Molecules of Life

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

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

 Carbohydrates  Lipids  Proteins  Nucleic Acids

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

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

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

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

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

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

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

 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

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

 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

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

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

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

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

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

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

 Polypeptides—polymer of proteins

 Structure  Primary  Secondary  Tertiary  Quaternary

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

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

 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

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