Carbon and the Molecular Diversity of Life

Transcription

1 arbon and the Molecular Diversity of Life 1

2 arbon hemistry arbon is the Backbone of Biological Molecules (macromolecules) All living organisms Are made up of chemicals based mostly on the element carbon 2

3 arbon hemistry Organic chemistry is the study of carbon compounds arbon atoms can form diverse molecules by bonding to four other atoms arbon compounds range from simple molecules to complex ones arbon has four valence electrons and may form single, double, triple, or quadruple bonds 3

4 The bonding versatility of carbon allows it to form many diverse molecules, including carbon skeletons Name and omments Molecular Formula Structural Formula Ball-and- Stick Model Space- Filling Model (a) Methane 4 (b) Ethane 2 6 (c) Ethene (ethylene) 2 4 4

5 The electron configuration of carbon gives it covalent compatibility with many different elements ydrogen Oxygen Nitrogen arbon (valence = 1) (valence = 2) (valence = 3) (valence = 4) O N 5

6 arbon may bond to itself forming carbon chains arbon chains form the skeletons of most organic molecules arbon chains vary in length and shape (a) Length (b) Branching (c) Double bonds (d) Rings Ethane Propane Butane isobutane 1-Butene 2-Butene yclohexane Benzene 6

7 ydrocarbons ydrocarbons are molecules consisting of only carbon and hydrogen ydrocarbons Are found in many of a cell s organic molecules Fat droplets (stained red) (a) A fat molecule 100 µm (b) Mammalian adipose cells 7

8 Isomers Isomers are molecules with the same molecular formula but different structures and properties Three types of isomers are Structural Geometric Enantiomers (a) Structural isomers (b) Geometric isomers X X O 2 X O 2 X (c) Enantiomers N 2 N

9 Enantiomers Are important in the pharmaceutical industry L-Dopa (effective against Parkinson s disease) D-Dopa (biologically inactive) 9

10 Functional Groups Functional groups are the parts of molecules involved in chemical reactions They Are the chemically reactive groups of atoms within an organic molecule Give organic molecules distinctive chemical properties Female lion Estradiol O 3 O 3 O 3 O Testosterone Male lion 10

11 Six functional groups are important in the chemistry of life ydroxyl arbonyl arboxyl Amino Sulfhydryl Phosphate 11

12 Some important functional groups of organic compounds FUNTIONAL GROUP YDROXYL ARBONYL ARBOXYL O O O (may be written O ) O STRUTURE In a hydroxyl group ( O), a hydrogen atom is bonded to an oxygen atom, which in turn is bonded to the carbon skeleton of the organic molecule. (Do not confuse this functional group with the hydroxide ion, O.) The carbonyl group ( > O) consists of a carbon atom joined to an oxygen atom by a double bond. When an oxygen atom is double-bonded to a carbon atom that is also bonded to a hydroxyl group, the entire assembly of atoms is called a carboxyl group ( OO). 12

13 Some important functional groups of organic compounds NAME OF OMPOUNDS EXAMPLE Alcohols (their specific names usually end in -ol) O Ethanol, the alcohol present in alcoholic beverages Ketones if the carbonyl group arboxylic acids, or organic is within a carbon skeleton acids Aldehydes if the carbonyl group is at the end of the carbon skeleton O O O Acetic acid, which gives vinegar Acetone, the simplest ketone its sour tatste O Propanal, an aldehyde 13

14 Some important functional groups of organic compounds AMINO SULFYDRYL POSPATE N S (may be written S ) O O P O O The amino group ( N 2 ) consists of a nitrogen atom bonded to two hydrogen atoms and to the carbon skeleton. The sulfhydryl group consists of a sulfur atom bonded to an atom of hydrogen; resembles a hydroxyl group in shape. In a phosphate group, a phosphorus atom is bonded to four oxygen atoms; one oxygen is bonded to the carbon skeleton; two oxygens carry negative charges; abbreviated P. The phosphate group ( OPO 3 2 ) is an ionized form of a phosphoric acid group ( OPO 3 2 ; note the two hydrogens). 14