PowerPoint Presentation3.1 Why Is Carbon So Important in Biological Molecules?Slide 3Slide 43.2 How Are Organic Molecules Synthesized?Slide 6Author Animation: Monomers and PolymersAuthor Animation: HydrolysisSlide 9Slide 10Slide 113.3 What Are Carbohydrates?Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Author Animation: Carbohydrate Structure and FunctionCellulose Structure and FunctionSlide 223.4 What Are Lipids?Author Animation: LipidsSlide 25Slide 26Author Animation: TriglyceridesSlide 28Slide 29Slide 30PhospholipidsSlide 32Author Animation: Steroids3.5 What Are Proteins?Slide 35Amino Acid DiversitySlide 37Slide 38Author Animation: Protein StructureThe Four Levels of Protein StructureThe Pleated Sheet: An Example of Secondary StructureSlide 423.6 What Are Nucleic Acids?Deoxyribose NucleotideSlide 45Slide 46Deoxyribonucleic AcidChapter 3Biological Molecules3.1 Why Is Carbon So Important in Biological Molecules?Organic/inorganic molecules and functional groups–Organic: consisting of a carbon skeleton bonded to hydrogen atoms –Inorganic: carbon dioxide and all molecules without carbon Whole Foods recallsSkinny Girl not so skinny...Organic/inorganic molecules and functional groups (continued)– CARBON atom is versatile – Has 4 electrons in an outermost shell – CAN hold up to 8 electrons in outer shell –Therefore, a carbon atom can become stable by forming up to four bonds –So…organic molecules can assume complex shapes, including branched chains, rings, sheets, and helices ??vacant spotelectronFunctional groups: determine the characteristics and chemical reactivity of the molecules– Less stable than the carbon backbone & more likely to participate in chemical reactions3.2 How Are Organic Molecules Synthesized?– Small organic molecules (called monomers) are joined to form longer molecules (called polymers) – Monomers are joined together through dehydration synthesis (or CONDENSATION RXN), resulting in the loss of a water molecule (H2O) from the reacting molecule dehydrationsynthesis Fig. 3-1-Or-Condensation rxn.Polymers are broken apart through hydrolysis (“water cutting”)– Water is broken into H and OH and is used to break the bond between monomers hydrolysis Fig. 3-2Author Animation: Monomers and PolymersAuthor Animation: HydrolysisAll biological molecules fall into one of four categories1. Carbohydrates 2. Lipids 3. Proteins 4. Nucleotides/nucleic acidsTable 3-2 (1 of 2)Table 3-2 (2 of 2)3.3 What Are Carbohydrates?Carbohydrate molecules are composed of C, H, and O in the ratio of 1:2:1– If a carbohydrate consists of just one sugar molecule, it is a monosaccharide – Two linked monosaccharides form a disaccharide – A polymer of many monosaccharides is a polysaccharide – Important energy sources for most organisms – Most small carbohydrates are water-soluble due to the polar OH functional groupsThere are several monosaccharides with slightly different structures– Example: monosaccharides – Glucose (C6H12O6): the most common in living organisms – sugar dissolving in water hydrogenbondhydroxylgroupwater Fig. 3-3Additional monosaccharides are: – Fructose (“fruit sugar” found in fruits, corn syrup and honey)– Galactose (“milk sugar” found in lactose) galactosefructoseFig. 3-5Additional monosaccharides are: (continued) – Ribose and deoxyribose (found in RNA and DNA, respectively) ribose deoxyriboseNote “missing”oxygen atomFig. 3-6Disaccharides consist of two monosaccharides linked by dehydration synthesis– Disaccharides are two-part sugars– They are used for short-term energy storage– When energy is required, they are broken apart into their monosaccharide subunits by hydroysisglucose fructosesucrosedehydration synthesisFig. 3-7Examples of disaccharides include:–Sucrose (table sugar) = glucose + fructose –Lactose (milk sugar) = glucose + galactose–Maltose (malt sugar) = glucose + glucosePolysaccharides are chains of simple sugars– Starch, an energy-storage molecule in plants, formed in roots and seeds– Glycogen, an energy-storage molecule in animals, found in the liver and muscles– Both are polymers of glucose molecules (b) A starch molecule(a) Potato cells(c) Detail of a starch moleculestarch grainsFig. 3-8Polysaccharides are chains of simple sugars (continued)– Many organisms use polysaccharides as a structural material – Cellulose (a polymer of glucose) is one of the most important structural polysaccharides – Found in the cell walls of plants – Indigestible for most animals– Chemical formula for STARCH and CELLULOSE is the same, but they are VERY different– Starch (easily digested) vs. cellulose (indigestible for most animals)Author Animation: Carbohydrate Structure and FunctionCellulose Structure and Function Fig. 3-9Polysaccharides are chains of simple sugars (continued)– Chitin (a polymer of modified glucose units) is found in:– Outer coverings of insects, crabs, and spidersFig. 3-103.4 What Are Lipids?Lipids are a diverse group of molecules that contain regions composed almost entirely of hydrogen and carbon– Large chains of nonpolar hydrocarbons– Hydrophobic and water insoluble – Used for energy storage–Waterproof coverings on plant and animal bodies –Primary component of cellular membranes Fig. 3-11aAuthor Animation: LipidsLipids are classified into three major groups1. Oils, fats, and waxes2. Phospholipids3. Steriods, ???#1: Oils, fats, waxes (examples of triglycerides)– made of one or more fatty acid and subunits – 3 fatty acids + glycerol– triglyceride glycerolfatty acidstriglycerideFig. 3-12Author Animation: TriglyceridesOils, fats, and waxes (continued)– Fats that are solid at room temperature are saturated – Fats that are liquid at room temperature are unsaturated (linked to heart disease) Fig. 3-13bFig. 3-13aOils, fats, and waxes (continued)– Waxes are highly saturated and solid at room temperature – Waxes form waterproof coatings on leaves/stems in plants, fur in mammals, and insect exoskeletons– Used to build honeycomb structures Fig. 3-11b#2: Phospholipids– Form plasma membranes around all cells – They have hydrophobic and hydrophilic portions – Polar functional groups form the “head” and are water-soluble – Nonpolar fatty acids form the “tails” and are water insoluble Lipid bilayer of cell membranePhospholipidsFig.
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