The CARBON CHEMISTRY of Life

Structural Isomers Molecules with the same molecular formula but with a different arrangement of atoms are called isomers. The differences in the shape of isomers leads to a difference in their physical and chemical properties. Molecules with the same molecular formula but with a different arrangement of atoms are called isomers. The differences in the shape of isomers leads to differences in their physical and chemical properties.

For example, glucose, galactose and fructose have the same molecular formula (C6H12O6) but different structures. glucose galactose

For example, glucose, galactose and fructose have the same molecular formula (C6H12O6) but different structures. galactose fructose glucose

For example, glucose, galactose and fructose have the same molecular formula (C6H12O6) but different structures. C6H12O6 galactose fructose glucose

For example, glucose, galactose and fructose have the same molecular formula (C6H12O6) but different structures. C6H12O6 galactose fructose glucose

For example, glucose, galactose and fructose have the same molecular formula (C6H12O6) but different structures. C6H12O6 galactose fructose glucose

For example, glucose, galactose and fructose have the same molecular formula (C6H12O6) but different structures. galactose fructose glucose

In fact, glucose itself has 3 different structural isomers In fact, glucose itself has 3 different structural isomers. In a dry state, glucose has a linear structure, but when it dissolves in water, the molecule folds on itself to form one of two possible ring structures: In fact, glucose itself has 3 different structural isomers. In a dry state, glucose has a linear structure, but when it dissolves in water, the molecule folds on itself to form one of two possible ring structures: In fact, glucose itself has 3 different structural isomers. In a dry state, glucose has a linear structure, but when it dissolves in water, the molecule folds on itself to form one of two possible ring structures: In fact, glucose itself has 3 different structural isomers. In a dry state, glucose has a linear structure, but when it dissolves in water, the molecule folds on itself to form one of two possible ring structures: glucose folds to form a ring dissolved in water

β-glucose dissolved in water In fact, glucose itself has 3 different structural isomers. In a dry state, glucose has a linear structure, but when it dissolves in water, the molecule folds on itself to form one of two possible ring structures: α-glucose β-glucose or glucose α-glucose β-glucose dissolved in water

In fact, glucose itself has 3 different structural isomers In fact, glucose itself has 3 different structural isomers. In a dry state, glucose has a linear structure, but when it dissolves in water, the molecule folds on itself to form one of two possible ring structures: α-glucose glucose dissolved in water β-glucose dissolved in water

These two isomers of glucose differ only in the orientation of a single hydroxyl (-OH) group. This small structural difference leads to a large difference in their chemical properties. These two isomers of glucose differ only in the orientation of a single hydroxyl (-OH) group. This small structural difference leads to a large difference in their chemical properties. α-glucose glucose dissolved in water β-glucose dissolved in water

The starch found in mushrooms (amylopectin) is a polymer of α-glucose and can be easily digested. starch - digestible Cellulose (found in celery) is a polymer of β-glucose and cannot be digested by most animals. cellulose - not digestible

Structure = Function Isomers illustrate that the structure of a molecule determines the function of that molecule. Structure = Function

Organic Chemistry Basic building blocks of organisms are made of molecules Molecules formed by living organisms, typically contain carbon  organic compounds Has a carbon backbone with other atoms covalently bonded to it Most common are hydrogen, oxygen, nitrogen and sulfur

Carbon to carbon covalent bonds can form: ………chains …..rings …branched structures

HYDROCARBONS Molecules consisting of only carbon atoms bonded to hydrogen atoms Simplest: methane A carbon atom will always have four bonds

Functional Groups Atoms or groups of atoms covalently bonded to a carbon backbone Each group of atoms has its own definitely chemical properties The structure of the group and its electron configuration affect the function of the molecule Usually ionic or strongly polar Interact with other molecules Initiate chemical reactions to form new bonds

ethane ethanol

Methanoic Acid (HCOOH) Sugars, fats, amino acids Functional Group Family Structural Formula R=rest of molecule Example Common Locations Hydroxyl -OH Alcohol Methanol (CH3OH) Sugars, other alcohols Carbonyl -CHO at end Aldehyde Formaldehyde (CHOH) Sugars C=O in chain Ketone Acetone (CH3COCH3) Carboxyl -COOH at end Carboxylic Acid Methanoic Acid (HCOOH) Sugars, fats, amino acids Amino -NH2 at end Amines Methylamine (CH3NH2) Amino acids, proteins Phosphate -PO42- at end Organic Phosphates Phosphoric Acid (H3PO4) DNA, RNA, ATP Sulfhydryl -SH at end Thiols Butathiol (C4H9SH) Proteins

Naming Organic Molecules When trying to identify the names of organic molecules, one can observe three things to assist in the naming process. The number of carbons For 1 carbon start the name with: meth- 2: eth- 5: pent- 8: oct- 3: prop- 6: hex- 9: non- 4: but- 7: hept- 10: dec- B) The number of bonds in between carbons For single bonds name ends with: -ane For double bonds: -ene For triple bonds: -yne The functional groups If there is a Hydroxyl group to the ending add --ol Carbonyl (ketone) --one Carbonyl (aldehyde) --al Amino --amine Carboxyl --noic acid

Examples 1. CH4 *one carbon, therefore - Meth *single bonds therefore - ane Methane 2. CH3CH2OH *two carbon – Eth *single bond – ane *alcohol - ol Ethanol

Ketone propanone 3 carbons Carboxyl butanoic acid

Glycine: H2NCH2COOH carboxyl amino

Homework Read pages 25 - 28 Answer p. 28 #1, 2, 4, 12a