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Essential Knowledge 4.A.1

Essential Knowledge 4.A.1

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Essential Knowledge 4.A.1

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  1. Essential Knowledge 4.A.1 • The subcomponents of biological molecules and their sequence determine the properties of that molecule • a. Structure and function of polymers are derived from the way their monomers are assembled • b.

  2. Organic Molecules • Carbon—The Backbone of Biological Molecules • All living organisms • Are made up of chemicals based mostly on the element carbon

  3. Organic chemistry is the study of carbon compounds, chemistry of organisms • Organic compounds range from simple molecules to very large ones

  4. Carbon atoms can form diverse molecules by bonding to four other atoms • Life’s molecular diversity is based on Carbon’s properties

  5. The Formation of Bonds with Carbon • Carbon has four valence electrons • This allows it to form four covalent bonds with a variety of atoms • The bonding versatility of carbon

  6. Molecular Diversity Arising from Carbon Skeleton Variation • Carbon chains • Form the skeletons of most organic molecules

  7. Hydrocarbons • Hydrocarbons • Are chains of carbon bonded only to hydrogen

  8. Hydrocarbons • Are found in many of a cell’s organic molecules

  9. Isomers • Isomers • Are molecules with the same molecular formula but different structures and properties

  10. Functional Groups • Functional groups are the parts of molecules involved in chemical reactions, they have a specific combination of atoms that always react in the same way • The unique properties of organic compounds depend on the functional groups attached to the carbon skeleton

  11. Functional groups give organic molecules distinctive chemical properties

  12. The Functional Groups Most Important in the Chemistry of Life • Four functional groups are important in the chemistry of life • Hydroxyl • Carbonyl • Carboxyl • Amino

  13. Sugars contain a hydroxyl and carbonyl group, making them alcohols and ketones • These functional groups are polar (because of nitrogen and oxygen), thus making compounds with them hydrophilic or water soluble

  14. R R SH OH O O R R C C OH H O R R C H R N H O R-O OH P OH Biologically ImportantFunctional Groups • Group • Structure • Compound • Significance • Alcohols • Hydroxyl • Polar, forms H-bonds; some sugarsand amino acids Example: Ethanol • Aldehydes • Polar; some sugarsExample: Formaldehyde • Carbonyl • Ketones • Polar; some sugarsExample: Acetone • CarboxylicAcids • Polar, acidic; fats and amino acidsExample: Acetic acid • Carboxyl • Amines • Polar, basic; amino acidsExample: Tryptophan • Amino • Thiols • Sulfhydryl • Disulfide Bonds; some amino acidsExample: Ethanethiol • OrganicPhosphates • Polar, acidic; some amino acidsExample: Adenosine triphosphate • Phosphate

  15. Macromolecules • Are very large molecules

  16. Three of the classes of life’s organic molecules are polymers • Carbohydrates • Proteins • Nucleic acids

  17. The Synthesis and Breakdown of Polymers • Monomers form larger molecules by condensation reactions called dehydration reactions

  18. Polymerscan disassemble by • Hydrolysis (digestion)

  19. The Diversity of Polymers • Each class of polymer • Is formed from a specific set of monomers • Nucleic acids are formed by monomers called nucleotides • Carbohydrates are built from monosaccharides 1 3 2 H HO

  20. Although organisms share the same limited number of monomer types, each organism is unique based on the arrangement of monomers into polymers

  21. Trillions of different proteins are constructed from only 20 different amino acids linked into chains several hundred long

  22. Carbohydrates • Carbohydrates serve as fuel and building material • Polymers constructed from monomers which are monosaccharides

  23. Sugars • Monosaccharides • Are the simplest sugars • Main source of fuel for cells • Can be combined into polymers • Molecular formulas are multiples of CH2O (C:H:O ratio = 1:2:1) • Trademarks of sugars: hydroxl group andcarbonyl

  24. Hexoses - 6 carbon sugars • Glucose • Fructose • Galactose • Pentoses - five carbon sugars • Ribose • Deoxyribose

  25. Monosaccharides • May be linear • Can formrings (happens in aqueous solutions) • Can switch back and forth between linear and rings

  26. Disaccharides - double sugar • Consist of two monosaccharides • Types: • Sucrose = glucose + fructose • Maltose = glucose + glucose • Lactose = glucose + galactose

  27. Polysaccharides • Polysaccharides • Are polymers of sugars (from a few hundred to a few thousand linked monosaccharides) • Serve many roles in organisms

  28. Storage Polysaccharides • Starch • Is a polymer consisting entirely of glucose monomers • Stored in plants as starch granules in cells • Broken down (hydrolyzed) into glucose to provide energy or building blocks for other molecules

  29. Storage Polysaccharides STARCH is the major storage form of glucose in plants

  30. Storage Polysaccharides • Glycogen • Consists of glucose monomers • Is the major storage form of glucose in animals • Stored in liver and muscle cells

  31. Structural Polysaccharides • Cellulose • Is a polymer of glucose • Most abundant organic compound found on Earth • Not digestible like starch or glycogen

  32. Cellulose • Is a major component of the tough walls that enclose plant cells

  33. Cellulose is difficult to digest • Cows, termites have microbes in their stomachs to facilitate this process

  34. Cellulose • Has different glycosidic linkages than starch

  35. Glucose-numbered carbon atoms

  36. The main structural difference comes from the difference in the sequence of bonds in glycogen and cellulose and starch where the three of them composed mainly of glucose and its derivatives. • Starch, glycogen and cellulose are all polymers of glucose.

  37. Starch and glycogen are made from alpha-glucose. This is an isomer of glucose in which the hydroxyl (-OH) group attached to carbon number 1 is below the plane of the ring. • Starch is itself composed of two types of polymer: amylose and amylopectin. In amylose, the glucose monomers are linked by 1,4 glycosidic bonds. This means that the bond connects carbon atom number 1 in one glucose to carbon atom number 4 in the other glucose.

  38. In amylopectin there are two types of glycosidic bonds: 1,4 and 1,6. Some glucose molecules have a glycosidic link from carbon atom number 6 to carbon atom number 1 in a new glucose molecule. This produces a branch point in the amylopectin molecule. • .

  39. Glycogen • Cellulose is an unbranched polymer composed of beta glucose molecules. Beta glucose is an isomer of glucose in which the hydroxyl group attached to carbon 1 is above the plane of the ring. The glucose monomers are linked by 1,4 glycosidic bonds.

  40. Structural Polysaccharides • Chitin, another important structural polysaccharide containing nitrogen • Is found in the exoskeleton of arthropods, cell walls in fungi

  41. Peptidoglycan Polysaccharide found in bacterial cell walls (D.Bacteria) Contains glucose monomers with attached amino acids

  42. Lipids • Lipids are a diverse group of hydrophobic molecules, composed mostly of carbon and hydrogen linked in non-polar covalent bonds • Lipids • Share the common trait of being hydrophobic - they are not attracted to water molecules and are non-soluble in water (oil and water)

  43. Lipids • Insoluble in water • Long chains of repeating CH2 units • Renders molecule nonpolar • Types of Lipids • Type • Organismal Uses • Human Uses • Fats • Long-term energy storage & thermal insulation in animals • Butter, lard • Oils • Long-term energy storage in plants and their seeds • Cooking oils • Phospholipids • Component of plasma membrane • No-stick pan spray • Steroids • Component of plasma membrane; hormones • Medicines • Waxes • Wear resistance; retain water • Candles, polishes

  44. Fats-triglycerides • Fats are constructed from two types of smaller molecules, a single glycerol and usually three fatty acids (oils are types of fats)

  45. Fatty acids • Vary in the length and number and locations of double bonds they contain

  46. Saturated fatty acids • Have the maximum number of hydrogen atoms possible

  47. Saturated fatty acids • Are solid at room temperature (butter, lard) • Bad fats - may be linked to cardiovascular disease by promoting atherosclerosis (plaque buildup in vessels)

  48. Unsaturated fatty acids • Have one or more double bonds

  49. Unsaturated Fatty Acids • Less than the maximum number of hydrogen atoms due to double bonds • Plant fats are unsaturated oils • Corn, vegetable, olive oils • Good fats

  50. Phospholipids • Phospholipids • Have only two fatty acids (hydrophobic tail) • Have a phosphate group instead of a third fatty acid (hydrophilic head)