CARBON AND THE MOLECULAR DIVERSITY OF LIFE Chapter 4 I. The Importance of Carbon

–Organic compounds can range from simple molecules, such as CO 2 or CH 4, to complex molecules, like proteins. –The % of the major elements of life (C, H, O, N, S, and P) are quite uniform from one organism to another. A. ___________ chemistry is the study of carbon compounds

1. The __________________ of carbon makes large, complex molecules possible. 2.Carbon forms single, double and triple ___________ bonds. 3.Carbon bonds to other carbon atoms forming long, stable ___________ chains. ___________ form easily. The valences of carbon and its partners can be viewed as the building code that governs the architecture of organic molecules. B. Carbon atoms are the most ________ building blocks of molecules.

C. ____________ are compounds that have the same molecular formula but different structures and therefore different chemical properties. –1. __________ isomers are molecules that have the same molecular formula but differ in the arrangement of atoms in general. –Butane and isobutane have the same molecular formula C 4 H 10, but butane has a straight skeleton and isobutane has a branched skeleton.

–2. __________ isomers are compounds with the same covalent partnerships that differ in their spatial arrangement around a carbon-carbon double bond. –The double bond does not allow atoms to rotate freely around the bond axis.

–3.________________ are molecules that are mirror images of each other. –____________ are possible if there are four different atoms or groups of atoms bonded to a carbon. –They are like left-handed and right-handed versions of each other. –Usually one is biologically active, the other inactive. –Shown are two amino acids. Biological systems use only left-handed amino acids.

II.Functional Groups

1. The components of organic molecules that are usually involved in chemical reactions are called _________ groups. 2.___________ groups are attachments that replace hydrogens bonded to the carbon skeleton of the hydrocarbon. Each functional group behaves consistently from one organic molecule to another. The number and arrangement of functional groups help give each molecule its unique properties. A. __________ groups contribute to the molecular diversity of life

There are ______ functional groups that are most important to the chemistry of life. All are _______ and increase the ________ of organic compounds in water. B. Types of Functional Groups

1. In a _________ group (-OH), a hydrogen atom forms a polar covalent bond with an oxygen atom, which forms a polar covalent bond to the carbon skeleton. – The polar covalent bonds of hydroxyl groups improve the solubility of organic molecules. –a. Organic compounds with hydroxyl groups are ________ and their names typically end in -ol.

3. A ________ group (C=O) is an oxygen atom joined to the carbon skeleton by a double bond. –a. If the carbonyl group is on the end of the skeleton, it’s an _________. –b. If not, then the compound is a ___________.

4. A ________ group (-COOH) is a carbon atom with a double bond to an oxygen atom and a single bond to a hydroxyl group. –a. Compounds with _________ groups are _________ acids.

5. An __________ group (-NH 2 ) is a nitrogen atom attached to two hydrogen atoms and the carbon skeleton. –a. Organic compounds with amino groups are _______. –b. The _______ group acts as a base. –c. Amino acids, the building blocks of proteins, have amino and carboxyl groups.

6. A _________ group (-SH) is a sulfur atom bonded to a hydrogen atom and to the backbone. –This group resembles a hydroxyl group in shape. –a. Organic molecules with _______ groups are _____. –b. ____________ groups help stabilize the structure of proteins by forming disulfide bridges with covalent bonding.

7. A __________ group (-OPO 3 2- ) is a phosphorus bound to four oxygen atoms a. _______ groups are negatively charged anions. b. Some transfer energy between organic molecules. (ATP ADP + P)