Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Bell Ringer Identify the 4 major macromolecules of life.
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Chapter 3 The Molecules of Life
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Cells make a huge number of large molecules from a small set of molecules 4 main classes of biological macromolecules: 1. Carbohydrates 2. Lipids 3. Proteins 4. Nucleic acids
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings How are large molecules made? Large molecules are made by joining smaller organic monomers into chains called polymers Monomers are linked by dehydration reactions (a water molecule is removed) Polymers are broken down to monomers by hydrolysis (a water molecule is added)
Short polymerUnlinked monomer Dehydration reaction Longer polymer
Hydrolysis
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings CARBOHYDRATES Monosaccharides (single sugars) are carbohydrate monomers Main fuel molecules for cellular work Manufacture other organic molecules
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings CARBOHYDRATE POLYMERS 2 monosaccharides join to form disaccharides Polysaccharides are long chains of sugar units Storage molecules – Starch in plants – Glycogen in animals Structural compounds – Cellulose in plants
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings LIPIDS Fats (triglycerides) are lipids that are mostly energy-storage molecules Consist of carbon, hydrogen and oxygen – Linked by nonpolar covalent bonds – Hydrophobic (water-fearing)
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings OTHER TYPES OF LIPIDS Phospholipids – Major component of cell membranes Waxes – Form waterproof coatings Steroids - Male & female sex hormones
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings PROTEINS Proteins are essential to the structures and activities of life Constructed from amino acid monomers linked by peptide bonds The seven major classes of proteins are 1. Structural: hair, cell cytoskeleton 2. Contractile: producers of movement in muscle and other cells
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 3. Storage: sources of amino acids, such as egg white 4. Defense: antibodies 5. Transport: carriers of molecules 6. Signaling: hormones, membrane proteins 7. Enzymes: regulators of the speed biochemical reactions
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings NUCLEIC ACIDS Nucleic acids are information-rich polymers of nucleotides There are two types of nucleic acids-DNA and RNA