Macromolecules: Building Blocks of Life

1. Macromolecules Building Complex Molecules That Comprise Living Things

2. Comparison of Terms Four types of organic macromolecules are important in living systems.

3. Macromolecules: Polymers Made of Repeating Monomers

4. Organic Macromolecules Contain Carbon • Question: How many electrons does carbon need to fill its outer energy level? • Answer: Four Each carbon atom can make four covalent bonds with other types of atoms or additional carbons.

6. Synthesis and Breakdown of Macromolecules

7. Dehydration Synthesis / Hydrolysis Dehydration Synthesis Hydrolysis

8. Carbohydrates: Structure • Simple • Monosaccharides= one sugar unit Glucose = blood sugar All cells use glucose for energy

9. CH2OH H HOCH2 O O H HOCH2 CH2OH O H H + O H H H HO H H HO OH H O H HO CH2OH HO CH2OH OH H HO OH HO H HO H HO H HO H Glucose + Fructose HO H Carbohydrates: Structure • Simple • Disaccharides = two sugar units Sucrose & Water

10. Carbohydrates: Structure • Simple • Disaccharides = two sugar units • Sucrose = glucose + fructose table sugar • Lactose = glucose + galactose milk sugar • Maltose = glucose + glucose seed sugar

11. Carbohydrates: Structure • Complex • Polysaccharides= many sugar units • Starch -- storage in plants • Glycogen -- storage in animals • Cellulose -- plant cell walls, indigestible • Chitin -- exoskeletons of insects, fungal cell walls

13. Chitin

14. Carbohydrates: Functions • Energy source • Structural component • Cell-cell communication • C:H:O ratio 1:2:1

15. Carbohydrates: Dietary Recommendations • 58% of calories from carbohydrates • No more than 10% of calories from simple, refined sugars • Emphasize • Complex Carbohydrates • Starch • Fiber (cellulose) • Naturally-occurring simple carbohydrates • Fructose from fruit • Lactose from milk

16. Macronutrients As Energy Sources

17. Applying Your Knowledge • Which molecule consists of two sugar units? • Which choice best describes glycogen? • Which type of molecule provides the basic energy for your cells? • Which type of molecule is found in milk? • Monosaccharide • Polysaccharide • Disacharide

18. Macromolecules: Polymers Made of Repeating Monomers

19. Lipids: Structure • Triglyceride—predominant form in diet • One molecule of glycerol • Three fatty acids • C:H:O ratio- 1:2:very few

20. Lipids: Structure • Types of Fatty Acids • Saturated – 2H per internal carbon • Unsaturated -- <2H per internal carbon one or more double bonds • Monounsaturated – one double bond • Polyunsaturated – more than one double bond

21. H H H H H H C H H H H C C C C C O O O OH OH OH C C C C C C O O O O O O OH OH OH C C H H H H C C H H H H C C H H H H C C C O O O H H H H C C H H H H C C H H H H C C H C H H C H H C H C C C C C C H H H H H H H H H H H H H H H H H H C C C H H H H H H C C C H H H H H H H H H HOH HOH HOH TriglycerideFormation Triglyceride Glycerol RemoveTheseWaters Add 3FattyAcids 3 Waters

22. Which Is a Source of Unsaturated Fatty Acids? Linseed Oil Beef Fat

23. Lipids: Structure • Phospholipid—component of cell membranes PolarHead Glycerol Fatty Acid Tails Hydrophilic Hydrophobic

24. Lipids: Structure • Steroids • Linked carbon rings • Natural body components • Hormones • Cholesterol

25. Estradiol Testosterone Steroids Cholesterol

26. Lipids: Functions • Concentrated energy source • Structural components of cell membranes • Phospholipids • Cholesterol • Communication • Steroid Hormones • Protection from water • Waxes Cholesterol Phospholipids

27. Lipids: Dietary Recommendations • < 30% of calories from lipids • < 10% of calories from saturated fats • Limit cholesterol to 300 mg/day • Avoid “trans” fatty acids in partially hydrogenated products • Emphasize • Unsaturated fatty acids from vegetables,fish, legumes,and nuts • Oils: mono- or polyunsaturated

28. Macronutrients As Energy Sources

29. Applying Your Knowledge • Which molecule is made of a series of carbon rings? • Which molecule has more than one double bond? • Which molecule has 2H for each internal carbon? • Which molecule has one double bond? • Polyunsaturated fatty acid • Cholesterol • Monounsaturated fatty acid • Saturated fatty acid

30. Macromolecules: Polymers Made of Repeating Monomers

31. Proteins: Structure • Primary structure = chain of amino acids • Amino acids have common features Carboxylic AcidGroup AminoGroup     R “Alpha”Carbon The “R” GroupDiffers for Each Amino Acid

32. Carboxylic Acid     Group AminoGroup   “Alpha”Carbon Amino Acids: Phenylalanine Structure Phenylalanine“R” Group

33. Carboxylic Acid     Group AminoGroup   Amino Acids: Leucine Structure Leucine “R”     Group

34. Proteins: StructureForming the Protein Chain Phenylalanine Leucine Dehydration Synthesis between COOH & NH2

35. Proteins: StructureForming the Protein Chain The Peptide Bond Water Phenylalanine-Leucine Dipeptide

36. Four Levels of Protein Structure Tertiary(Folding by R-group interactions) Primary(Sequence) Quaternary(Two or more chains associating) Secondary(Coiling by Hydrogen Bonding)

37. Four Levels of Protein Structure Primary Structure = sequence of amino acids in chain

38. Four Levels of Protein Structure • Secondary Structure Folded structure due to hydrogen bonds between the amino and acid groups of amino acids N C N C H O H O or O H O H N C N C

39. Found in most proteins Found in silk

40. Four Levels of Protein Structure • Tertiary Structure: Three dimensional folded structure due to attractions and repulsions between R groups Can involve covalent bonding hydrogen bonding ionic interactions hydrophilic and hydrophobic interactions

42. StraightHair NaturallyCurlyHair |S|S| |S|S| |S|S| |S|S| |S|S| |S|S| |S|S| |S|S| |S|S| |S|S| Hair Curling

43. Four Levels of Protein Structure • Quaternary Structure: Association of two or more protein chains eg. Hemoglobin is composed of 4 protein chains 2 are called alpha hemoglobin 2 are called beta hemoglobin

44. Proteins: Functions • Structural Component of Cells • Control of Metabolic Reactions: enzymes • Growth and Repair • Communication • Protein Hormones • Cell Receptors • Energy source • C:H:O ratio –no reliable ratio • For proteins Protein Protein

45. Proteins: Dietary Recommendations • 12% of calories from proteins • 8 essential amino acids obtained from • Lean sources of animal protein • Complementary plant proteins • Beans + Grains • Beans + Seeds

46. Applying Your Knowledge • Which structure results from hydrogen bonding? • Which structure involves an association of two or more protein chains? • Which structure describes the linear sequence of amino acids? • Which structure depends upon interactions between the R groups of the amino acids? • Primary • Secondary • Tertiary • Quaternary

47. Nucleic Acids • Nucleic acids store, transmit, and help express hereditary information • The amino acid sequence of a polypeptide is programmed by a unit of inheritance called a gene • Genes are made of DNA, a nucleic acid made of monomers called nucleotides

48. Two Types of Nucleic Acids • There are two types of nucleic acids • Deoxyribonucleic acid (DNA) • Ribonucleic acid (RNA) • DNA provides directions for its own replication • DNA directs synthesis of messenger RNA (mRNA) and, through mRNA, controls protein synthesis • Protein synthesis occurs on ribosomes

49. 1 DNA Figure 5.25-1 Synthesis ofmRNA mRNA NUCLEUS CYTOPLASM

50. 1 2 DNA Figure 5.25-2 Synthesis ofmRNA mRNA NUCLEUS CYTOPLASM mRNA Movement ofmRNA intocytoplasm