Macromolecules Building Complex Molecules That Comprise Living Things

Macromolecules: Polymers Made of Repeating Monomers Macromolecule Monomer Unit CarbohydratesSugars Lipids Fatty acids Proteins Amino acids Nucleic Acids Nucleotides

Carbohydrates: Structure SimpleSimple –Monosaccharides= one sugar unit Glucose = blood sugar All cells use glucose for energy.

Carbohydrates: Structure HOH CH 2 OH H HO H OH H HO HH O O HOCH 2 H CH 2 OH HHO HHO O H HO H OH H HO H OH H O Glucose O HOCH 2 H CH 2 OH HHO HO HHO Fructose Sucrose & Water ++ SimpleSimple –Disaccharides = two sugar units Glycosidic Linkage

Carbohydrates: Structure Complex – –Polysaccharides= many sugar units found in plant cell walls energy storage in animals energy storage in plants

Chemically- Modified Carbohydrates Sugar Phosphate Galactosamine is found in cartilage Amino Sugars Chiton forms the exoskeleton of insects Amino Sugar

Carbohydrates: Functions Energy sourceEnergy source Source of carbon skeletons for synthesis of other biological moleculesSource of carbon skeletons for synthesis of other biological molecules Structural component of cellsStructural component of cells Cell-cell communicationCell-cell communication

Eating Any Carbs Lately? Nutritionists recommend that carbohydrates be included as an important energy source in the dietNutritionists recommend that carbohydrates be included as an important energy source in the diet EmphasizeEmphasize –Complex Carbohydrates StarchStarch Fiber (cellulose)Fiber (cellulose) –Naturally-occurring simple carbohydrates Fructose from fruitFructose from fruit Lactose from milkLactose from milk Whole Grains How can I use this info?

Lipids: Structure Triglyceride— predominant form in dietTriglyceride— predominant form in diet –One molecule of glycerol –Three fatty acids

Lipids: Structure Types of Fatty AcidsTypes of Fatty Acids –Saturated – 2H per internal carbon –Unsaturated -- <2H per internal carbon  one or more double bonds Monounsaturated – one double bondMonounsaturated – one double bond Polyunsaturated – more than one double bondPolyunsaturated – more than one double bond

HH C H C H OH C H C O C C C H H H H H H H C C H H H H H H H C C O C O C C C H H H H H H H Triglyceride Triglyceride Formation C OH C C C O H H H H H H H Add 3 Fatty Acids Glycerol HOH 3 Waters C OH C C C O H H H H H H H C C C C O H H H H H H H O C H C H C H OO HH Remove These Waters C O C C C H H H H H H H C C H H H H H H H C C O C O C C C H H H H H H H Ester Linkage

Which Is a Source of Unsaturated Fatty Acids? Linseed Oil Beef Fat

Lipids: Structure Polar Head Glycerol Fatty Acid Tails HydrophobicHydrophilic Phospholipid— component of cell membranesPhospholipid— component of cell membranes

SteroidsSteroids –Linked carbon rings –Used to produce HormonesHormones CholesterolCholesterol Vitamin D 2Vitamin D 2 Lipids: Structure Testosterone

Lipids: Functions Concentrated energy sourceConcentrated energy source Structural components of cell membranesStructural components of cell membranes –Phospholipids –Cholesterol Carotenoids capture light energy for photosynthesisCarotenoids capture light energy for photosynthesis CommunicationCommunication –Steroid Hormones MetabolismMetabolism –Fat-soluble vitamins InsulationInsulation Protection from waterProtection from water –Waxes Cholesterol Phospholipids

High Fat, Low Fat, No Fat… Limit fats to < 30% of caloriesLimit fats to < 30% of calories Limit saturated fats to < 10% of caloriesLimit saturated fats to < 10% of calories Limit cholesterol to 300 mg/dayLimit cholesterol to 300 mg/day Avoid “trans” fatty acids in partially hydrogenated productsAvoid “trans” fatty acids in partially hydrogenated products EmphasizeEmphasize –Unsaturated fatty acids from vegetables, fish, legumes, and nuts –Oils: mono- or polyunsaturated How can I use this info?

Proteins: Structure Amino Group Amino Group The “R” Group Differs for Each Amino Acid Carboxylic Acid Group “Alpha” Carbon R Primary structure = chain of amino acidsPrimary structure = chain of amino acids –Amino acids have common features

Proteins: Structure Forming the Protein Chain Dehydration Synthesis between COOH & NH 2 Phenylalanine Leucine

Proteins: Structure Forming the Protein Chain WaterWater Peptide Bond Phenylalanine-Leucine Dipeptide

Four Levels of Protein Structure Primary (Sequence) Secondary (Coiling by Hydrogen Bonding) Tertiary (Folding by R-group interactions) Quaternary (Two or more chains associating)

Protein Folding Within the Cell Proteins called chaperonins assist in proper folding of newly synthesized proteinsProteins called chaperonins assist in proper folding of newly synthesized proteins Some chaperonins “trap” proteins in a molecular cage to prevent interference in the folding processSome chaperonins “trap” proteins in a molecular cage to prevent interference in the folding process

Four Levels of Protein Structure Primary Structure = sequence of amino acids in chain Amino Terminus Carboxyl Terminus

Four Levels of Protein Structure Secondary StructureSecondary Structure Folded structure due to hydrogen bonds between the amino and acid groups of amino acids Folded structure due to hydrogen bonds between the amino and acid groups of amino acids C O N H C O N H C O N H C O N H or

Found in most proteins Found in silk

Four Levels of Protein Structure Tertiary Structure:Tertiary Structure: Three dimensional folded structure due to attractions and repulsions between R groups Three dimensional folded structure due to attractions and repulsions between R groups

Interactions in Tertiary Structure Hydrogen Bonding van der Waals forces Disulfide Bridge (covalent bond) Hydrophobic Effect Ionic Bonding

Maintaining Protein Structure Denaturation disrupts tertiary and secondary structure and is not usually reversibleDenaturation disrupts tertiary and secondary structure and is not usually reversible Denaturation can be caused by heat, pH changes and other chemicals such as salts or charged ionsDenaturation can be caused by heat, pH changes and other chemicals such as salts or charged ions

Four Levels of Protein Structure Quaternary Structure:Quaternary Structure: Association of two or more protein chains Association of two or more protein chains eg. Hemoglobin is composed of 4 protein chains eg. Hemoglobin is composed of 4 protein chains 2 are called alpha hemoglobin 2 are called alpha hemoglobin 2 are called beta hemoglobin 2 are called beta hemoglobin

Proteins: Functions Structural Component of CellsStructural Component of Cells Control of Metabolic Reactions: enzymesControl of Metabolic Reactions: enzymes TransportTransport Protection and SupportProtection and Support MovementMovement Growth and RepairGrowth and Repair Defense Against DiseaseDefense Against Disease Communication/RegulationCommunication/Regulation –Protein Hormones –Cell Receptors Energy sourceEnergy source Protein

For the Remaining Calories… Protein requirements are based on body size and needs for growthProtein requirements are based on body size and needs for growth 8 essential amino acids obtained from8 essential amino acids obtained from –Lean sources of animal protein –Complementary plant proteins Beans + GrainsBeans + Grains Beans + SeedsBeans + Seeds How can I use this info?