OBJECTIVES
1.    To identify the four types of macromolecules that compose living organisms.
2.    To describe the chemical structures of each of the macromolecules, including lipids, carbohydrates, proteins and nucleic acids, and their components.

LECTURE ON MACROMOLECULES
I.Macromolecules
1.Molecules are composed of basic, single units called monomers to numerous units called polymers, or macromolecules
2.reaction is carried out with energy, union results in condensation Rx or dehydration Rx

3.four classes of macromolecules
   A. lipids - fatty acids or polymers of fat; generally are not soluble in water, referred to as hydrophobic effect
       1.triglycerides
             b.composed of three fatty acids and glycerol
             c.function for energy storage in adipose tissue
        2.phospholipids
            a. composed of two fatty acids, phosphorus head, since have both hydrophbic and hydrophilic sections, molecule is  amphiphatic
            b. function in biological membranes
            c. phosphorus is polar, found on the outer surface of bilipid membranes
            d. functions to form cellular, nuclear and organelle membranes
        3. cholesterol forms steriod based hormones and vitamins
           a. molecule that can be converted to many hormones within the body, vitamin D, estrogen and testosterone
        4. terpenes form pigmnents found in cells, as well as maintaining structural roles

B.   carbohydrates - monosaccarides; based on chemical formula CH₂O
      1.monosaccarides are simple sugars such as glucose, and fructose
      2.disaccharides are composed of covalently linked monosaccarides
      3.polysaccarides are complex molecules, starch, cellulose
      4.functions as source of energy, cellular support

C.   proteins - amino acids
        1. composed of twenty amino acids , based on the R' or residue group
        2.union results from dehydration (or condensation) reaction

            a. R' may be hydrophilic (water loving) or hydrophobic (water hating)
                1. C, H are hydrophobic
                2. O, N are hydrophilic
                3 . Types of proteins
         3.    Types of Proteins
            a. Structural proteins form structural units of body, muscle, hair, nails, parts of cell membrane
            b. Regulatory proteins act to control the expression of homeotic genes

    4. Arrangement of Proteins - proteins are arranged on five levels
           a. .primary - sequence of amino acids
           b. secondary - regular, repeated patterns of coiling due to alpha helix or beta sheet
               1.alpha helix is R-handed coil found in keratin (hair, nails,claws) held by H-bonds
               2.beta sheet are long sheets with hairpin turns; protein chains bound by H-bonds, silk
               3.triple helix is twisted into a cable, held together by H-bonds, (collagen, tendon)

                 1. proteins held together by sulphide bonds, such as antibodies

D.   Nucleic Acids - nucleotides
       1.Deoxyribonucleic acid (DNA)
          a. composed of:
              1. deoxyribose (pentose) sugar
              2.  phosphate group
              3.  nitrogenous bases
                    a.   adenine (purine)
                    b.   guanine (purine)
                    c.   cytosine (pyrimidine)
                    d.   thymine (pyrimidine)
         b.  functions
              1. cell replication through mitosis and meiosis
              2. protein synthesis for growth, repair of soma
         c.   monomer is nucleotide

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