Bài giảng Biochemistry 2/e - Chapter 1: Chemistry is the Logic of Biological Phenomena to accompany Biochemistry, 2/e

CHAPTER 1Chemistry is the Logic of Biological Phenomena to accompanyBiochemistry, 2/ebyReginald Garrett and Charles GrishamAll 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 Outline1.1 Distinctive Properties of Living Systems1.2 Biomolecules: Molecules of Life1.3 Biomolecular Hierarchy1.4 Properties of Biomolecules1.5 Organization and Structure of Cells1.6 Viruses as Cell ParasitesOn Life and Chemistry...“Living things are composed of lifeless molecules” (Albert Lehninger)“Chemistry is the logic of biological phenomena” (Garrett and Grisham)1.1 Distinctive Properties of Living SystemsOrganisms are complicated and highly organizedBiological structures serve functional purposesLiving systems are actively engaged in energy transformationsLiving systems have a remarkable capacity for self-replication1.2 Biomolecules: The Molecules of LifeH, O, C and N make up 99+% of atoms in the human body ELEMENT PERCENTAGE Oxygen 63 Hydrogen 25.2 Carbon 9.5 Nitrogen 1.41.2 Biomolecules: The Molecules of LifeWhat 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.1.2 Biomolecules: The Molecules of LifeWhat are the bond energies of covalent bonds? Bond Energy kJ/mol H-H 436 C-H 414 C-C 343 C-O 3511.3 A Biomolecular HierarchySimple Molecules are the Units for Building Complex StructuresMetabolites and MacromoleculesOrganellesMembranesThe Unit of Life is the Cell1.4 Properties of Biomolecules Reflect Their Fitness to the Living ConditionMacromolecules and Their Building Blocks Have a “Sense” or DirectionalityMacromolecules are InformationalBiomolecules Have Characteristic Three-Dimensional ArchitectureWeak Forces Maintain Biological Structure and Determine Biomolecular Interactions1.4 Properties of Biomolecules Reflect Their Fitness to the Living ConditionImportant numbers!van der Waals: 0.4-4.0 kJ/moleHydrogen bonds: 12-30 kJ/moleIonic bonds: 20 kJ/moleHydrophobic interactions: <40 kJ/moleTwo Important Points About Weak ForcesBiomolecular Recognition is Mediated by Weak Chemical ForcesWeak Forces Restrict Organisms to a Narrow Range of Environmental ConditionsOrganization and Structure of CellsProkaryotic cellsA single (plasma) membraneno nucleus or organellesEukaryotic cellsmuch larger in size than prokaryotes103-104 times larger!Nucleus plus many organellesER, Golgi, mitochondria, etc.