The Structure and Function of Macromolecules
I. Polymers What is a polymer? Poly = many; mer = part. A polymer is a large molecule consisting of many smaller sub-units bonded together. What is a monomer? A monomer is a sub-unit of a polymer.
A. Making and Breaking Polymers How are covalent linkages between monomers formed in the creation of organic polymers? Condensation or dehydration synthesis reactions. Monomers are covalently linked to one another through the removal of water. Covalent bonds where electrons are shared equally are called nonpolar and where electrons are unequally shared are polar covalent bonds.
Condensation Synthesis
Hydrolysis What is a hydrolysis reaction? Polymers are broken down into monomers. Hydro = water; lysis = loosening/ Water is added and the lysis of the polymer occurs.
Hydrolysis Names of the covalent bonds Monomers use covalent bonds to form polymers. Covalent bonds have different names for each macromolecule Carbohydrates=Glycosidic linkages Proteins=peptide bonds Lipids=Ester bonds Nucleic acids=phosphodiester bonds
II. Classes of Organic Molecules: What are the four classes of organic molecules? Carbohydrates Lipids Proteins Nucleic Acids
Sugars A. Carbohydrates Contains carbon, hydrogen and oxygen Carbo = carbon, hydrate = water; carbohydrates have the molecular formula (CH 2 O) n Functions: Store energy in chemical bonds Glucose is the most common monosaccharide Glucose is produced by photosynthetic autotrophs
3. Polysaccharides Structure: Polymers of a few hundred or a few thousand monosaccharides. Functions: energy storage molecules or for structural support:
Starch is a plant storage from of energy, easily hydrolyzed to glucose units Cellulose is a fiber-like structureal material - tough and insoluble - used in plant cell walls Glycogen is a highly branched chain used by animals to store energy in muscles and the liver. Chitin is a polysaccharide used as a structural material in arthropod exoskeleton and fungal cell walls.
B. Lipids Structure: Greasy or oily nonpolar compounds Contain carbon, hydrogen and oxygen Functions: Energy storage membrane structure Protecting against desiccation (drying out). Insulating against cold. Absorbing shocks. Regulating cell activities by hormone actions.
Saturated and Unsaturated Fats Unsaturated fats : liquid at room temp one or more double bonds between carbons in the fatty acids allows for kinks in the tails most plant fats Saturated fats: have only single C-C bonds in fatty acid tails solid at room temp most animal fats
3. Phospholipids Structure: Glycerol + 2 fatty acids + phosphate group. Function: Main structural component of membranes, where they arrange in bilayers. Waxes: Lipids that serve as coatings for plant parts and as animal coverings. Sterols Component of animal cell membranes Modified to form sex hormones
Structure: C. Proteins Contain carbon, hydrogen, nitrogen and oxygen Polypeptide chains Consist of peptide bonds between 20 possible amino acid monomers Have a 3 dimensional globular shape Single chain of amino acids makes primary proteins
1. Functions of Proteins Enzymes which are catalyst and speed up the chemical reaction. Enzymes contain active site where substrate attaches. Structural materials, including keratin (the protein found in hair and nails) and collagen (the protein found in connective tissue).
antibodies that bind specifically to foreign substances. membrane transport proteins that move substances across cell membranes, and blood proteins, such as hemoglobin, that carry oxygen, iron, and other substances through the body. Contraction, such as actin and myosin fibers that interact in muscle tissue. Signaling, including hormones such as insulin that regulate sugar levels in blood.
D. Nucleic Acids Contains carbon, hydrogen, nitrogen, phosphorous and oxygen Two kinds: DNA: double stranded can self replicate makes up genes which code for proteins is passed from one generation to another RNA: single stranded functions in actual synthesis of proteins coded for by DNA is made from the DNA template molecule
DNA: Double helix 2 polynucleotide chains wound into the double helix Base pairing between chains with H bonds A - T C - G
Summary of the Organic Molecules: