Biochemistry & Molecular Biology Yanli Yang Mar 1st ,2016 Copyright©2016 by Yang

LECTURE 1 Introduction

Biochemistry & Molecular Biology Contains only lectures Great help for BIOL2000, BIOL2001 and Gene3000

Marking: Biochemistry 60% Molecular Biology 40% Assignments 20% In-class tests 20% Exam 60%

Contact: Phone: 13358285961 E-mail: 19677159@qq.com

Course Materials Textbooks: Principles of Biochemistry,5th Edition Moran,Horton Cell and Molecular Biology, Gerald Karp, 6th Edition, John Wiley & Sons, Inc. Reference Book: 基础生物化学，郭蔼光，高教出版社 生物化学,王镜岩等,高等教育出版社

Biochemistry? Biology Agriculture Plant Science Biochemistry + Animal Science Envi. Science Chemistry Manufacturing ………

What are you going to learn? The structures, functions and interactions of cellular components such as proteins, carbohydrates, lipids, nucleic acids and other biomolecules The biochemical pathways and activities that account for the synthesis and degradation of the major macromolecules in living cells. Catalytic and regulatory strategies use by living cells.

Lecture Contents Unit I : Structure and Function  Chapter 1 Nucleic Acids Chapter 2 Proteins Chapter 3 Enzymes Chapter 4 Vitamins and Coenzymes Unit II: Metabolism Chapter 5 Biological Oxidation Chapter 6 Carbohydrate Metabolism Chapter 7 Lipid Metabolism Chapter 8 Metabolism Regulation

Lecture Contents cont’ Unit III: Information Pathways Chapter 9 Chromosome structure Chapter 10 DNA replication Chapter 11 DNA repair Chapter 12 Transcription in prokaryotes Chapter 13 Transcription in eukaryotes Chapter 14 Protein synthesis

Biochemistry is a modern science 1828, Friedrich Wöhler Inorganic Organic

Two major breakthroughs Enzymes as catalysts Nucleic acids as information-carrying molecules

The chemical elements of life 97%, C, H, O, N, P, S 3%, 23 other elements

The basic types of organic compounds commonly encountered in biochemistry

Many Important Macromolecules Are Polymers Anabolic Building block Simple sugar Amino acid Nucleotide Fatty acid Macromolecule Polysaccharide Protein (peptide) RNA or DNA Lipid Catabolic

This process joins two sugar monomers to make a double sugar molecule Linking Monomers Cells link monomers by dehydration process (removing a molecule of water) Remove H H2O Forms Remove OH This process joins two sugar monomers to make a double sugar molecule

Breaking Down Polymers Cells break down macromolecules by a process called hydrolysis (adding a molecule of water) Water added to split a double sugar molecule

Nucleic Acids Store hereditary information Contain information for making all the proteins Two types exist --- DNA & RNA

Proteins Functions as transport proteins, structural proteins, enzymes, antibodies, cell receptors. Building blocks of proteins. R Group (side chains) determines the chemical properties of each amino acids. Also determines how the protein folds and its biological function.

Proteins as Enzymes Many proteins act as biological catalysts or enzymes Enzymes control the rate of chemical reactions by weakening bonds, thus lowering the amount of activation energy needed for the reaction ——Catalysator Enzymes are reusable! Thousands of different enzymes exist in the body No not interfere with the equilibrium of reaction Active site - a cleft or groove in an enzyme that binds the substrates of a reaction The nature and arrangement of amino acids in the active site make it specific for only one type of substrate. (accepts just one enaniomer) Egg white lysozyme

Sugars Carbohydrates Basic unit is Monosaccharides. Starch, Glycogen Dietary energy Structure Storage Intercellular communications Carbohydrates most abundant organic molecule found in nature. Initially synthesized in plants from a complex series of reactions involving photosynthesis. Basic unit is monosaccharides. Monosaccharides can form larger molecules e.g. glycogen, plant starch or cellulose. Functions Store energy in the form of starch (photosynthesis in plants) or glycogen (in animals and humans). Provide energy through metabolism pathways and cycles. Supply carbon for synthesis of other compounds. Form structural components in cells and tissues. Intercellular communications

Lipids Fats, oils and steriods. Storage of energy Membrane structures Insulation (thermal blanket) Synthesis of hormones Are monocarboxylic acid contains even number C atoms Two types: saturated (C-C sb) and unsaturated (C-C db) Fatty acids are components of several lipid molecules. E,g. of lipids are triacylglycerol, steriods (cholestrol, sex hormones), fat soluble vitamins. Functions Storage of energy in the form of fat Membrane structures Insulation (thermal blanket) Synthesis of hormones

Structure of a biological membrane A lipid bilayer with associated proteins

The Cell Is the Basic Unit of Life

Prokaryotic Cells

Eukaryotic Cells

Any questions?