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Molecules of Life
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  1. Molecules of Life Compounds that contain carbon What are biological molecules? What are organic molecules? Nucleic Acids Carbohydrates Lipids Proteins

  2. Organic Molecules What is a cell made up of mostly? Mostly water, but what else? Carbon based molecules Why is carbon so significant for these molecules?

  3. Recall that an atom’s bonding ability • Is related to the number of electrons it must share to complete its outer shell Atomic number?

  4. What does sharing electrons with other atoms, in four covalent bonds mean? Each carbon acts as an ‘intersection’ With 4 different branch points Creates endless variety of (organic) carbon molecules Vary in length

  5. Diversity of Carbon-Based Molecules Different location of double bonds Unbranched or branched Rings Activity: Diversity of Carbon-Based Molecules http://wps.aw.com/bc_campbell_essentials_3/0,11844,3107816-,00.html

  6. Methane What is a hydrocarbon? Is a hydrocarbon ……….. Carbon & Hydrogen Methane is the simplest

  7. Examples of larger hydrocarbons?? Octane (in gasoline) Fatty foods

  8. Biological Molecules Food ‘Carbs’ Structural Sugar Storage Glucose Enzymes Glycogen Antibodies Cellulose Oils Fatty acids (sat & unsat) DNA RNA Butter

  9. Carbohydrates What type of sugar is found in the following? Small (simple) sugar molecules Examples? • Monosaccharides Glucose Fructose • Disaccharides Lactose Sucrose Long starch molecules in pasta, potatoes Examples? • Polysaccharides Starch Cellulose These are our primary sources of dietary energy In plants, carbs used as building material

  10. Monosaccharides What type of sugar is found a sports drink? Glucose What type of sugar is found in fruit? Fructose

  11. What about honey? Its really sweet? Why? It contains both glucose and fructose

  12. Glucose and Fructose Have the same formula… C6H12O6 Why are they ‘different’? They are isomers L-Dopa

  13. Form rings in aqueous solutions Which sugar is this? Glucose Why are the carbons numbered?

  14. Disaccharides Are ‘double sugars’ What are they constructed from? 2 monosaccharides Disaccharides

  15. Disaccharides Maltose: glucose and glucose Lactose: galactose and glucose Sucrose: glucose and fructose

  16. Lactose, another disaccharide • Some people have trouble digesting lactose • Its a condition called lactose intolerance • Missing gene for lactase enzyme

  17. Sucrose The most common disaccharide is sucrose, what do you know it as? Common table sugar What plants do we use to extract table sugar? Sugar cane Roots of sugar beets

  18. Polysaccharides Are long chains of sugar units (monosaccharides) (polymers) What are some polysaccharides? Starch Glycogen Cellulose Polysaccharides

  19. Describe some characteristics of the following: Starch Potatoes and grains are major sources of starch in the human diet Glycogen Liver, muscle cells break down glycogen to release glucose when needed for energy Cellulose Structural component, dietary fiber

  20. Biological Macromolecule: Carbohydrates Function: Monomer: • Dietary energy • Storage • Plant structure Examples: • Monosaccharides (simple sugars) (glucose, fructose) • Disaccharides (double sugars) (maltose, lactose, sucrose) • Polysaccharides (long polymers) (starch, glycogen, cellulose)

  21. Lipids Butter, lard, margarine, and salad oil Do these lipids mix well with water? Activity: Lipids http://wps.aw.com/bc_campbell_essentials_3/0,11844,3107816-,00.html Fats

  22. Lipids This diverse group of molecules includes? Fatty acids (energy storage, cushioning, insulation) A biological compound consisting of three fatty acids linked to one glycerol molecule Steroids (cholesterol, in membranes) Characterized by a carbon skeleton consisting of four rings with various functional groups attached

  23. Fatty Acids triglycerides Technically called? A fat molecule: Glycerol 3 Fatty acids ‘saturated’ ‘unsaturated’ Double bond ‘unsaturated”

  24. Unsaturated fatty acids (plant oils) Have less than the maximum number of hydrogens bonded to the carbons Saturated fatty acids (butter) Have the maximum number of hydrogens bonded to the carbons

  25. Double Bonds What is the significance of the number of double bonds in the hydrocarbon tails? • Unsaturated fats tend to be liquids at room temperature Example? vegetable oils Impact on health? unsaturated fats are safer • Saturated fats are solid at room temperature Example? butter and lard Impact on health? Saturated fats in the diet can lead to heart disease

  26. Steroids How does the structure differ from fatty acids? Ring structure, various functional groups How does the function differ from fatty acids? Functional groups affect function • causes differences between the hormones estrogen and testosterone Example? (anatomical and physical development) • cholesterol in membranes

  27. Biological Macromolecule: Lipids Function: Monomer: • Long term energy storage • Hormones Examples: (triglycerides) • Fats, oils (butter, lard, margarine, salad ols) • Steroids (lipid rings) (cholesterol, hormones)

  28. Proteins What is a protein? • A three-dimensional biological polymer • Constructed from a set of 20 different monomers • Monomers are amino acids Activity: Protein Functions Activity: Protein Structure http://wps.aw.com/bc_campbell_essentials_3/0,11844,3107816-,00.html

  29. Activity: Protein Structure Activity: Protein Functions http://wps.aw.com/bc_campbell_essentials_3/0,11844,3107816-,00.html Structural Proteins Receptor Proteins Enzymes Storage Proteins Signal Proteins Contractile Proteins Transport Proteins Sensory Proteins Gene Regulatory Proteins Defensive Proteins

  30. Structure, Function Storage 1. Hair, silk of spiders Contractile 2. Antibodies Transport 3. Detect environmental changes Defense 4. Change rate of a reaction Receptor 5. Control genes Enzymes 6. Cell communication Signal 7. Trigger changes inside cell Sensory 8. Carry molecules from place to place Gene regulatory 9. Stockpile building materials Structural 10. Can move parts of a cell or animal

  31. The Monomers What does each amino acid monomer consist of? Carboxyl group Amino group • A central carbon atom • Bonded to four covalent partners • Each side group is unique • Identifies each amino acid’s characteristics

  32. Examples of 2 different amino acids and their side groups

  33. Structure Proteins are complex! Primary • To simplify, we’ll describe them in terms of 4 levels of structure: • a particular # and sequence of amino acids Secondary • turns and folds, alpha helix, pleated sheet Tertiary • irregular loops and folds, 3-D shape Quaternary • 2 or more polypeptides combined

  34. What do they look like? Secondary structure Quaternary structure • Primary structure • Tertiary structure

  35. Biological Macromolecule: Proteins Monomer: Function: Carboxyl group Amino group • Many! • Change rate of reaction • Carry molecules • Cell communication Examples: • Enzyme (lactase) • Transport (hemoglobin) = 20 amino acids • Defense (antibodies)

  36. Nucleic Acids What are nucleic acids? The cells information storage molecules • There are two types of nucleic acids • DNA, deoxyribonucleic acid RNA, ribonucleic acid • These ‘work together’ to synthesize protein Activity: Nucleic Acid Functions

  37. Synthesizing Protein What does DNA do? It carries instructions for building all the proteins

  38. What does DNA do? Information in DNA is transcribed into RNA

  39. What does RNA do? RNA acts as an intermediary in the protein-making process DNA RNA Protein

  40. What else does RNA do? RNA then translates the (transcribed) information into the primary structure of proteins What is the primary structure of proteins?

  41. What does protein do? Proteins carry out cell activities

  42. Structure What is the structure of nucleic acids? Phosphate group They are polymers of nucleotides What do the nucleotides contain? Nitrogen base Sugar (Deoxyribose)

  43. What do DNA nucleotides contain? Each DNA nucleotide has one of the following bases: 2 1 • Adenine (A) • Thymine (T) • Cytosine (C) 4 3 • Guanine (G) Which one is which? Match the numbers to the base

  44. Polymers of nucleotides Nucleotide Linked into long chains Called polynucleotides or DNA strands A sugar-phosphate backbone joins them together Bases Activity: Nucleic Acid Structure

  45. 2 DNA strands form helix How does this happen? Via complementary binding (and hydrogen bonding) A always binds with T C always binds with G

  46. RNA, different from DNA It has the base uracil (U) instead of thymine (T) in DNA The RNA sugar has 2 OH groups vs 1 in DNA (Ribose vs deoxyribose)

  47. Biological Macromolecule: Nucleic Acids Monomer: Function: • Information storage Phosphate Examples: • DNA Sugar Base • RNA Could this be a monomer for RNA?

  48. Chapter 3: The Molecules of Life Activities Quiz http://wps.aw.com/bc_campbell_essentials_3/0,11844,3107816-,00.html Which of these is a source of lactose? Sugar beets milk potatoes sugar cane starch If a DNA double helix is 100 nucleotide pairs long and contains 25 adenine bases, how many guanine bases does it contain? 150, 75, 50, 200 25,

  49. Which of these is a polysaccharide? Sucrose, glucose, galactose, lactose, cellulose Defensive proteins are manufactured by the _____ system. Immune, nervous, digestive, integumentary, cardiovascular Which of these illustrates the secondary structure of a protein? A B C D E