Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Dee Unglaub Silverthorn, Ph.D. H UMAN P HYSIOLOGY PowerPoint ® Lecture Slide Presentation by Dr. Howard D. Booth, Professor of Biology, Eastern Michigan University AN INTEGRATED APPROACH T H I R D E D I T I O N Chapter 4 Cellular Metabolism
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings About this Chapter Energy for synthesis and movement Energy transformation Enzymes and how they speed reactions Metabolic pathways ATP its formation and uses in metabolism Synthesis of biologically important molecules
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Energy does work Kinetic energy Potential energy Energy conversion Energy (E) Transfer Overview
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Energy (E) Transfer Overview Figure 4-1: Energy transfer in the environment
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Chemosynthesis versus Photosynthesis Chemosynthesis 6CO 2 + 6H 2 S → C 6 H 12 O 6 + 6S Needs heat added such as from hydrothermal vents in the deep ocean Photosynthesis 2n CO 2 + 2n H 2 O + photons → 2(CH 2 O) n + 2n O 2photons2(CH 2 O) n Occurs in Two Stages Stage 1: Light energy used to form ATP and NADPH Stage 2: Uses ATP and NADPH to reduce CO 2
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Energy and Chemical Reactions Figure 4-5: Energy transfer and storage in biological reactions
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Adenosine Triphosphate (ATP) Source of immediately usable energy for the cell Adenine-containing RNA nucleotide with three phosphate groups
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Adenosine Triphosphate (ATP) Figure 2.22
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings How ATP Drives Cellular Work Figure 2.23
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Protein Figure 2.16 Macromolecules composed of combinations of 20 types of amino acids bound together with peptide bonds
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Structural Levels of Proteins Primary – amino acid sequence Secondary – alpha helices or beta pleated sheets
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Structural Levels of Proteins Figure 2.17a-c
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Structural Levels of Proteins Tertiary – superimposed folding of secondary structures Quaternary – polypeptide chains linked together in a specific manner
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Structural Levels of Proteins Figure 2.17d, e
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Fibrous and Globular Proteins Fibrous proteins Extended and strandlike proteins Examples: keratin, elastin, collagen, and certain contractile fibers Globular proteins Compact, spherical proteins with tertiary and quaternary structures Examples: antibodies, hormones, and enzymes
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Protein Synthesis Figure 4-34: Summary of transcription and translation
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Post – Translational protein modificaiton Figure 4-35: Post-translational modification and the secretory pathway
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Folding, cleavage, additions: glyco- lipo- proteins Post – Translational protein modificaiton
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Characteristics of Enzymes Most are globular proteins that act as biological catalysts Holoenzymes consist of an apoenzyme (protein) and a cofactor (usually an ion) Enzymes are chemically specific Frequently named for the type of reaction they catalyze Enzyme names usually end in -ase Lower activation energy
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Characteristics of Enzymes Figure 2.19
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Enzymes speed biochemical reactions Figure 4-8: Two models of enzyme binding sites
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Mechanism of Enzyme Action Enzyme binds with substrate Product is formed at a lower activation energy Product is released
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Lower activation E Specific Cofactors Modulators Acidity Temperature Competitive inhibitors Allosteric Concentrations Enzymes speed biochemical reactions
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Protein Denaturation Figure 2.18a Reversible unfolding of proteins due to drops in pH and/or increased temperature
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Protein Denaturation Figure 2.18b Irreversibly denatured proteins cannot refold and are formed by extreme pH or temperature changes
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Defined: Equlibrium Reversible Law of Mass Action Figure 4-17: Law of mass action
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Oxidation–reduction Hydrolysis–dehydration Addition–subtraction exchange Ligation Types of Enzymatic Reactions
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Pathways Intermediates Catabolic - energy Anabolic - synthesis Cell Metabolism Figure 4-18b: A group of metabolic pathways resembles a road map
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Feedback inhibition Control of Metabolic Pathways Figure 4-19: Feedback inhibition
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Glycolysis Pyruvate Anaerobic respiration Lactate production 2 ATPs produced ATP Production Figure 4-21: Overview of aerobic pathways for ATP Production
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Aerobic respiration In mitochondria Acetyl CoA and CO 2 Citric Acid Cycle or Kreb’s Cycle or TCA Cycle Energy Produced from 1 Acetyl CoA 1 ATP 3 NADH 1 FADH2 Waste–2 CO 2 s Pyruvate Metabolism
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Pyruvate Metabolism Figure 4-23: Pyruvate metabolism
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings High energy electrons Energy transfer ATP synthesized from ADP H 2 O is a byproduct- In a typical individual this amounts to approximately 400 ml/day Electron Transport
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Electron Transport Figure 4-25: The electron transport system and ATP synthesis
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Complex Carbohydrates Glycogen catabolism Liver storage Muscle storage Glucose produced Biomolecules Catabolized to make ATP Figure 4-26: Glycogen catabolism
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Deaminated Conversion Glucose Acetyl CoA Protein Catabolism
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Protein Catabolism Figure 4-27: Protein catabolism and deamination
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Higher energy content Triglycerides to glycerol Glycerol Fatty acids Ketone bodies - liver Lipid Catabolism
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Fat mass, adipose tissue and energy stores Data for a 70 kg lean subject. Adipose tissue triglycerides = 120,000 kcal Muscle triglycerides = 3000 kcal Liver triglycerides = 450 kcal Liver glycogen = 400 kcal Muscle glycogen = 2500 kcal
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Glycogen synthesis Liver storage Glucose to glycogen Gluconeogenesis Amino acids Glycerol Lactate Synthetic (Anabolic) pathways Figure 4-29: Gluconeogenesis
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Acetyl Co A Glycerol Fatty acids Triglycerides Lipogenesis Figure 4-30: Lipid synthesis
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Lipogenesis Figure 4-30: Lipid synthesis
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Energy: chemical, transport, mechanical work Reactions: reactants, activation energy, directions Enzymes: characteristics, speed & control pathways Metabolism: catabolic, anabolic ATP production: anaerobic, aerobic, glycolysis, citric acid cycle, & electron transport Synthesis of carbohydrates, lipids and proteins Summary