1. Carbon CompoundsIsomers Monkemeier Honors Biology

2. Carbon Skeletons • The framework of biological molecules consists predominately of carbon atoms bonded to other carbon atoms or atoms of oxygen, hydrogen, nitrogen or sulfur. • Carbon skeletons form the backbone of biological molecules • Carbon skeletons occur in chains, branched chains or rings.

3. Four Major Types of Biological Molecules and Carbon Skeletons! • The four major types of biological molecules: carbohydrates, lipids, nucleic acids, and proteins. • Carbon chains often contain hydrogen. The C-C and C- H bonds are nonpolar since carbon and hydrogen have similar electronegativities.

4. Functional Groups • Functional Groups are specific groups of atoms (that are covalently bonded together) that have definite chemical properties that they retain no matter where they occur. • Functional Groups attached to a “carbon – chain” molecule provide that molecule with their definite chemical properties!

5. Functional Groups

6. Carbon Skeletons and Isomers! • Isomers are compounds with the same chemical formula but different structural arrangements.

7. Structural Isomers • When differences exist in in the actual structure of the carbon skeleton the compounds are structural isomers.

8. Sterioisomers • These molecules have the same carbon skeleton but differ in how the groups attached to this skeleton are arranged.

9. Enantiomers • A subcategory of sterioisomers that are mirror images of each other. • Chiral molecules are mirror images of each other. • Chiral molecules are characterized by their effect on polarized light and chiral molecules rotate to the left or right.

10. Levorotatory rotates the molecule to the left and is designated L Dextrorotatory rotates the molecule to the right and is designated D. Chiral Molecules

11. Chiral Molecules and Living Systems • Living systems tend to produce only a single enantiomer of the tow possible forms (L or D); for example, in most organisms: D – Sugars L – amino Acids

12. HOW? • How do living systems build huge polymers like starch or enzymes? • Instead of building them one atom at a time, they build them one monomer at a time. • Monomers are molecules that act as subunits that when put together form polymers (large macromolecules).

13. Monomers to Polymers

14. Monomers to Polymers

15. Dehydration Synthesis: Monomers to Polymers

16. Polymers back to Monomers: Hydrolysis

17. The Four Major Categories • Carbohydrates, Lipids, Proteins and nucleic acids are all built and broken down using the SAME TWO REACTIONS. • Dehydration Synthesis (aka condensation) forms bonds between monomers. • Hydrolysis (sometimes aka decomposition) breaks the bonds between monomers • In both reactions: DO NOT FORGET THE ROLE of WATER!

18. NEXT TIME! • The four major categories of macromolecules! • WE LOVE AP!