1. Molecules of Life I CHAPTER 3 Carbon/Organic Chemistry Bonding in hydrocarbons Functional groups Monomers and Polymers, Linking and Breaking Carbohydrates Monosaccharides Disaccharides Polysaccharides Lipids Fats and Oils Steroids Phospholipids

2. Relevance of Biomolecules in Everyday Life completely

3. Organic Molecules A cell is mostly water. –The rest of the cell consists mostly of carbon-based molecules. –Organic chemistry is the study of carbon compounds. Carbon is a versatile atom. –It has four electrons in an outer shell that holds eight. –Carbon can share its electrons with other atoms to form up to four covalent bonds. Carbon can use its bonds to: –Attach to other carbons. –Form an endless diversity of carbon skeletons.

4. Figure 3.2 Each Carbon Atom Makes Four Covalent Bonds to Other Atoms

5. Figure 3.3 Carbon Connects With Hydrogens to Form Hydrocarbons Methane (CH 4 ) is the simplest hydrocarbon

6. Figure 3.4 Other Hydrocarbons in Our Lives

7. Molecules of Life I CHAPTER 3 Carbon/Organic Chemistry Bonding in hydrocarbons Functional groups Monomers and Polymers, Linking and Breaking Carbohydrates Monosaccharides Disaccharides Polysaccharides Lipids Fats and Oils Steroids Phospholipids

8. Each type of organic molecule has a unique three- dimensional shape that defines its function in an organism. –The molecules of your body recognize one another based on their shapes. –Even slight differences in molecular arrangement effects the chemical behavior of a molecule –Certain groups of atoms confer chemical reactivity to a molecule (functional groups) Structure Gives Rise to Function Isomers

9. Figure 3.5 Functional Groups That Contribute to Molecular Behavior

10. Molecules of Life I CHAPTER 3 Carbon/Organic Chemistry Bonding in hydrocarbons Functional groups Monomers and Polymers, Linking and Breaking Carbohydrates Monosaccharides Disaccharides Polysaccharides Lipids Fats and Oils Steroids Phospholipids

11. Giant Molecules from Smaller Building Blocks On a molecular scale, many of life’s molecules are gigantic. –Biologists call them macromolecules. –Examples: DNA, carbohydrates Most macromolecules are polymers. –Polymers are made by stringing together many smaller molecules called monomers. –Cells link monomers by dehydration reactions. monomers polymer

12. Figure 3.6a Dehydration/Condensation Synthesis of a Polymer

13. Figure 3.6b Hydrolytic Breakdown of a Polymer

14. Biological Molecules There are four categories of large molecules in cells: –Carbohydrates –Lipids –Proteins –Nucleic acids

15. Molecules of Life I CHAPTER 3 Carbon/Organic Chemistry Bonding in hydrocarbons Functional groups Monomers and Polymers, Linking and Breaking Carbohydrates Monosaccharides Disaccharides Polysaccharides Lipids Fats and Oils Steroids Phospholipids

16. Carbohydrates Carbohydrates are composed of: –Simple sugars (monosaccharides) found in table sugar, fruit, and soft drinks. –Complex sugars (polysaccharides) found in pasta and potatoes as well as the cells of plants

17. Simple Sugars: Monosaccharides Monosaccharides are simple sugars. –Glucose is found in sports drinks. –Fructose is found in fruit. Honey contains both glucose and fructose.

18. Glucose and Fructose are Structural Isomers Same molecular formula but different structural formulas Carbonyl functional groups makes these sugars reactive (can lose electrons) Hydroxyl groups make these sugars polar and water soluble

19. Glucose Fructose Simple Sugars Usually “Round up” into Rings Straight chain form Ring form

20. Disaccharides A disaccharide is a double sugar. –It is constructed from two monosaccharides. Disaccharides are joined through a dehydration reaction. Disaccharides

21. Figure 3.11 Lactose is a disaccharide that some people cannot digest as adults

22. Table Sugar (Sucrose) is a Disaccharide

23. Polysaccharides Complex carbohydrates are called polysaccharides. –They are long chains of sugar units. –They are polymers of monosaccharides. Polysaccharides can be classified by function –Energy storage polysaccharides –Structural support polysaccharides Polysaccharides

24. Figure 3.13 Three Polysaccharides Energy storage Structural support in plants

25. Cellulose Cannot Be Broken into Glucose Monosaccharides By Mammals Plant-eaters have resident bacteria and protozoa that break the cellulose into glucose within their digestive system

26. Molecules of Life I CHAPTER 3 Carbon/Organic Chemistry Bonding in hydrocarbons Functional groups Monomers and Polymers, Linking and Breaking Carbohydrates Monosaccharides Disaccharides Polysaccharides Lipids Fats and Oils Steroids Phospholipids

27. Lipids Lipids are not water soluble (hydrophobic) –Lipids are mostly composed of hydrocarbon chains or rings –They do not mix with water. Important lipid polymers that we will study are: –Fats and Oils –Phospholipids –Steroids

28. Fats and Oils (Triglycerides) A fat or oil consists of a four part chain of hydrocarbons (a triglyceride) –Triglyceride is a combination of glycerol and three fatty acids. Fats perform essential functions in the human body: –Energy storage –Cushioning –Insulation

29. A Fat or Oil is Made From Three Fatty Acids and One Glycerol Dehydration reactions Fats

30. Unsaturated fatty acids (One or more C=C bonds) –Have less than the maximum number of hydrogens bonded to the carbons. –Tend to be solid at room temperature, e.g.. butter Saturated fatty acids (Only C-C bonds) –Have the maximum number of hydrogens bonded to the carbons. –Tend to be liquid at room temperature, e.g. corn oil Saturated and Unsaturated Fats (Triglycerides)

31. Not all fats are unhealthy. –Some fats perform important functions in the body and are essential to a healthy diet. –Many unsaturated fats and cis-fats are good for you Healthy Triglycerides

32. Steroids Steroids are very different from fats in structure and function. –The carbon skeleton is bent to form four fused rings. Cholesterol is the “base steroid” from which your body produces other steroids. –Example: sex hormones

33. Steroids Consist of Four Joined Rings Biological role: Helps keep cell wrappers (membranes) fluid and flexible Biological role: Act as chemical messengers (hormones) to stimulate certain body parts

34. Phospholipids: Barrier-forming molecules Phospholipids organize into double-layered spheres in water H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O

35. Molecules of Life I CHAPTER 3 Carbon/Organic Chemistry Bonding in hydrocarbons Functional groups Monomers and Polymers, Linking and Breaking Carbohydrates Monosaccharides Disaccharides Polysaccharides LipidsProteins and Nucleic Acids Fats and Oils will be discussed next time Steroids Phospholipids