BIO189 - CH.3

LECTURE LEARNING OBJECTIVES

• Valence of carbon: tetravalent, forms tetrahedral structures with four covalent bonds.

• Identify functional groups: hydroxyl, carbonyl, carboxyl, amino, sulfhydryl, phosphate, methyl.

• Define isomer and describe types: structural isomers, cis-trans isomers, enantiomers.

• Define monomer and polymer.

• Describe dehydration and hydrolysis reactions: reactants and products.

• Four classes of biological macromolecules: subunits, polymers, linkage types, and functions.

FUNCTIONAL GROUPS

• Affect molecular function through chemical reactions.

• Characteristic involvement in reactions.

MACROMOLECULES

• Polymers synthesized via dehydration (loss of water), broken down by hydrolysis (addition of water).

CARBOHYDRATES

• Simple sugars: (CH2O)n; differentiations: aldoses vs ketoses.

• Disaccharides: formed by glycosidic linkages from two monosaccharides.

• Polysaccharides: storage (starch, glycogen) and structural (cellulose, chitin).

LIPIDS

• Diverse group, not true polymers, hydrophobic nature.

• Types include fats (triglycerides), phospholipids, and steroids.

PROTEINS

• Comprised of amino acids through peptide bonds.

• Levels of structure: primary, secondary, tertiary, quaternary.

• Key functions include catalysis (enzymes) and structural roles.

NUCLEIC ACIDS

• Composed of nucleotides: sugar, nitrogenous base, phosphate group.

• Functions: genetic information storage and transfer (DNA to RNA to proteins).