Chapter 5 Organic Macromolecules

Polymerization is… –the forming of large organic compounds (polymers) by the joining of smaller repeating units called monomers M M M

How does polymerization occur? By Dehydration Synthesis: the removal of a water molecule to form a new bond. HO H H2OH2O H H Short PolymerMonomer Dehydration removes a water molecule forming a new bond

How are polymers broken? HO H H2OH2O H H Short Polymer Monomer Hydrolysis adds a water molecule to break a bond by hydrolysis - literally, “Water Splitting” Add water to break bonds

4 Types of Organic Polymers 1)Carbohydrates 2)Lipids 3)Proteins 4)Nucleic Acids

Carbohydrates Formula (CH 2 O) n 2:1 ratio of H:O Carbonyl Groups Ring form in (aq) solution Important Energy Source Cellular Structures Monomer: –Monosaccharides Polymers: –Disaccharides –Polysaccharides

Monosaccharides Monosaccharides (simple sugars) –Contain 3-7 Carbons each Examples: Glucose, Galactose, Fructose Glucose

Disaccharides Disaccharides (two sugars) – joined by dehydration synthesis Examples: Sucrose, Maltose, Lactose –Maltose = Glucose + Glucose –Lactose = Glucose + Galactose Sucrose GlucoseFructose

Polysaccharides Polysaccharides (many sugars, usually thousands) Examples: Starch, Glycogen, Cellulose StarchCellulose ChloroplastStarch Glycogen Liver Cell Plant Cells Cellulose

Starch and Cellulose Structures (Plant Polysaccharides) ά – linkages (cis- formation) are easily hydrolyzed, while β - linkages (trans-formation)are not

Glycogen and Chitin (Animals Polysaccharide) Glycogen = glucose polymer –Stored in liver/muscle Chitin = structural polymer in exoskeletons

Lipids Elements: C, H, O with H:O ratio > 2:1 Hydrophobic Lipids function in: –Energy (E) storage, –forming cell membranes, –and as chemical messengers (ex. hormones) Monomers: glycerol, fatty acids, sometimes phosphate groups Polymers: –Fats (triglycerides) –Phospholipids –Steroids

Triglycerides Fats (Triglycerides) –G–Glycerol + 3 Fatty Acids –S–Saturated = No Double Bonds (solid) –U–Unsaturated = Double Bonds (liquid) OH Ester Bonds

Phospholipids Phospholipids –G–Glycerol with Phosphate Head + 2 Fatty Acid Chains –A–Amphiphilic (“Both” “lover”) Hydrophilic head Hydrophobic tail –F–Forms 2 layers in water –M–Makes up cell membranes Phosphate Glycerol Fatty Acids

Steroids OH O Testosterone HO O Estrogen AKA Sterols –L–Lipids whose Carbon Skeleton consists of 4 fused rings –I–Includes: Hormones Cholesterol Cortisol –M–Makes up cell membranes HO OH O O

Proteins (Polypeptides) Polymers of AA – 20 AA, all varied in their “R” groups – 9 essential AA can not be made by the body 50% of dry weight of organisms Varied fcns: enzymatic, structural, hormonal, transport, storage, mvmt, defense, etc. Protein function unique with 3-D shape

Proteins Protein monomers are called amino acids –Peptide Bond: Bond between 2 Amino Acids: H2OH2OH2OH2O Side Chains Backbone R Group = Amino end Carboxyl end

Protein Structure Primary Secondary Tertiary Quarternary Polypeptides fold and twist to form a specific shape to create a functional protein

Primary Structure AA sequence

Secondary Structure AA H-bonded at backbone (no interaction btwn side chains) α – Helix β - Pleated Sheats

Tertiary Structure More Complex Folding Interactions btwn side chains –H bonds –Ionic Bonding (+/-) –Hydrophobic Interactions –Disulfide Bridges

Quarternary Structure 2 or more polypeptide chains assemble Ex. Hemoglobin (4 polypeptide chains)

Functional Proteins Hi sweeties, Do you remember me? In addition to what you know. I am a substrate. I am an enzyme. I am going to try to convert you. I am now a product. I am a glucose now. I am a product, too. I am a fructose now. I am completely unchanged, and ready for some more sucrose! I am the active site. The substrate binds to me. The twisting and folding into tertiary or quarternary structures creates active sites with a specific shape that fits specific substrates that are responsible for catalyzing reactions

Factors That Affect Protein Formation pH Salinity Temperature (ex. Boiled egg) Denaturization = unraveling of protein  loss of shape and function Renaturization can occur, but not always

Nucleic Acids –Informational Polymers: Code for all of the proteins in an organism –Monomers: Nucleotides Phosphate Group Pentose 5-C Sugar –Ribose or deoxyribose Nitrogenous base –Purines (A, G) –Pyrimidines (T, C, U)

Nucleic Acids Polymers –DNA –RNA (tRNA, mRNA, rRNA) DNA directs RNA synthesis RNA directs protein synthesis

Base Pairing Rules DNA Base Pair Rules C = G A = T RNA Base Pair Rules C = G A = U