Building Complex Molecules That Comprise Living Things Macromolecules Building Complex Molecules That Comprise Living Things

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

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

Carbohydrates: Structure Simple Disaccharides = two sugar units Glycosidic Linkage CH2OH H HO OH O Glucose CH2OH H HO OH O HOCH2 O HOCH2 H CH2OH HO Fructose + HO H Sucrose & Water

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

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

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

Applying Your Knowledge Monosaccharide Polysaccharide Disacharide Which molecule consists of two sugar units? Which choice best describes glycogen? Which type of molecule provides the basic energy for your cells? Which type of molecule is found in milk?

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

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

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

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

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

Lipids: Structure Phospholipid—component of cell membranes Hydrophilic Polar Head Glycerol Fatty Acid Tails Hydrophilic Hydrophobic

Lipids: Structure Steroids Testosterone Linked carbon rings Used to produce Hormones Cholesterol Vitamin D2 Testosterone

Lipids: Functions Concentrated energy source Structural components of cell membranes Phospholipids Cholesterol Carotenoids capture light energy for photosynthesis Communication Steroid Hormones Metabolism Fat-soluble vitamins Insulation Protection from water Waxes Cholesterol Phospholipids

Applying Your Knowledge Polyunsaturated fatty acid Cholesterol Monounsaturated fatty acid Saturated fatty acid Which molecule is made of a series of carbon rings? Which molecule has more than one double bond? Which molecule has 2H for each internal carbon? Which molecule has one double bond?

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

The “R” Group Differs for Each Amino Acid Proteins: Structure Primary structure = chain of amino acids Amino acids have common features Carboxylic Acid Group Amino Group     See p 34 R “Alpha” Carbon The “R” Group Differs for Each Amino Acid

Proteins: Structure Forming the Protein Chain Phenylalanine Leucine Dehydration Synthesis between COOH & NH2

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

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

Protein Folding Within the Cell Proteins called chaperonins assist in proper folding of newly synthesized proteins Some 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 Carboxyl Terminus Amino Terminus

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

Found in most proteins Found in silk

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

Interactions in Tertiary Structure Covalent bonding (disulfide bridges) Hydrogen bonding Hydrophilic interactions Hydrophobic interactions (van der Waals forces) Ionic interactions (salt bridges)

Maintaining Protein Structure Denaturation 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 ions

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

Proteins: Functions Structural Component of Cells Control of Metabolic Reactions: enzymes Transport Protection and Support Movement Growth and Repair Defense Against Disease Communication/Regulation Protein Hormones Cell Receptors Energy source Protein Protein

Applying Your Knowledge Primary Secondary Tertiary Quaternary Which structure results solely from hydrogen bonding? Which structure involves an association of two or more protein chains? Which structure describes the linear sequence of amino acids? Which structure depends upon interactions between the R groups of the amino acids?

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