Chapter 3 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into

1. Chapter 3 Lecture Outline See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes.

2. Homework Due Thurs • Ch 1 Concept Review • #3, 6 • #7 List the parts of the scientific method in order and describe each • #13, 14 • Discuss how the birdsong experiment we discussed in class exemplifies the scientific method in terms of the first 4 steps. • Define independent variable vs dependent variable • Inductive reasoning vs deductive reasoning • Ch 2 Concept Review • #10, 12, 13, 15, 16, 17, 18, 19, 21, 22, 23, 24, 25 • Ch 3 Concept Review • 1, 2, 4 ,5, 6, 8, 9, 10, 11, 12

3. Organic Chemistry • All organic molecules contain carbon. • Inorganic molecules do not contain carbon. • Biochemistry is the chemistry of living things.

4. Carbon: The Central Atom • Carbon is the central atom in all organic molecules. • Carbon has unique bonding properties. • Can combine with other carbon atoms in long chains • Can form ring structures

5. Carbon: The Central Atom • Carbon atoms participate in four covalent bonds. • Has four electrons in the outer energy level • Can double bond with oxygen • Can triple bond with other carbon atoms

6. Isomers • Several factors determine the properties of an organic molecule. • The types of atoms in the molecule • The 3-D arrangement of atoms within the molecule • Organic molecules can have the same number and composition of atoms, but can have different arrangements. • These are called isomers. • Molecules with the same empirical formula but different structural formulas

7. Hexose Isomers

8. How Science Works 3.1 • Generic Drugs and Mirror Image Isomers • P49 • http://www.youtube.com/watch?v=G-eMr1kxorc&feature=related

9. The Carbon Skeleton • All organic molecules have a carbon skeleton. • This determines the overall shape of the molecule. • Organic molecules differ in these ways: • The length and arrangement of the carbon skeleton • The kinds and location of atoms attached to it • How the attached atoms are combined together • These combinations are called functional groups. • Functional groups determine the chemical nature of the molecule.

10. Functional Groups

11. Macromolecules of Life • Macromolecules are very large organic molecules. • The most important organic compounds found in living things are: • Carbohydrates • Proteins • Nucleic acids • Lipids

12. Polymers • Carbohydrates, proteins and nucleic acids are polymers. • Polymers are combinations of smaller building blocks. • The building blocks are called monomers. • Polymers are built via dehydration synthesis. • Polymers are broken apart via hydrolysis.

13. Polymers

14. Carbohydrates • Organic molecules composed of carbon, hydrogen and oxygen • All have the general formula CH2O • Names end in –ose • Serve as the primary energy source for most living things • Also serve as structural support • Plant cell walls • Important components of nucleic acids • DNA and RNA

15. Simple Sugars • Simple sugars are described by the number of carbons in the molecule. • Triose-3 carbons • Pentose-5 carbons • Hexose-6 carbons • Examples of simple sugars: • Glucose • Fructose • Galactose

16. Complex Carbohydrates • When two or more simple sugars are combined, they form complex carbohydrates. • Formed via dehydration synthesis • Disaccharides • Two simple sugars • Sucrose • Lactose • Maltose • Trisaccharides • Three simple sugars

17. Polysaccharides • Contain many simple sugars • Examples of polysaccharides: • Starch and glycogen • Used for energy storage in plants (starch) and animals (glycogen) • Cellulose • Important component of plant cell walls • Humans cannot digest cellulose; it is the fiber in our diet. • Helps facilitate movement of food through the digestive tract

18. Complex Carbohydrates

19. Proteins • Proteins are polymers made of amino acids. • An amino acid contains: • Central carbon • Amino group • Carboxyl group • Hydrogen • There are 20 different amino acids.

20. The Structure of Proteins • Amino acids are joined via dehydration synthesis. • The bond formed between amino acids is called a peptide bond. • Several amino acids joined together form polypeptide chains.

21. Primary Structure • The sequence of amino acids in a polypeptide constitutes the primary structure of the protein. • This sequence is dictated by information in genes (DNA). • All levels of protein structure depend on the primary sequence.

22. Secondary Structure • Polypeptides twist and fold into their secondary structure. • Some sequences of amino acids twist into a helix. • This is called an alpha helix. • Some sequences of amino acids remain straight and fold back on themselves. • This is called a beta-pleated sheet.

23. Tertiary Structure • The various alpha helices and beta pleated sheets interact to form a globular structure. • This globular structure is unique for each polypeptide.

24. Quaternary Structure • Some proteins contain more than one polypeptide chain. • Each of these polypeptides has its own unique tertiary structure. • These polypeptides interact to form a more complex globular structure. • Quaternary structure can be stabilized by disulfide bonds.

25. Protein Structure

27. Form and Function • The protein’s overall shape determines its job. • If a protein is not shaped properly, it likely will not work properly. • Example: • Sickle cell anemia • A mutation in the gene causes the protein to have a different shape. • This shape change results in a change in function. • Denaturation: • When heat or other environmental conditions break the bonds that stabilize tertiary structure.

28. Sickle Cell Anemia

29. Types of Proteins • Structural proteins • Important in maintaining the shape of cells and organisms • Collagen • Regulatory proteins • Determine what activities will occur in a protein • Enzymes and hormones • Carrier proteins • Transport molecules from one place to another • Lipoproteins

30. Nucleic Acids • The largest biological molecules • Store and transfer information within a cell • Include DNA and RNA • Are made of nucleotides • 5-carbon sugar • Phosphate group • Nitrogenous group

31. Nucleotides

32. DNA • Each DNA molecule is made of two strands. • Held together by hydrogen bonds between the nitrogenous bases • The bases pair according to base pair rules. • Adenine - thymine • Cytosine - guanine • The two DNA strands are twisted on each other, forming a double helix. • Each DNA strand is divided into segments. • Each segment forms a gene. • Genes are the recipes for proteins. • The sequence of nucleotides in a gene dictate the order of amino acids in a polypeptide.

33. The Structure of DNA

34. DNA and Chromosomes • Each DNA strand has many genes. • Each DNA strand is called a chromosome. • Human cells have 46 chromosomes in each cell. • Each cell copies all of these chromosomes before it divides to pass along to daughter cells.

35. The Functions of DNA • DNA is able to: • Replicate itself • Store information and transmit it to offspring • Direct synthesis of proteins • Mutate (change chemically)

36. The Functions of DNA

37. RNA • RNA is a single-stranded molecule. • Contains uracil instead of thymine • Base pairs with itself and DNA • A-U • G-C • RNA is found in three different forms: • mRNA (messenger RNA) • rRNA (ribosomal RNA) • tRNA (transfer RNA)

38. DNA vs. RNA

39. Lipids • Commonly called fats • Large and nonpolar • Do not dissolve in water • Dissolve in other nonpolar molecules like acetone • Usually have very few oxygen atoms • There are three main types of lipids: • True fats (e.g., pork chop fat and oils) • Phospholipids (membrane components) • Steroids (most hormones)

40. True (neutral) Fats • Used to provide energy • The building blocks of fats • A glycerol molecule • Three fatty acids

41. Saturated vs. Unsaturated Lipids • If the carbon skeleton of a fatty acid has as much hydrogen as possible, the fat is called a saturated fat. • Saturated fats are found in animal tissues and tend to be solid at room temperature. • If the carbons of a fat have double-bonded carbon molecules in them, the fat is called unsaturated fat. • Unsaturated fats are frequently plant fats and are liquids at room temperature. • A polyunsaturated fat has several double bonds. • Fats are important energy storage molecules.

42. Saturated and Unsaturated Fatty Acids

43. Saturated vs unsaturated fats • http://www.youtube.com/watch?v=RtpKswj9KKM&feature=fvsr

44. Phospholipids • Are complex organic molecules that resemble fats but contain phosphate groups • Phospholipids are the major components of cell membranes. • Some are known as lecithins.

45. Steroids • Nonpolar molecules that are arranged in rings of carbon • Steroids are important components of cell membranes. • Cholesterol • Steroids often serve as hormones and serve in regulation of body processes. • Testosterone, estrogen

46. Overview