Chapter 2: The Chemistry of Life Section 2.2: The Compounds of Life
Macromolecules: • Monomers, meaning single units, are small molecules. • Polymers, meaning many units, are assembled by combining monomers to form large molecules. • Macromolecules, meaning giant molecules, are verylarge polymers.
4 Major Macromolecules • Carbohydrates
Carbohydrates • Include sugar and starches • Composed of C, H, and O. • Generally contain 2 H atoms for every O atom. • Short term storage of energy and structural components of some cells.
Three Types of Carbohydrates • Monosaccharides –simple sugars (one unit).
Monosaccharides • Lactose - found in milk. • Fructose – found in fruit. • Glucose – found in the cells of every organism. • They are isomers - All have the same formulaC6H12O6, but each has a slightly different arrangement of its atoms.
Three Types of Carbohydrates • Monosaccharides –simple sugars (one unit). • Disaccharides – 2 simple sugars bonded together.
Disaccharides • Sucrose – table sugar • Lactose – milk sugar • Maltose – malt sugar • The above are isomers of each other. C12H22O11
Three Types of Carbohydrates • Monosaccharides –simple sugars (one unit). • Disaccharides – 2 simple sugars* bonded together. • Polysaccharides - many monosaccharides bonded together.
Polysaccharide • Starch – storage form of energy for plants. • Glycogen – storage form of energy for animals. • Cellulose – structural component of plant cells. • Chitin – structural component of exoskeletons and fungi.
Lipids • Made from C, O and H. • Waxy, fatty or oily compounds. • Long-term storage of energy. • Oils and fats: * Composed of fatty acid chains and a glycerol backbone. * Act as insulators and cushions.
Lipids • Waxes: * Different backbone than oils and fats. * Act as waterproofing materials for plants and animals.
Lipids • Phospholipids * Composed of fatty acid chains, a glycerol backbone and a phosphate group. * Forms the structural basis of cell membranes.
Lipids • Sterols * Series of carbon rings. * Important role in building cells and carrying messages in the body. * Cholesterol and steroid hormones.
Proteins • Polymers of amino acids (20 common amino acids). • Amino acids are composed of: * Central carbon atom * Hydrogen atom * Amino group (-NH2) * Carboxyl group (-COOH) * An R group
Protein • The R group is what makes each amino acid different. • Amino acids join between the amino and carboxyl groups to form a peptide bond. • Chain of amino acids = polypeptide.
Proteins • Principal components of feathers, skin and muscles. • Help chemical reactions to proceed (enzymes). • Pump small molecules in and out of cells.
Nucleic Acids • Information carrying molecules. • DNA and RNA • Assembled from nucleotides.
Nucleic Acids • Nucleotides consist of: * Phosphate group * Nitrogen base * 5-C sugar either deoxyribose (DNA) or ribose (RNA). * 4 different nucleotides in both DNA and RNA. * Arrangement of the nucleotides determines the information that the nucleic acid contains.
ATP • Temporary energy storage in cells. • Composed of nucleotides