Chapter 4 – Carbon and Molecular Diversity

1. Chapter 4 – Carbon and Molecular Diversity

2. Outline • I. The Importance of Carbon • Organic Chemistry is the study of carbon compounds. • Carbon atoms are the most versatile building blocks of molecules. • Variation in carbon skeletons contributes to the diversity of organic molecules. • II. Functional Groups A. Functional Groups also contribute to the molecular diversity of life.

3. A. Organic Chemistry is the study of carbon compounds • Organic molecules- contain carbon • Vitalism- Belief in a life force outside the jurisdiction of chemical/physical laws • Early 19th century organic chemistry was built on this belief because chemists couldn’t make organic compounds artificially. It was believed that only living things could produce organic compounds.

4. Mechanism – belief that all natural phenomena are governed by physical and chemical laws. • Pioneers of organic chemistry started making organic molecules from inorganic. This helped shift the mainstream thinking from vitalism to mechanism. • Ex- Friedrich Wohler made urea in 1828, Hermann Kolbe made acetic acid. • Stanley Miller (1953) demonstrated the possibility that organic molecules could have been produced under chemical conditions of early Earth’s history.

5. B. Carbon atoms are the most versatile building blocks of molecules • The carbon atom has an atomic number of 6, it has 4 valence electrons • Usually completes that outer shell by sharing valence electrons in four covalent bonds. • Large complex molecules are possible and determined by their tetravalent electron configuration. This gives the complicated 3D structures their variety.

6. C. Variation in carbon skeletons contribute to diversity of organic molecules • Carbon skeletons can may vary in: • Length • Shape • Number and location of double bonds • Other elements covalently bonded to other sites

7. Hydrocarbons – molecules containing only carbon and hydrogen • Are major components of fossil fuels • Very diverse • Their framework is the basis for the large diverse organic molecules found in living organisms • Hydrocarbon chains are hydrophobic because the C-C and C-H bonds are nonpolar.

8. 1. Isomers • Compounds with the same molecular formula but with different structures so that means different properties • Structural- differ in the covalent arrangement of the atoms • Geometric- same covalent partners but differ in spatial arrangement • Enantiomers- mirror images

9. II. Functional Groups • Have specific chemical and physical characteristics • Influence the molecule they bond to • 1. Hydroxyl Group: (-OH) forms alcohols • 2. Carbonyl Group: (-CO) sugars, aldehydes, or ketones • 3. Carboxyl Group: (-COOH) carboxylic acids • 4. Amino Group: (-NH2) amines • 5. Sulfhydryl Group: (-SH) stabilize structure of protein • 6. Phosphate Group: (H3PO4) acidic, important to cellular energy storage and transfer