Nature

* Chapter 5 The Structure and Function of Macromolecules * The Molecules of Life Overview: Another level in the hierarchy of biological organization is reached when small organic molecules are joined together Atom ---> molecule ---? compound * Macromolecules Are large molecules composed of smaller molecules Are complex in their structures Figure 5.1 * Macromolecules Most macromolecules are polymers, built from monomers Four classes of life?s organic molecules are polymers Carbohydrates Proteins Nucleic acids Lipids * A polymer Is a long molecule consisting of many similar building blocks called monomers Specific monomers make up each macromolecule E.g. amino acids are the monomers for proteins * The Synthesis and Breakdown of Polymers

Organic Compounds The Structure and Function of Macromolecules Biological Molecules The study of carbon compounds, organic chemistry, focuses on any compound with carbon (organic compounds) Proteins, DNA, carbohydrates, and other molecules that distinguish living matter from inorganic material are all composed of carbon atoms bonded to each other and to atoms of other elements Carbon Atoms Carbon is building block of molecules Carbon has 4 valence electrons Can form 4 covalent bonds Tetravalence by carbon makes large, complex molecules possible Carbon Skeletons Carbon chains form the skeletons of most organic molecules The skeletons may vary in length and may be straight, branched, or arranged in closed rings. The carbon skeletons may include double bonds.