Organic and Inorganic Compounds: Molecules of Life

1. 0 Chapter 3 The Molecules of Cells

2. List the following items and tell whether they are organic or inorganic. • Wool • Cotton • Glass • Paper • Potted Plant • Carbon Dioxide (CO2) DO NOW

3. 0 Got Lactose? Many people in the world suffer from lactose intolerancelacking an enzyme that digests lactose, a sugar found in milk Lactose intolerance: does not affect the consumption of beverages made from soy or rice Common in those of non-European backgrounds. Common in people over the age of 2.

4. 0 INTRODUCTION TO ORGANIC COMPOUNDS Space-fillingmodel Structuralformula Ball-and-stickmodel 3.1 Life’s molecular diversity is based on the properties of carbon A carbon atom can form four covalent bonds Allowing it to build large and diverse organic compounds H H H H C C H H H Methane H The 4 single bonds of carbon point to the corners of a tetrahedron. Figure 3.1A

5. Carbon is able to form an immense diversity of organic molecules because of carbon's:   • tendency to form covalent bonds.   • ability to bond with up to four other atoms.   • capacity to form single and double bonds.   • ability to bond together to form extensive, branched, or unbranched "carbon skeletons."  

6. 0 H H H H H C C C C C H H H H H H H H H Ethane Propane Carbon skeletons vary in length. H C H H H H H H H H C C C C C C C H H H H H H H H H H H Butane Isobutane Skeletons may be unbranched or branched. Carbon chains vary in many ways H H H H H H H H C C C H H C C C H C C H H H H H 1-Butene 2-Butene Skeletons may have double bonds, which can vary in location. H H H C C H H H H C C C C H H H C C H C C H H C H H C H H H Benzene Cyclohexane Skeletons may be arranged in rings. Figure 3.1A

7. 0 Hydrocarbons: Are organic compounds.   Are composed of hydrogen atoms that are attached to carbon skeletons.   Contain carbon and hydrogen atoms.   Consist of atoms linked by single bonds.   Some carbon compounds are isomers-molecules with the same molecular formula but different structures.

8. 0 3.2 Functional groups help determine the properties of organic compounds Examples of functional groups Table 3.2

9. 0 OH Estradiol HO Functional groups are particular groupings of atoms that give organic molecules particular properties Female lion OH O Testosterone Figure 3.2 Male lion

10. 0 3.3 Cells make a huge number of large molecules from a small set of small molecules The four main classes of biological molecules are carbohydrates, lipids, proteins, and nucleic acids Many of the molecules are gigantic and are called macromolecules

11. 0 H OH H OH OH H Cells make most of their large molecules by joining smaller organic molecules into chains called polymers Cells link monomers to form polymers by a dehydration reaction (condensation synthesis). Examples of polymers: Proteins (Polypeptides) Lipids Nucleic acids Polysaccharides (Carbohydrates) Short polymer Short polymer Unlinked monomer Unlinked monomer H2O Dehydration reaction Dehydration reaction OH H OH H Longer polymer Figure 3.3A

12. 0 H2O H OH Polymers are broken down to monomers by the reverse process, hydrolysis Hydrolysis H OH H OH Figure 3.3B

13. 0 CARBOHYDRATES 3.4 Monosaccharides are the simplest carbohydrates The carbohydrate monomers are monosaccharides Figure 3.4A

14. 0 A monosaccharide has a formula that is a multiple of CH2O and contains hydroxyl groups and a carbonyl group Many sugars end in the suffix –ose.

15. 0 H O H C C H OH OH H C C O The monosaccharides glucose and fructose are isomers that contain the same atoms but in different arrangements HO H C HO H C OH C H C H OH H OH C C OH H C OH H C H OH H H Figure 3.4B Glucose Fructose

16. 0 CH2OH 6 CH2OH C O 5 H O O H H H H H C C 1 4 OH H OH H OH HO OH Monosaccharides can also occur as ring structures OH C C 2 3 H OH H OH Simplified structure Structural formula Abbreviated structure Figure 3.4C

17. 0 CH2OH 3.5 Cells link two single sugars to form disaccharides Monosaccharides can join to form disaccharides such as sucrose (table sugar) and maltose (brewing sugar) A disaccharide forms when two monosaccharides join by dehydration synthesis. CH2OH O O H H H H H H OH H OH H O OH H HO OH H OH H OH Glucose Glucose H2O CH2OH CH2OH O O H H H H H H OH OH H H O OH HO H OH H OH Maltose Figure 3.5

18. 0 CONNECTION 3.6 How sweet is sweet? Various types of molecules, including nonsugars Taste sweet because they bind to “sweet” receptors on the tongue Table 3.6

19. 0 3.7 Polysaccharides are long chains of sugar units Polysaccharides are polymers of monosaccharides Linked together by dehydration reactions

20. 0 Glucose monomer STARCH Starch granules in potato tuber cells O O O O O O O O O O O Glycogen granules in muscle tissue Starch and glycogen are polysaccharides that store sugar for later use Cellulose is a polysaccharide found in plant cell walls GLYCOGEN O O O O O O O O O O O O O Cellulose fibrils in a plant cell wall CELLULOSE O O OH Cellulose molecules O O O O O OH O O O O O O O O O O O O O O O O Figure 3.7

21. 0 LIPIDS 3.8 Fats are lipids that are mostly energy-storage molecules Lipids are diverse compounds that consist mainly of carbon and hydrogen atoms linked by nonpolar covalent bonds

22. 0 Lipids are grouped together because they are hydrophobic and nonpolar. Figure 3.8A

23. Fats, also called triglycerides • Are lipids (a type of fat) whose main function is energy storage •  Consist of glycerol (alcohol with three carbons) linked to three fatty acids • Are hydrophobic.   H H H H H C C C OH OH OH Glycerol HO C O H2O CH2 CH2 CH2 CH2 CH2 Fatty acid CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH3

24. Unsaturated-Fatty acids with double bonds between some of their carbons • Ex. Plant fats • Liquids at room temperature • Saturated-fats with the maximum number of hydrogens • Ex. Animal fats • All are solids at room temperature. • Eating too many leads to atherosclerosis

25. 0 H H H H H C C H C O O O C C C O O O CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH CH2 CH2 CH CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH3 CH3 CH3

26. Hydrogenated-unsaturated fats have been converted to saturated fats by adding hydrogen. • Trans Fat-an unsaturated fat that has been converted to a saturated fat by hydrogenation.

27. 0 3.9 Phospholipids, waxes, and steroids are lipids with a variety of functions Phospholipids are a major component of cell membranes Composed of one glycerol molecule linked to one phosphate group and two fatty acids. Waxes form waterproof coatings Steroids are often hormones CH3 H3C CH3 CH3 CH3 Figure 3.9 HO

28. 0 CONNECTION 3.10 Anabolic steroids pose health risks Anabolic steroids Are synthetic variants of testosterone Can cause serious health problems

29. 0 PROTEINS 3.11 Proteins are essential to the structures and activities of life A protein is a polymer constructed from amino acid monomers Types of Proteins: Contractile proteins   Antibodies   Enzymes   Signal proteins

30. 0 Proteins Are involved in almost all of a cell’s activities As enzymes They regulate chemical reactions. Figure 3.11

31. 0 3.12 Proteins are made from amino acids linked by peptide bonds Protein diversity is based on different arrangements of a common set of 20 amino acid monomers Proteins differ from one another because the sequence of amino acids in the polypeptide chain differs from protein to protein.

32. 0 H Each amino acid contains An amino group A carboxyl group An R group, which distinguishes each of the 20 different amino acids O H C N C H OH R Amino group Carboxyl (acid) group Figure 3.12A

33. 0 H H H H H H O O O N C C N C C N C C OH OH H H H OH CH2 CH2 CH2 Each amino acid has specific properties Based on its structure CH OH C CH3 CH3 OH O Leucine (Leu) Serine (Ser) Aspartic acid (Asp) Hydrophobic Hydrophilic Figure 3.12B

34. 0 Peptide bond Carboxyl group Amino group H H Dehydration reaction H O H Cells link amino acids together By dehydration synthesis The bonds between amino acid monomers Are called peptide bonds H H O O O H N C C + N C C N C C N C C H OH OH H OH H H R R R R H2O Amino acid Amino acid Dipeptide Figure 3.12C

35. 0 3.13 A protein’s specific shape determines its function A protein consists of one or more polypeptide chains Folded into a unique shape that determines the protein’s function Groove Groove Figure 3.13A Figure 3.13B

36. Factors can result in the denaturation of a protein   • Heat   • Changes in pH   • Chemicals that destroy hydrogen bonds   • Changes in salt concentration  

37. 0 3.14 A protein’s shape depends on four levels of structure

38. 0 Levels of Protein Structure Primary Structure A protein’s primary structure Is the sequence of amino acids forming its polypeptide chains Leu Met Asn Val Pro Ala Val Ile Arg Cys Val Lys Phe Ala Glu His Gly Val Ser Lys Primary structure Thr Val Gly Pro Ala Val Asp Arg Leu Gly Ser Amino acids Figure 3.14A

39. 0 Secondary structure A protein’s secondary structure is the coiling or folding of the chain, stabilized by hydrogen bonding Ex. Alpha helix or Pleated Sheet Amino acids Hydrogen bond O H H O C C C N N H C O C C C R N C C N H H H O N C C O C C C N O H H C N C N O H C H C H C N N C N O C O N H N C H O O C R C C O C O H H H C C O C N H O N C C C N C H Secondary structure C C O O H N C C O N H C C H H N H N O O N C C N C O C H N H N C C H O C O C C N H C C C N O H C O Alpha helix Pleated sheet Figure 3.14B

40. 0 Tertiary Structure A protein’s tertiary structure is the overall three-dimensional shape of a polypeptide Tertiary structure Polypeptide (single subunit of transthyretin) Figure 3.14C

41. 0 Polypeptide chain Quaternary Structure A protein’s quaternary structure Results from the association of two or more polypeptide chains Quaternary structure Transthyretin, with four identical polypeptide subunits Collagen Figure 3.14D

42. 0 NUCLEIC ACIDS 3.16 Nucleic acids are information-rich polymers of nucleotides Nucleic acids such as DNA and RNA serve as the blueprints for proteins and thus control the life of a cell Genetic information is encoded in the sequence of nucleotides in DNA.

43. 0 H H N The monomers of nucleic acids are nucleotides composed of a sugar, phosphate, and nitrogenous base Nucleotides   Contain nitrogenous bases.   Contain sugar molecules.   Contain phosphate groups.   Can be linked together to form nucleic acids.   N N H OH N H N O P O CH2 Nitrogenous base (A) O O H H Phosphate group H H OH H Sugar Figure 3.16A

44. 0 Nucleotide A T The sugar and phosphate Form the backbone for the nucleic acid or polynucleotide C G T Sugar-phosphate backbone Figure 3.16B

45. 0 C A T C G C G A T C G DNA consists of two polynucleotides twisted around each other in a double helix and contains thymine. Stretches of a DNA molecule, called genes, program the amino acid sequences of proteins A T A T Base pair G C T A A T A T Figure 3.16C

46. 0 RNA, by contrast is a single-stranded polynucleotide and contains uracil.