1. Organic Molecules Part 2 Lipids and Nucleic Acids

2. Objectives Relate the structure of lipids to their function. List two essential functions of nucleic acids.

3. Lipids Lipids are large, non-polar organic molecules. They do not dissolve in water. Store energy efficiently. Large number of Carbon- hydrogen bonds (store more energy than Carbon-oxygen bonds)

4. Lipid Monomer Fatty Acids Unbranched carbon chains that make up most fatty acids. One end is a straight carbon chain (12-28 C) the other is a carboxyl group (-COOH) Carboxyl end is polar, and "water loving" - hydrophilic Hydrocarbon end is non-polar, and "water fearing" - hydrophobic

5. Saturated Fatty Acids Each Carbon atom is covalently bonded to 4 atoms. Carbon atoms are "full" or saturated.

6. Unsaturated Fatty Acids Carbon atoms are not bonded to the maximum number of atoms. Double bonds within the Carbon chain.

7. Lipid Polymers Divided into 3 categories based on their structure. Three classes contain fatty acids: Triglycerides, phospholipids, and waxes.

8. Triglycerides Composed of three fatty acid molecules joined to one molecule of the alcohol glycerol. Saturated -high melting points, solid at room temperature Shortening and animal fats Unsaturated -liquid at room temperature Found in plant seeds and fruits

9. Phospholipids Two fatty acids joined to a molecule of glycerol Makes up cellular (plasma) membrane (Lipid Bilayer) Creates a barrier between inside and outside of cell.

10. Wax A type of structural lipid. A long fatty acid chain joined to a long alcohol chain. Highly waterproof. Forms a protective coating on plants. Protective layers in animals (earwax, beeswax, spermaceti, lanolin)

11. Steroids Not composed of fatty acids. Made of 4 Carbon rings with various functional groups. Many animal hormones are steroid compounds. Testosterone Cholesterol

12. Nucleic Acids Very large and complex organic molecules Store important genetic information. Information can be passed from parent to offspring DNA and RNA

13. Nucleic Acid Monomers Nucleotides Made of three parts Phosphate group Five-Carbon sugar Nitrogen- containing base

14. DNA Deoxyribonucleic Acid Stores information in the nucleus of the cell Sugar is deoxyribose Double helix (two strands)

15. RNA Ribonucleic Acid Carries information out of the nucleus to make protein Sugar is ribose Single strand