Chapter 6 Energy and Metabolism PDF

Unit 3 Chapter 6 Chapter 7 Chapter 8 Exam 11/08 © 2020 McGraw-Hill Education. 6-1 Chapter 6: Energy and Metabolism © 2020 McGraw-Hill Education. 6-2  6.1 The Flow of Energy in Living Systems Learning Outcomes 1. Differentiate...

Unit 3 Chapter 6 Chapter 7 Chapter 8 Exam 11/08 © 2020 McGraw-Hill Education. 6-1 Chapter 6: Energy and Metabolism © 2020 McGraw-Hill Education. 6-2  6.1 The Flow of Energy in Living Systems Learning Outcomes 1. Differentiate between kinetic and potential energy. 2. Identify the source of energy for the biosphere. 3. Describe the nature of redox reactions. © 2020 McGraw-Hill Education. 6-3  Energy Photo credit:NASA/GSFC/SDO © 2020 McGraw-Hill Education. 6-4  Potential vs Kinetic Energy Figure 6.1 © 2020 McGraw-Hill Education. 6-5  Energy Flow Through an Ecosystem oto source: https://www.tutorialspoint.com/environmental_studies/environmental_studies_energy_flow_in_ecosystem.htm © 2020 McGraw-Hill Education. 6-6  Oxidation and Reduction (Redox) Figure 6.2 © 2020 McGraw-Hill Education. 6-7  6.2 The Laws of Thermodynamics and Free Energy Learning Outcomes 1. Explain the laws of thermodynamics. 2. Relate free energy changes to the outcome of chemical reactions. 3. Contrast the course of a reaction with and without an enzyme catalyst. © 2020 McGraw-Hill Education. 6-8 First Law of Thermodynamics E = mc 2 © 2020 McGraw-Hill Education. 6-9  Second Law of Thermodynamics Photo source: https://commons.wikimedia.org/wiki/File:Figure_06_02_02.jpg © 2020 McGraw-Hill Education. 6-10  Gibbs Free Energy G = Energy available to do work G = H−TS H = enthalpy, energy in a molecule’s chemical bonds. T = absolute temperature. S = entropy, unavailable energy. © 2020 McGraw-Hill Education. 6-11 ∆G = ∆H − T∆S a. Endergonic reaction b. Exergonic reaction Figure 6.4 © 2020 McGraw-Hill Education. 6-12  Activation Energy of Reaction Photo Source: https://sites.google.com/site/keremschemistrynotesib2/chapter-6--kinematics/6-1- activation-energy © 2020 McGraw-Hill Education. 6-13  Catalysts and Activation Energy Figure 6.5 © 2020 McGraw-Hill Education. 6-14  6.3 ATP: The Energy Currency of Cells Learning Outcomes 1. Describe the role of ATP in short-term energy storage. 2. Distinguish which bonds in ATP are “high energy.” © 2020 McGraw-Hill Education. 6-15  ATP Molecule Figure 6.6 © 2020 McGraw-Hill Education. 6-16  ATP Cycle Figure 6.7 © 2020 McGraw-Hill Education. 6-17  6.4 Enzymes: Biological Catalysts Learning Outcomes 1. Discuss the specificity of enzymes. 2. Explain how enzymes bind to their substrates. 3. List the factors that influence the rate of enzyme-catalyzed reactions. © 2020 McGraw-Hill Education. 6-18  Enzyme Binding Figure 6.8 © 2020 McGraw-Hill Education. 6-19 Catalytic Cycle of Enzymes © 2020 McGraw-Hill Education. 6-20  Forms of enzymes Enzymes may be suspended in the cytoplasm or attached to cell membranes and organelles Multienzyme complexes – subunits work together to carry out a series of reactions. Advantages include: Product of one reaction can be delivered easily to next enzyme (don’t have to wait float by). Unwanted side reactions prevented because the substrate doesn’t leave the complex. All reactions can be controlled as a unit. © 2020 McGraw-Hill Education. 6-21  Nonprotein enzymes Ribozymes are RNA catalysts. Two kinds: 1. Intramolecular catalysis – catalyze reaction on RNA molecule itself 2. Intermolecular catalysis – RNA acts on another molecule © 2020 McGraw-Hill Education. 6-22  Enzymes and the Environment Figure 6.12 © 2020 McGraw-Hill Education. 6-23  Enzyme Inhibition Figure 6.13 © 2020 McGraw-Hill Education. 6-24  Allosteric enzymes Allosteric enzymes – most enzymes can exist in active and inactive forms Most noncompetitive inhibitors bind to allosteric site – chemical on/off switch Allosteric inhibitor – binds to allosteric site and reduces enzyme activity Allosteric activator – binds to allosteric site and increases enzyme activity © 2020 McGraw-Hill Education. 6-25 Enzyme Cofactors and Coenzymes Cofactors – chemical components that assist enzyme function Coenzymes – cofactors that are nonprotein organic molecules © 2020 McGraw-Hill Education. 6-26  6.5 Metabolism: The Chemical Description of Cell Function Learning Outcomes 1. Explain the kinds of reactions that make up metabolism. 2. Discuss what is meant by a metabolic pathway. 3. Recognize that metabolism is a product of evolution. © 2020 McGraw-Hill Education. 6-27  Metabolism Metabolism is the total of all chemical reactions carried out by an organism. Anabolic reactions/anabolism Expend energy to build up molecules (e.g., dehydration synthesis) Catabolic reactions/catabolism Harvest energy by breaking down molecules (e.g., hydrolysis) © 2020 McGraw-Hill Education. 6-28 Biochemical Pathway © 2020 McGraw-Hill Education. 6-29  Biochemical Pathway Evolution CDEF + H G 4 3 2 1 © 2020 McGraw-Hill Education. 6-30 Feedback Inhibition © 2020 McGraw-Hill Education. 6-31