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Chapter 8 – Cellular Energy Section 1 – How Organisms Obtain Energy
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All living organisms use energy to carry out all biological processes. How Organisms Obtain Energy Cellular Energy Section 1
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Transformation of Energy Energy is the ability to do work. How Organisms Obtain Energy Cellular Energy Thermodynamics is the study of the flow and transformation of energy in the universe. Section 1
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Laws of Thermodynamics 1 st Law—Law of Conservation of Energy Energy can be converted from one form to another, but it cannot be created nor destroyed. How Organisms Obtain Energy Cellular Energy 2 nd Law—energy cannot be converted without the loss of usable energy. Energy that is lost is generally converted to thermal energy. Entropy is the measure of unusable energy in a system. (food chain) Section 1
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Autotrophs and Heterotrophs Autotrophs - organisms that make their own food, most through photosynthesis (plants). How Organisms Obtain Energy Cellular Energy Heterotrophs - organisms that need to ingest food to obtain energy (humans). Section 1
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Metabolism All of the chemical reactions in a cell. A metabolic pathway is a series of chemical reactions in which the product of one reaction is the substrate for the next reaction. How Organisms Obtain Energy Cellular Energy Section 1
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Metabolism 2 types of metabolic pathways: Catabolic – release energy by breaking down larger molecules into smaller molecules. Anabolic – use energy released by catabolic pathways to build larger molecules from smaller molecules. Results in a continuous flow of energy within an organism. How Organisms Obtain Energy Cellular Energy Section 1
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Photosynthesis is an anabolic pathway –Light energy from the sun is converted to chemical energy (glucose) for use by the cell. Cellular respiration is a catabolic pathway –Organic molecules are broken down to release energy (in the form of ATP) for use by the cell. How Organisms Obtain Energy Metabolism
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ATP: The Unit of Cellular Energy Adenosine Triphosphate (ATP) ATP is the most abundant energy- carrier molecule in cells. All chemical reactions that occur in a cell use ATP as the energy source. How Organisms Obtain Energy Cellular Energy Section 1
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ATP: The Unit of Cellular Energy ATP is synthesized by cells through the process of cellular respiration. Made up of an adenine base, ribose sugar, and 3 phosphate groups. How Organisms Obtain Energy Cellular Energy Section 1
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ATP: The Unit of Cellular Energy ATP releases energy when the bond between the second and third phosphate group is broken. Forms a molecule called ADP and a free phosphate group. https://www.youtube.com/watch?v=JeGx2N alhtg How Organisms Obtain Energy Cellular Energy Section 1
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ATP: The Unit of Cellular Energy How Organisms Obtain Energy Cellular Energy Section 1
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