Organic Molecules and Biological Molecules

Basic Organic Chemistry

I. The importance of Carbon (C)

            A.  Living matter

            B. Organic chemistry is the study of carbon compounds

            C. Carbon atoms are the most versatile building blocks of molecules

            D. Variation in carbon skeletons contributes to the diversity of organic molecules

II. Functional groups

            A. Functional groups → components of organic molecules most often involved in chemical

            reactions

            B. Six functional groups most important to organic chemistry

                        1. Hydroxyl → H bonded to an oxygen, which is bonded to carbon skeleton (-OH)

                        2. Carbonyl → consists of an oxygen atom double-bonded to a carbon (C=O)

                        3. Carboxyl → When an O is double-bonded to a C that is also bonded to –OH (-COOH)

                        4. Amino → Nitrogen bonded to two hydrogen atoms and to carbon skeleton (-NH₂)

                        5. Sulfhydryl → Sulfur bonded to a carbon of the C skeleton, along with a hydrogen (-SH)

                        6. Phosphate → anion formed by dissociation of inorganic acid, phosphoric acid (H₃PO₄)

The Structure and Function of Macromolecules

I. Carbon molecules along with the functional groups bond to form a wide variety of molecules

            A. Four basic types of macromolecules important to life

                        1. Carbohydrates → fuel and building material

                        2. Lipids → diverse hydrophobic molecules

                        3. Proteins → many structures, many functions

                        4. Nucleic acids → informational polymers

            B. Polymer principles

                        1. Polymers → long molecules consisting of many subunits that typically are similar

                        but not always

                        2. Monomers → the repeating units that serve as the building blocks of a polymer

III. Carbohydrates

            A. Two major biochemical roles

                        1. source of energy

                        2. Serve as carbon skeletons to form other biological molecules → amino acids and fatty acids

            B. Include sugars and their polymers

                        1. Most names for sugars end in -ose

                        2. Monosaccharides (Mono = one + saccharide = sugar)

                        3. Disaccharides → double sugars

                        4. Polysaccharides → macromolecules

IV. Proteins

            A. Most diverse macromolecules in terms of form and function

                        1. Structural (support)

                        2. Transport

                        3. Hormonal

                        4. Defense → antibodies combat bacteria and viruses

                        5. Metabolic → enzymes needed for speeding up chemical reactions

            B. All are constructed from the same set of monomers (20 amino acids)

                        1. Polypeptides → polymers of amino acids connected in specific sequence

                        2. Amino acids

                        3. Amino acids Linked by peptide bonds → polypeptide chains

            C. Four levels of protein structure → unique 3-D shape

                        Primary structure → sequence of amino acids

                        Secondary structure → Folding or coiling of chain

                        Tertiary structure → bending of chain due to interactions of R groups

                        Quaternary structure → linking of 2 or more chains

            D. Denaturation of proteins

V. Nucleic Acids → large molecules containing genetic information

            A. Two types

                        1. DNA (deoxyribonucleic acid) → provides directions for its own replication

                        2. RNA (Ribonucleic acid) → catalytic in some reactions

            B. Monomers → nucleotides

VI. Lipids → diverse hydrophobic molecules

            A. Only macromolecule to not consist of monomeric units

            B. Hydrophobic due to molecular structure

            C. Includes

                        1. Waxes

                        2. Steroids → cholesterol is important steroid for animals

                        3. Phospholipids → structural role in cell membranes

                        4. Fats