This chapter presents the following content: An organism’s metabolism transforms matter and energy, subject to the laws of thermodynamics, the free-energy change of a reaction tells us whether the reaction occurs spontaneously, ATP powers cellular work by coupling exergonic reactions to endergonic reactions,.and another contents. | Chapter 8 An Introduction to Metabolism Overview: The Energy of Life The living cell Is a miniature factory where thousands of reactions occur Converts energy in many ways Some organisms Convert energy to light, as in bioluminescence Figure Concept : An organism’s metabolism transforms matter and energy, subject to the laws of thermodynamics Metabolism Is the totality of an organism’s chemical reactions Arises from interactions between molecules Organization of the Chemistry of Life into Metabolic Pathways A metabolic pathway has many steps That begin with a specific molecule and end with a product That are each catalyzed by a specific enzyme Enzyme 1 Enzyme 2 Enzyme 3 A B C D Reaction 1 Reaction 2 Reaction 3 Starting molecule Product Catabolic pathways Break down complex molecules into simpler compounds Release energy Anabolic pathways Build complicated molecules from simpler ones Consume energy Forms of Energy Energy Is the capacity to cause change Exists in various forms, of which some can perform work Kinetic energy Is the energy associated with motion Potential energy Is stored in the location of matter Includes chemical energy stored in molecular structure Energy can be converted From one form to another On the platform, a diver has more potential energy. Diving converts potential energy to kinetic energy. Climbing up converts kinetic energy of muscle movement to potential energy. In the water, a diver has less potential energy. Figure The Laws of Energy Transformation Thermodynamics Is the study of energy transformations The First Law of Thermodynamics According to the first law of thermodynamics Energy can be transferred and transformed Energy cannot be created or destroyed An example of energy conversion Figure First law of thermodynamics: Energy can be transferred or transformed but Neither created nor destroyed. For example, the chemical (potential) energy in food will be converted to the kinetic energy of the cheetah’s movement in (b). | Chapter 8 An Introduction to Metabolism Overview: The Energy of Life The living cell Is a miniature factory where thousands of reactions occur Converts energy in many ways Some organisms Convert energy to light, as in bioluminescence Figure Concept : An organism’s metabolism transforms matter and energy, subject to the laws of thermodynamics Metabolism Is the totality of an organism’s chemical reactions Arises from interactions between molecules Organization of the Chemistry of Life into Metabolic Pathways A metabolic pathway has many steps That begin with a specific molecule and end with a product That are each catalyzed by a specific enzyme Enzyme 1 Enzyme 2 Enzyme 3 A B C D Reaction 1 Reaction 2 Reaction 3 Starting molecule Product Catabolic pathways Break down complex molecules into simpler compounds Release energy Anabolic pathways Build complicated molecules from simpler ones Consume energy Forms of Energy Energy Is the capacity to cause change Exists in various forms, of
