The Molecules of Life Chapter 5, SectionS 1-4

Living things are composed of ORGANIC molecules which contain the element CARBON (INORGANIC compounds do not!) WHY CARBON? Carbon has _____ valence electrons and can easily bond with other atoms (including other carbon atoms) to make large, complex molecules in many shapes… 4

MONOMERS AND POLYMERS Most complex macromolecules are POLYMERS which are made up of smaller units called MONOMERS Polymers are built through a DEHYDRATION reaction where a water molecule is released Polymer bonds are broken when water is ADDED in a HYDROLYSIS reaction

CARBOHYDRATES (CH2O)x Sugars and Starches Store chemical ENERGY and have some structural purposes Variable in Size SMALL MONOMER Monosaccharide Simple Sugars EX: glucose, fructose, galactose Disaccharide Glucose + Fructose = Sucrose LARGE POLYMER Polysaccharide Many glucose =starch or glycogen, Cellulose

CARBOHYDRATES HYDROPHILIC molecules (Hydroxyl Group attracts water) However, POLYSACCHARIDES do NOT dissolve in water because of their size

LIPIDS Contain mostly Carbon and Hydrogen (some Oxygen) Fats, Oils, Waxes, and Steroids HYDROPHOBIC molecules formed from a Glycerol molecule and Fatty Acid Chains (Avoid Water (Don’t Mix)- Nonpolar)

LIPIDS Store ENERGY and are a structural component of biological MEMBRANES Saturated Fats (solid at room temp): All carbon atoms single bond Unsaturated Fats (oils): One or more double-bonded carbon atoms Steroids (4 fused rings): Circulate as chemical signals (hormones); Cholesterol (Good-HDL/Bad-LDL)

NUCLEIC ACIDS Contain Carbon, Hydrogen, Oxygen, Nitrogen, and Phosphorous Molecules of INHERITANCE (DNA and RNA) Assembled from monomers called NUCLEOTIDES

PROTEINS Contain Carbon, Hydrogen, Oxygen, and Nitrogen Made of monomers called AMINO ACIDS (20 different a.a.) Amino Acids are joined by peptide bonds, therefore another name for a protein is POLYPEPTIDE There are 4 levels of structural organization

PROTEINS Proteins are very diverse and have different functions: Aid in chemical reactions (enzymes) Help fight disease (antibodies) Build bone and muscle tissue Help transport substances in/out of cell Help regulate cell processes