Biochemistry 2/e - Garrett & Grisham CHAPTER 1 Chemistry is the Logic of Biological Phenomena to accompany Biochemistry, 2/e by Reginald Garrett and Charles Grisham All rights reserved. Requests for permission to make copies of any part of the work should be mailed to: Permissions Department, Harcourt Brace & Company, 6277 Sea Harbor Drive, Orlando, Florida 32887-6777 Biochemistry 2/e - Garrett & Grisham Outline • 1.1 Distinctive Properties of Living Systems • 1.2 Biomolecules: Molecules of Life • 1.3 Biomolecular Hierarchy • 1.4 Properties of Biomolecules • 1.5 Organization and Structure of Cells • 1.6 Viruses as Cell Parasites Biochemistry 2/e - Garrett & Grisham On Life and Chemistry... • “Living things are composed of lifeless molecules” (Albert Lehninger) • “Chemistry is the logic of biological phenomena” (Garrett and Grisham) Biochemistry 2/e - Garrett & Grisham 1.1 Distinctive Properties of Living Systems • Organisms are complicated and highly organized • Biological structures serve functional purposes • Living systems are actively engaged in energy transformations • Living systems have a remarkable capacity for self-replication Biochemistry 2/e - Garrett & Grisham Biochemistry 2/e - Garrett & Grisham Biochemistry 2/e - Garrett & Grisham Biochemistry 2/e - Garrett & Grisham 1.2 Biomolecules: The Molecules of Life H, O, C and N make up 99+% of atoms in the human body ELEMENT Oxygen Hydrogen Carbon Nitrogen PERCENTAGE 63 25.2 9.5 1.4 Biochemistry 2/e - Garrett & Grisham 1.2 Biomolecules: The Molecules of Life • What property unites H, O, C and N and renders these atoms so appropriate to the chemistry of life? • Answer: Their ability to form covalent bonds by electron-pair sharing. Biochemistry 2/e - Garrett & Grisham 1.2 Biomolecules: The Molecules of Life What are the bond energies of covalent bonds? Bond Energy kJ/mol H-H 436 C-H 414 C-C 343 C-O 351 Biochemistry 2/e - Garrett & Grisham Biochemistry 2/e - Garrett & Grisham Biochemistry 2/e - Garrett & Grisham 1.3 A Biomolecular Hierarchy Simple Molecules are the Units for Building Complex Structures • • • • Metabolites and Macromolecules Organelles Membranes The Unit of Life is the Cell Biochemistry 2/e - Garrett & Grisham Biochemistry 2/e - Garrett & Grisham 1.4 Properties of Biomolecules Reflect Their Fitness to the Living Condition • Macromolecules and Their Building Blocks Have a “Sense” or Directionality • Macromolecules are Informational • Biomolecules Have Characteristic Three-Dimensional Architecture • Weak Forces Maintain Biological Structure and Determine Biomolecular Interactions Biochemistry 2/e - Garrett & Grisham Biochemistry 2/e - Garrett & Grisham Biochemistry 2/e - Garrett & Grisham Biochemistry 2/e - Garrett & Grisham Biochemistry 2/e - Garrett & Grisham Biochemistry 2/e - Garrett & Grisham 1.4 Properties of Biomolecules Reflect Their Fitness to the Living Condition • • • • Important numbers! van der Waals: 0.4-4.0 kJ/mole Hydrogen bonds: 12-30 kJ/mole Ionic bonds: 20 kJ/mole Hydrophobic interactions: <40 kJ/mole Biochemistry 2/e - Garrett & Grisham Biochemistry 2/e - Garrett & Grisham Two Important Points About Weak Forces • Biomolecular Recognition is Mediated by Weak Chemical Forces • Weak Forces Restrict Organisms to a Narrow Range of Environmental Conditions Biochemistry 2/e - Garrett & Grisham Biochemistry 2/e - Garrett & Grisham Biochemistry 2/e - Garrett & Grisham Biochemistry 2/e - Garrett & Grisham Biochemistry 2/e - Garrett & Grisham Organization and Structure of Cells • Prokaryotic cells – A single (plasma) membrane – no nucleus or organelles • Eukaryotic cells – much larger in size than prokaryotes – 103-104 times larger! – Nucleus plus many organelles – ER, Golgi, mitochondria, etc. Biochemistry 2/e - Garrett & Grisham Biochemistry 2/e - Garrett & Grisham Biochemistry 2/e - Garrett & Grisham Biochemistry 2/e - Garrett & Grisham