are the biosphere’s consumers . - 2 stages of photosynthesis: the light reactions and the Calvin cycle. 10.1 – Photosynthesis converts light energy to the chemical energy of food - Chloroplasts are found mainly in the cells of the mesophyll , the tissue in the interior of the leaf. - Carbon dioxide enters the leaf, and oxygen exits, by way of microscopic pores called stomata. - A chloroplast has an envelope of two membranes surrounding a dense fluid called the stroma. - Suspended within the stroma is a third membrane system, made up of sacs called thylakoids, which segregates the stroma from the thylakoid space inside these sacs. - In some places, thylakoid sacs are stacked in columns called grana . - Chlorophyll , the green pigment that gives leaves their color, resides in the thylakoid membranes of the chloroplast. - It is the light energy absorbed by chlorophyll that drives the synthesis o organic molecules in the chloroplast. - Photosynthesis Equations: 6 CO 2 + 12 H 2 O + Light Energy => C 6 H 12 O 6 + 6 O 2 + 6 H 2 0 6 CO 2 + 6 H 2 O + Light Energy => C 6 H 12 0 6 + 6 0 2 - Light reactions generate NADPH and ATP - Photophosphorylation – the process of generating ATP from ADP and phosphate by means of chemiosmosis, using a proton-motive force generated across the thylakoid membrane of the chloroplast or the membrane of certain prokaryotes during the light reactions of photosynthesis. - The Calvin cycle begins by incorporating CO
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Chapter 10 - Chapter 10 - Life on Earth is solar powered. -...

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