Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Fundamentals of Anatomy & Physiology SIXTH EDITION Frederic H. Martini PowerPoint ® Lecture Slide Presentation prepared by Dr. Kathleen A. Ireland, Biology Instructor, Seabury Hall, Maui, Hawaii Chapter 25, part 1 Metabolism and Energetics
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Learning Objectives Explain why cells need to synthesis new organic components Describe the basic steps in glycolysis, the TCA cycle, and the electron transport chain Summarize the energy yield of glycolysis and cellular respiration Describe the pathways involved in lipid, protein and nucleic acid metabolism
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Learning Objectives Summarize the characteristics of the absorptive and postabsorptive metabolic states Explain what constitutes a balanced diet and why such a diet is important Define metabolic rate and discuss the factors involved in determining an individual’s BMR
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 25-1 An Overview of Metabolism
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Metabolism is all the chemical reactions that occur in an organism Cellular metabolism Cells break down excess carbohydrates first, then lipids Cells conserve amino acids 40% of the energy released in catabolism is captured in ATP Rest is released as heat Metabolism
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 25.1 Figure 25.1 An Introduction to Cellular Metabolism
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Performance of structural maintenance and repairs Support of growth Production of secretions Building of nutrient reserves Anabolism
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 25.2 Figure 25.2 Metabolic Turnover and Cellular ATP Production
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings cells provide small organic molecules for their mitochondria Mitochondria produce ATP used to perform cellular functions Cells and Mitochondria
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 25.3 Nutrient Use in Cellular Metabolism Figure 25.3
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 25-2 Carbohydrate Metabolism
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Glycolysis One molecule of glucose = two pyruvate ions, two ATP, two NADH Aerobic metabolism (cellular respiration) Two pyruvates = 34 ATP The chemical formula for this process is C 6 H 12 O O 2 6 CO H 2 O Most cells generate ATP through the breakdown of carbohydrates
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The breakdown of glucose to pyruvic acid This process requires: Glucose molecules Cytoplasmic enzymes ATP and ADP Inorganic phosphate NAD (nicotinamide adenine dinucleotide) The overall reaction is: Glucose + 2 NAD + 2 ADP + 2P i 2 Pyruvic acid + 2 NADH + 2 ATP Glycolysis
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 25.4 Glycolysis Animation: Steps in Glycolysis PLAY Figure 25.4
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 25.4 Glycolysis Figure 25.4
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Pyruvic acid molecules enter mitochondria Broken down completely in TCA cycle Decarboxylation Hydrogen atoms passed to coenzymes Oxidative phosphorylation Mitochondrial ATP Production (cellular respiration)
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 25.5 The TCA Cycle Animation: TCA Cycle PLAY Figure 25.5
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 25.5 The TCA Cycle Figure 25.5a
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 25.5 The TCA Cycle Figure 25.5b
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Requires coenzymes and consumes oxygen Key reactions take place in the electron transport system (ETS) Cytochromes of the ETS pass electrons to oxygen, forming water The basic chemical reaction is: 2 H 2 + O 2 2 H 2 O Oxidative phosphorylation and the ETS
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 25.6 Oxidative Phosphorylation Figure 25.6 Animation: Chemiosmosis PLAY
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 25.6 Oxidative Phosphorylation Figure 25.6a
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 25.6 Oxidative Phosphorylation Figure 25.6b
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Per molecule of glucose entering these pathways Glycolysis – has a net yield of 2 ATP Electron transport system – yields approximately 28 molecules of ATP TCA cycle – yields 2 molecules of ATP Energy yield of glycolysis and cellular respiration
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 25.7 Figure 25.7 A Summary of the Energy Yield of Aerobic Metabolism
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Gluconeogenesis Synthesis of glucose from noncarbohydrate precursors Lactic acid, glycerol, amino acids Liver cells synthesis glucose when carbohydrates are depleted Glycogenesis Formation of glycogen Glucose stored in liver and skeletal muscle as glycogen Important energy reserve Synthesis of glucose and glycogen
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 25.8 Figure 25.8 Carbohydrate Breakdown and Synthesis