Chapter 2: The Chemistry of LifeSection 2.2: The Compounds of Life

Objective:3.3.10A Explain the structural and functional similarities and differences found among living things.3.3.10B Describe and explain the chemical and structural basis of living organisms

CarbonCan form 4 covalent bonds. Bonds short and strong; can form long, stable chains. Can form bonds with other carbon (C) atoms, hydrogen (H), oxygen (O), nitrogen (N), phosphorus (P) and other elements.

NO element matches carbon in forming chains of different shapes, sizes and complexity.

Organic compounds contain at least 2 C atoms (with some exceptions). All other compounds are inorganic compounds.

Sub-Objective:Define macromolecule.Identify the 4 major classes of macromolecules.

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 very large polymers.

4 Major MacromoleculesCarbohydrates

CarbohydratesInclude sugar and starchesComposed 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 CarbohydratesMonosaccharides 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 formula C6H12O6, but each has a slightly different arrangement of its atoms.

Three Types of CarbohydratesMonosaccharides simple sugars (one unit).Disaccharides 2 simple sugars bonded together.

DisaccharidesSucrose table sugar Lactose milk sugar Maltose malt sugar The above are isomers of each other. C12H22O11

Three Types of CarbohydratesMonosaccharides 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.

LipidsWaxes: * Different backbone than oils and fats.* Act as waterproofing materials for plants and animals.

LipidsPhospholipids * Composed of fatty acid chains, a glycerol backbone and a phosphate group.* Forms the structural basis of cell membranes.

LipidsSterols* Series of carbon rings.* Important role in building cells and carrying messages in the body.* Cholesterol and steroid hormones.

ProteinsPolymers 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

ProteinThe 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.

ProteinsPrincipal components of feathers, skin and muscles. Help chemical reactions to proceed (enzymes). Pump small molecules in and out of cells.

Nucleic AcidsInformation carrying molecules.DNA and RNA Assembled from nucleotides.

Nucleic AcidsNucleotides 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.

ATPTemporary energy storage in cells.Composed of nucleotides