Chapter2 part2
- 1. Molecules of Life Chapter 2 Part 2
- 2. 2.6 Organic Molecules The molecules of life – carbohydrates, proteins, lipids, and nucleic acids – are organic molecules Organic Type of molecule that consists primarily of carbon and hydrogen atoms
- 4. Modeling an Organic Molecule
- 5. Building Organic Molecules Carbon atoms bond covalently with up to four other atoms, often forming long chains or rings Enzyme-driven reactions construct large molecules from smaller subunits, and break large molecules into smaller ones
- 6. From Structure to Function Cells assemble large polymers from smaller monomers, and break apart polymers into component monomers Metabolism All the enzyme-mediated chemical reactions by which cells acquire and use energy as they build and break down organic molecules
- 7. Monomers and Polymers Monomers Molecules that are subunits of polymers Simple sugars, fatty acids, amino acids, nucleotides Polymers Molecules that consist of multiple monomers Carbohydrates, lipids, proteins, nucleic acids
- 8. Condensation and Hydrolysis Condensation (water forms) Process by which an enzyme builds large molecules from smaller subunits Hydrolysis (water is used) Process by which an enzyme breaks a molecule into smaller subunits by attaching a hydroxyl to one part and a hydrogen atom to the other
- 10. Animation: Condensation and hydrolysis
- 12. 2.7 Carbohydrates Cells use carbohydrates for energy and structural materials Carbohydrates Molecules that consist primarily of carbon, hydrogen, and oxygen atoms in a 1:2:1 ratio
- 13. Complex Carbohydrates Enzymes assemble complex carbohydrates (polysaccharides) from simple carbohydrate (sugar) subunits Glucose monomers can bond in different patterns to form different complex carbohydrates Cellulose (a structural component of plants) Starch (main energy reserve in plants) Glycogen (energy reserve in animals)
- 15. Fig. 2-13 (center), p. 31
- 16. Fig. 2-13a, p. 31
- 17. Fig. 2-13b, p. 31
- 18. Fig. 2-13c, p. 31
- 19. Animation: Structure of starch and cellulose
- 20. Animation: Examples of monosaccharides
- 21. 2.8 Lipids Lipids are greasy or oily nonpolar organic molecules, often with one or more fatty acid tails Lipids Fatty, oily, or waxy organic compounds Fatty acid Consists of a long chain of carbon atoms with an acidic carboxyl group at one end
- 22. Fats Fats, such as triglycerides, are the most abundant source of energy in vertebrates – stored in adipose tissue that insulates the body Fat Lipid with one, two, or three fatty acid tails Triglyceride Lipid with three fatty acid tails attached to a glycerol backbone
- 23. Saturated and Unsaturated Fats Saturated fats pack more tightly than unsaturated fats, and tend to be more solid Saturated fat Fatty acid with no double bonds in its carbon tail Unsaturated fat Lipid with one or more double bonds in a fatty acid tail
- 24. Fatty Acids Saturated, unsaturated, cis , and trans fatty acids
- 25. Fig. 2-14, p. 32 carboxyl group long carbon chain cis double bond trans double bond A stearic acid B linolenic acid C oleic acid D elaidic acid
- 26. Phospholipids Phospholipids are the main structural component of cell membranes Phospholipid A lipid with a phosphate group in its hydrophilic head, and two nonpolar fatty acid tails
- 27. Phospholipids
- 28. Fig. 2-15, p. 32 hydrophilic head two hydrophobic tails A one layer of lipids one layer of lipids B a lipid bilayer
- 29. Fig. 2-15b, p. 32 one layer of lipids one layer of lipids B a lipid bilayer
- 30. Waxes Waxes are part of water-repellent and lubricating secretions in plants and animals Wax Water-repellent lipid with long fatty-acid tails bonded to long-chain alcohols or carbon rings
- 31. Steroids Steroids such as cholesterol occur in cell membranes or are remodeled into other molecules (such as steroid hormones, bile salts, and vitamin D) Steroid A type of lipid with four carbon rings and no fatty acid tails
- 32. Steroids
- 37. 2.9 Proteins A protein’s function depends on its structure, which consists of chains of amino acids that twist and fold into functional domains Protein Organic compound that consists of one or more chains of amino acids
- 38. Amino Acid Amino acid Small organic compound with a carboxyl group, amine group, and a characteristic side group (R)
- 39. Peptide Bonds Amino acids are linked into chains by peptide bonds Peptide bond A bond between the amine group of one amino acid and the carboxyl group of another Polypeptide Chain of amino acids linked by peptide bonds
- 41. Fig. 2-17, p. 34 methionine methionine —serine serine
- 42. Animation: Peptide bond formation
- 43. Protein Synthesis 1. Primary structure (polypeptide formation) A linear sequence of amino acids 2. Secondary structure Hydrogen bonds twist the polypeptide into a coil or sheet 3. Tertiary structure Secondary structure folds into a functional shape
- 44. Protein Synthesis 4. Quaternary structure In some proteins, two or more polypeptide chains associate and function as one molecule Example: hemoglobin 5. Fibrous proteins may aggregate into a larger structure, such as keratin filaments Example: hair
- 46. Fig. 2-18, p. 35 lysine glycine glycine arginine 1 2 3 4 5
- 47. Fig. 2-18, p. 35 Stepped Art 5 5) Many proteins aggregate by the thousands into larger structures, such as the keratin filaments that make up hair. 2 2) Secondary structure arises when a polypeptide chain twists into a coil (helix) or sheet held in place by hydrogen bonds between different parts of the molecule. The same patterns of secondary structure occur in many different proteins. 3 3) Tertiary structure occurs when a chain’s coils and sheets fold up into a functional domain such as a barrel or pocket. In this example, the coils of a globin chain form a pocket. 4 4) Some proteins have quaternary structure, in which two or more polypeptide chains associate as one molecule. Hemoglobin, shown here, consists of four globin chains (green and blue). Each globin pocket now holds a heme group (red). lysine glycine glycine arginine 1 1) A protein’s primary structure consists of a linear sequence of amino acids (a polypeptide chain).
- 48. Animation: Secondary and tertiary structure
- 49. The Importance of Protein Structure Changes in a protein’s structure may also alter its function Denature To unravel the shape of a protein or other large biological molecule
- 50. Misfolded Proteins: Prion Disease Prion A misfolded protein that becomes infectious Example: mad cow disease (BSE) in cattle Example: vCJD in humans
- 51. Variant Creutzfeldt-Jakob Disease (vCJD)
- 52. Fig. 2-19a, p. 36
- 53. Fig. 2-19a, p. 36 Conformational change ? PrP C protein prion protein
- 54. Animation: Structure of an amino acid
- 55. Animation: Molecular models of the protein hemoglobin
- 56. Animation: Globin and hemoglobin structure
- 57. 2.10 Nucleic Acids Nucleotide Monomer of nucleic acids Has a five-carbon sugar, a nitrogen-containing base, and phosphate groups Nucleic acids Polymers of nucleotide monomers joined by sugar-phosphate bonds (include DNA, RNA, coenzymes, energy carriers, messengers)
- 58. ATP The nucleotide ATP can transfer a phosphate group and energy to other molecules, and is important in metabolism Adenosine triphosphate (ATP) Nucleotide that consists of an adenine base, five-carbon ribose sugar, and three phosphate groups Functions as an energy carrier
- 59. Functions of DNA and RNA DNA encodes heritable information about a cell’s proteins and RNAs Different RNAs interact with DNA and with one another to carry out protein synthesis
- 60. DNA and RNA Deoxyribonucleic acid (DNA) Nucleic acid that carries hereditary material Two nucleotide chains twisted in a double helix Ribonucleic acid (RNA) Typically single-stranded nucleic acid Functions in protein synthesis
- 61. A Nucleotide and Nucleic Acid
- 62. Fig. 2-20a, p. 37
- 63. Fig. 2-20a, p. 37 3 phosphate groups base: adenine (A) sugar: ribose
- 64. Fig. 2-20b, p. 37
- 65. Animation: Structure of ATP
- 66. Animation: Subunits of DNA
- 67. 2.11 Impacts/Issues Revisited Our enzymes can’t easily break down trans fats in processed foods, which causes health problems – several countries will not import foods made in the US that contain trans fats
- 68. Digging Into Data: Effects of Fats on Lipoprotein Levels
- 69. Fig. 2-21, p. 39 protein lipid Main Dietary Fats cis -fatty acids trans -fatty acids saturated fats optimal level an HDL particle LDL 103 117 121 <100 HDL 55 48 55 >40 ratio 1.87 2.44 2.2 <2
Editor's Notes
- #16: Figure 2.13 Three of the most common complex carbohydrates and their locations in a few organisms. Each polysaccharide consists only of glucose units, but different bonding patterns that link the subunits result in substances with very different properties.
- #17: Figure 2.13 Three of the most common complex carbohydrates and their locations in a few organisms. Each polysaccharide consists only of glucose units, but different bonding patterns that link the subunits result in substances with very different properties.
- #18: Figure 2.13 Three of the most common complex carbohydrates and their locations in a few organisms. Each polysaccharide consists only of glucose units, but different bonding patterns that link the subunits result in substances with very different properties.
- #19: Figure 2.13 Three of the most common complex carbohydrates and their locations in a few organisms. Each polysaccharide consists only of glucose units, but different bonding patterns that link the subunits result in substances with very different properties.
- #26: Figure 2.14 Fatty acids. (A) The backbone of stearic acid is fully saturated with hydrogen atoms. (B) The backbone of linolenic acid, with three double bonds, is unsaturated. The first double bond occurs at the third carbon from the end, so linoleic acid is called an omega-3 fatty acid. Omega-3 and omega-6 fatty acids are “essential fatty acids.” Your body does not make them, so they must come from food. The only difference between oleic acid (C) , a cis fatty acid, and elaidic acid (D) , a trans fatty acid, is the arrangement of hydrogens around the one double bond in the backbone.
- #29: Figure 2.15 Phospholipids. (A) Each phospholipid has a hydrophilic head and two hydrophobic tails. (B) A double layer of phospholipids is the structural foundation of all cell membranes.
- #30: Figure 2.15 Phospholipids. (A) Each phospholipid has a hydrophilic head and two hydrophobic tails. (B) A double layer of phospholipids is the structural foundation of all cell membranes.
- #42: Figure 2.17 : Animated! Polypeptide formation. Chapter 7 returns to protein synthesis. (A) Two amino acids (here, methionine and serine) are joined by condensation. A peptide bond forms between the carboxyl group of the methionine and the amine group of the serine. (B) Peptide bonds join additional amino acids to the carboxyl end of the chain. The resulting polypeptide can be thousands of amino acids long.
- #47: Figure 2.18 : Animated! Protein structure. 1 A protein’s primary structure consists of a linear sequence of amino acids (a polypeptide chain). 2 Secondary structure arises when a polypeptide chain twists into a coil (helix) or sheet held in place by hydrogen bonds between different parts of the molecule. The same patterns of secondary structure occur in many different proteins. 3 Tertiary structure occurs when a chain’s coils and sheets fold up into a functional domain such as a barrel or pocket. In this example, the coils of a globin chain form a pocket. 4 Some proteins have quaternary structure, in which two or more polypeptide chains associate as one molecule. Hemoglobin, shown here, consists of four globin chains ( green and blue ). Each globin pocket now holds a heme group ( red ). 5 Many proteins aggregate by the thousands into larger structures, such as the keratin filaments that make up hair.
- #48: Figure 2.18 : Animated! Protein structure. 1 A protein’s primary structure consists of a linear sequence of amino acids (a polypeptide chain). 2 Secondary structure arises when a polypeptide chain twists into a coil (helix) or sheet held in place by hydrogen bonds between different parts of the molecule. The same patterns of secondary structure occur in many different proteins. 3 Tertiary structure occurs when a chain’s coils and sheets fold up into a functional domain such as a barrel or pocket. In this example, the coils of a globin chain form a pocket. 4 Some proteins have quaternary structure, in which two or more polypeptide chains associate as one molecule. Hemoglobin, shown here, consists of four globin chains ( green and blue ). Each globin pocket now holds a heme group ( red ). 5 Many proteins aggregate by the thousands into larger structures, such as the keratin filaments that make up hair.
- #53: Figure 2.19 Variant Creutzfeldt–Jakob disease (vCJD). (A) The PrPC protein becomes a prion when it misfolds into an as-yet unknown conformation. Prions cause other PrPC proteins to misfold, and the misfolded proteins aggregate into long fibers. (B) Slice of brain tissue from a person with vCJD. Characteristic holes and prion protein fibers radiating from several deposits are visible. (C) Charlene Singh, here being cared for by her mother, was one of three people who developed symptoms of the disease while living in the United States. Like the others, Singh most likely contracted the disease elsewhere; she spent her childhood in Britain. She was diagnosed in 2001, and she died in 2004.
- #54: Figure 2.19 Variant Creutzfeldt–Jakob disease (vCJD). (A) The PrPC protein becomes a prion when it misfolds into an as-yet unknown conformation. Prions cause other PrPC proteins to misfold, and the misfolded proteins aggregate into long fibers. (B) Slice of brain tissue from a person with vCJD. Characteristic holes and prion protein fibers radiating from several deposits are visible. (C) Charlene Singh, here being cared for by her mother, was one of three people who developed symptoms of the disease while living in the United States. Like the others, Singh most likely contracted the disease elsewhere; she spent her childhood in Britain. She was diagnosed in 2001, and she died in 2004.
- #63: Figure 2.20 : Animated! A nucleotide and a nucleic acid. (A) The nucleotide ATP. (B) DNA consists of two chains of nucleotides, twisted into a double helix held together by hydrogen bonds.
- #64: Figure 2.20 : Animated! A nucleotide and a nucleic acid. (A) The nucleotide ATP. (B) DNA consists of two chains of nucleotides, twisted into a double helix held together by hydrogen bonds.
- #65: Figure 2.20 : Animated! A nucleotide and a nucleic acid. (A) The nucleotide ATP. (B) DNA consists of two chains of nucleotides, twisted into a double helix held together by hydrogen bonds.
- #70: Figure 2.21 Effect of diet on lipoprotein levels. Researchers placed 59 men and women on a diet in which 10 percent of their daily energy intake consisted of cis fatty acids, trans fatty acids, or saturated fats. Blood LDL and HDL levels were measured after three weeks on the diet; averaged results are shown in mg/dL (milligrams per deciliter of blood). All subjects were tested on each of the diets. The ratio of LDL to HDL is also shown.