BIOL 1441 1st Edition Lecture 7 Outline of Last Lecture I. 4 main classes of moleculesII. MacromoleculesIII. Carbohydrates a. Monosaccharides b. DisaccharidesOutline of Current Lecture I. PolysaccharidesII. Lipidsa. Fatsb. Phospholipidsc. SteroidsIII. ProteinsCurrent LectureI. Polysaccharides- macromoleculesa. Polymers of monosaccharides (monomers)i. Hundreds - thousands monomersii. Storage roles-energy storage (quick energy)iii. Structural roles1. Bonds between monomers determine whether storage or structuralb. The structure and function of a polysaccharide are determined by:i. Sugar monomers ii. Positions of glycosidic linkagesThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.c. Storage Polysaccharidesi. Starch- storage polysaccharide of plants1. Consists entirely of glucose monomers2. Granules within chloroplasts & other plastids 3. Stored glucose- major cellular fuel (energy)4. Hydrolyze starch- potatoes, wheat, corn5. 1® 4 linkage – helical shapeii. Glycogen- storage polysaccharide in animals1. Mainly in liver & muscle cells2. Hydrolyze glycogen sugar demand increases a. Cannot sustain you for long (1 day), replenish with foodiii. Cellulose- major structural component of plant cell walls1. Abundant organic compound on earth2. Polymer of glucose, different glycosidic linkages 3. Difference based on 2 ring structures of glucose: alpha (a) & beta (b)iv. Structural Polysaccharides- plants1. Starch- a-glucose helical shape2. Cellulose- b-glucose straighta. H(+) on one strand H-bond with OH(-) on other strandsb. Parallel cellulose molecules grouped into microfibrils, form strong building materials for plants3. Enzymes digest starch by hydrolyzing a-linkages can’t hydrolyze b-linkages in cellulose4. Cellulose passes through the digestive tract as insoluble fibera. Abrade the wall, stimulating mucus secretionb. Aids in the smooth passage of waste5. Some microbes possess enzymes digest cellulosea. Cows harbor bacteria rumen, hydrolyze hay & grassb. Termites microbes to digest woodc. Symbiotic relationshipsv. Structural Polysaccharides- animals1. Chitin- exoskeleton of arthropods & cell walls of many fungi2. Chitin can be used as surgical threadII. Lipids: do not form polymersi. Hydrophobic- no affinity for waterii. Consist mostly of hydrocarbons iii. Nonpolar covalent bondsiv. Some polar regionsv. Most biologically important lipids:1. Fats2. Phospholipids3. Steroidsb. Fatsi. Not polymers, but are large molecules1. Assembled from smaller molecules2. Dehydration reactionsii. Constructed from 2 types of smaller molecules:1. Glycerol (hydroxyl group)2. Fatty acidsiii. 3 fatty acids join to glycerol by an ester linkage, creating a triacylglycerol (triglyceride)1. Ester linkage- bond between hydroxyl group & carboxyl group2. Triglyceride- 3 fatty acids3. Fat molecule= glycerol + 3 fatty acidsiv. Fatty Acids1. Vary in length (number of carbons) & number and locations of double bonds2. Saturated fatty acids- maximum number of hydrogen atoms possible & no double bonds3. Unsaturated fatty acids- 1 or more double bonds4. Major function of fats- energy storage5. Look in hydrocarbon tail for double bondsv. Saturated Fats1. Fats made from saturated fatty acids2. Most animal fats are saturated3. Solid at room temperature4. Cardiovascular disease- plaque depositsvi. Unsaturated Fats1. Fats made from unsaturated fatty2. Plant & fish fats usually unsaturated3. “Healthy fats”4. Liquid at room temperature- oilsa. Cant be solids b/c double bonds5. Double bonds- removal of hydrogen atom6. Cis double bond- kinka. Most common7. Partially Hydrogenated…8. Take unsaturated fat and remove double bonds9. Add hydrogens- hydrogenatea. Peanut butter, margarine- prevents lipids from separating outvii. Trans fats1. Greater health concern than natural saturated fats2. Not found in nature so body doesn’t recognize it3. Trans-bond body enzymes (lipase) don’t recognizeviii. Fats Function- Energy Storage1. Gram of fat, twice as much energy as a gram of sugar (polysaccharide) (way more hydrogen)a. Plants- immobile, bulky storage- starch granulesb. Animals- carry their energy stores around- compactc. Long term storage adipose cellsd. Protect vital organse. Insulation- marine mammals c. Phospholipidsi. 2 fatty acids & phosphate group attached to glycerolii. Fatty acid tails- hydrophobiciii. Phosphate group & attachments form a hydrophilic head (polar)iv. Added to water- self-assemble into bilayer1. Hydrophobic tails pointing toward the interior2. Polar heads exterior3. Cell membranesd. Steroids (completely non polar)i. Four fused rings of carbonii. Carbon skeleton consisting of four fused rings1. Vary in their functional groupsiii. Cholesterol, an important steroid, is a component in animal cell membranes1. Precursor to hormones (testosterone, estrogen)III. Proteinsa. Monomer- amino acidb. Polymer- polypeptides (chains of amino acids)i. Linked by peptide bondsii. Peptide=8-12 amino acidsc. Polypeptide=proteind. Protein are complexi. Consist of one or more polypeptidese. Enzymesi. Protein catalyst- speeds up chemical reactions (without being consumed)ii. Perform their functions repeatedlyiii. –ase = enzymef. 20 Amino Acidsi. Organic molecule with carboxyl & amino groupsii. Amino acids differ in their properties due to differing side chains (R groups)iii. Amino acids are classified according to their SIDE GROUPS ONLY!!!iv. All amino acids have: (backbone)1. One amino group2. One asymmetric carbon3. One carboxyl group4. One