2. Molecules of Life

3.  Always contain carbon  Always have covalent bonds (not ionic)  Usually associated with large numbers of atoms  Commonly associated with living things

4.  Can covalently bond with as many as 4 other atoms  Can form many shapes

6.  Carbohydrates  Lipids  Proteins  Nucleic Acids

7.  Monomer—individual building unit  Polymer—many units covalently bonded

8.  Functional groups—atoms or clusters of atoms covalently bonded to organic compounds that affect the compound’s structure and fuction

9.  Mediated by enzymes (special proteins)  Fuctional-group transfer  Electron transfer  Rearrangement  Condensation  Cleavage

10.  Split OH - from one molecule  Split H + from another molecule  Bonds form at exposed sites  Water is byproduct

11.  Reverse of condensation  Split molecules  Add OH - and H + from water

12.  Monosaccharides  Single sugar unit  Soluble in water  Sweet taste  Hydroxyl group (OH - )  Used to assemble larger carbohydrates

13.  Oligosaccharide  Short chain of two or more sugar monomers  Disaccharide—2 units, simplest

14.  Polysaccharide—chain of hundreds or thousands of monomers  “Complex” carbohydrates  Starch—plant energy source  Cellulose—plant cell wall  Glycogen—animal muscle energy  Chitin—structural component of insects

15.  Greasy or oily compounds  Non-polar, hydrophobic  Energy storage, membrane structure, coatings

16.  Fatty acids—long chain of mostly C and H with a carboxyl group (-COOH) at the end  Saturated—single Carbon bonds  Unsaturated—double Carbon bonds

17.  Fat—one or more fatty acids attached to glycerol  Twice the energy of carbohydrates  Insulation

18.  Phospolipid  2 Fatty Acids + Phosphate Group + Glycerol  Main structural material of membranes

19.  Sterols  4 carbon rings, no fatty acid tails  Cholesterol, testosterone, estrogen

20.  Waxes  Long-chain fatty acids + alcohols or carbon rings  Coatings for plant parts or animal coverings

21.  Most diverse of all biological molecules  Enzymes  Cell movement  Storage & transport  Hormones  Antibodies  Structure

22.  Amino acid—monomer unit  Three groups covalently bonded to central C

23.  Polypeptides—polymer of proteins

24.  Structure  Primary  Secondary  Tertiary  Quaternary

25.  Why is structure important?  Change in shape is VERY important to function

26.  Nucleotide—monomer unit  5-carbon sugar (ribose or deoxyribose)  Nitrogen base  Phosphate group

27.  DNA—double-stranded helix, carries hereditary information  RNA—single-stranded helix, translates code to build proteins  ATP—single nucleotide, releases energy for cells to work

28.  Large number of hydrogen bonds  Nitrogen bases: Adenine, Cytosine, Guanine, Thymine (Urasil)