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Macromolecules

Macromolecules. Organic compounds Contain both hydrogen and carbon Large molecules composed of smaller subunits Carbohydrates Proteins Lipids Nucleic Acids . Carbohydrates (Sugars). Bio-molecule consisting of carbon, oxygen, and hydrogen.

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Macromolecules

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  1. Macromolecules • Organic compounds • Contain both hydrogen and carbon • Large molecules composed of smaller subunits • Carbohydrates • Proteins • Lipids • Nucleic Acids

  2. Carbohydrates (Sugars) • Bio-molecule consisting of carbon, oxygen, and hydrogen. • General molecular formula (CnH₂nOn) (C₆H₁₂O₆) • Roles • Energy storage - plants • Structural support in cells and tissues • Hydrophilic • Pentose/Hexose ring structure

  3. Monosaccharides • Simplest type of carbohydrate • Used as primary energy source for cellular metabolism (making ATP) • 1 sugar unit • Glucose – grape sugar, blood sugar • Fructose – honey, fruit juices

  4. Monosaccharides • Most Common • 3 carbon (linear) – triose • 5 carbon – pentose ring • 6 carbon – hexose ring • Why? • Folding into a ring occurs through a reaction between carbonyl group and hydroxy l group • Link together to form disaccharides

  5. Glucose • Linear and ring structures • Hexose ring • Two possible arrangements • α - glucose • Β – glucose • Isomers – same molecular formula, different structural formula • Carbon atoms have assigned numbers • Used when discussing structures of sugars Linkages are designated α or β from the position of the –OH group on the 1 carbon

  6. Disaccharides • Consist of two monosaccharides • Maltose – used to make beer • Sucrose – simple sugar found in plant sap • Lactose – milk • Used as energy sources and building blocks for larger molecules • Joined together by a dehydration synthesis reaction • Glycosidic bond – links monosaccharides together • Common carbon linkages • 1 4 1 2 • 1 3 1 6

  7. Polysaccharides • Complex carbohydrate/polymer • Chain of hundreds to thousands of monosaccharides (monomers) with many subunits • Unbranched – single chain • Branched – side chains

  8. Polysaccharides • Assembled by dehydration reaction • Glycosidic linkage • Polymerization – linkage of identical or various monomers to form long chains • Linear unbranched • hydrogen bonds form between molecules • Polar • Hydrophilic • Non-soluble in water

  9. Examples • Amylose – soluble component of starch • Glycogen – energy storage in animals • Cellulose – main component of plant cell walls • Chitin – hard exoskeleton of insect and crustaceans

  10. Lipids • Non-polar • Made up of mostly carbon and hydrogen • Not polymers • Do not dissolve in water • Roles • Formation of cell membranes • Energy source • Hormones • Vitamins • 5 main categories • Fatty acids • Fats • Phospholipids • Steroids • Waxes

  11. Fatty Acids • Derivative of most lipids (structural backbone) • Consists of • Single hydrocarbon chain (14 to 22) • Carboxyl functional group at one end (-COOH) • Gives the fatty acid its acidic properties • As chain length increases, insolubility in water increases

  12. Fatty Acids • Saturated • Max number of hydrogen atoms attached to carbons • Single bonds throughout the carbon chain • Solid at room temp • Unsaturated • Formation of double bonds in carbon chain • Monounsaturated – one double bond • Polyunsaturated – many double bonds • Causes a bent formation in molecule • Liquid at room temp

  13. Fats • Consists of • 1 to 3 fatty acid chains • Glycerol • Dehydration synthesis • Hydroxyl group of glycerol and carboxyl group of fatty acid • Can have identical/different fatty acid chains • Hydrophobic

  14. Triglycerides • Most well known fat • Contains 3 fatty acid chains • Stored energy (food) in fat cells • Liver produces triglycerides • Yield more than twice as much energy as carbohydrates • Normal blood level – less than 150 mg/dL

  15. Phospholipids • Consists of • 2 fatty acid chains (hydrophobic) • Glycerol • Phosphate group • contains a polar unit (hydrophilic) • Amphipathic • Contains both hydrophobic and hydrophilic regions

  16. Phospholipids • Roles • Lipid bilayer of cell membranes • Hydrophilic end faces toward water • Hydrophobic end faces inward • Unsaturated tail makes membrane more permeable to water and small molecules

  17. Steroids • Consists of • Four fused carbon ring • Side group • Sterols • Most abundant • Consists of • Single polar –OH group • Non – polar hydrocarbon chain • Amphipathic molecule • Eg; Cholesterol , Phytosterols

  18. Cholesterol • Formed in the liver • Structural component of plasma membrane (nearly half) • Amphipathic • Function • Maintains integrity of membrane • Proper membrane permeability/fluidity

  19. Cholesterol • Can’t dissolve in blood • Transported by carriers • Types • LDL – low density lipoprotein • Promote cardiovascular disease • HDL – high density lipoprotein • Good cholesterol • removes cholesterol from artery • Eliminated in liver

  20. Sex Hormones • Control development of sexual traits and sex cells • Eg; testosterone, estrogen, progesterone

  21. Waxes • Consist of • Long fatty acid chains • Alcohol molecule or Carbon ring • Hydrophobic • Extremely non-polar • Soft Solids • Functions • Waterproof coating on various plant and animal parts • Cutin – plants conserve water and fights disease • Beeswax – production of honeycomb

  22. Proteins • Polymer with many subunits • Composed of Amino Acids (monomers) • Folded into a 3-D structure • Primary Secondary • Tertiary Quaternary • Folding allows protein to function • Structure specifies function of protein • Formed by dehydration reaction • Peptide bonds link amino acids together

  23. Amino Acids • 20 different amino acids • 8 essential - supplied by diet • Contain: • Central carbon • Amino group (-NH₂) • Carboxyl group (-COOH) • R group • R groups give each amino acids specific characteristics • Polarity, acidity

  24. Amino Acids

  25. Peptide Bond • Covalent bond between (NH₂) group of one amino acid and (COOH) group of another. • Amino acids are only added to the C-terminal of a growing peptide • Peptide • String of 1-49 amino acids • Contains no side branches • Polypeptide • String of 50 or more amino acids

  26. Proteins • Structural – framework support (hair, tendon, ligaments) • Defensive – infection fighters (antibodies) • Signal – messenger (hormones) • Carrier – transport of materials (hemoglobin) • Recognition and Receptor – cellular markers (major histocompatability complex) • Enzyme – catalyst (amylase) • Motile – movement (actin and myosin)

  27. Protein Structure • Primary Structure 1⁰ • Linear sequence of amino acids in polypeptide chain • Changing one amino acid with change overall structure of protein

  28. Protein Structure • Secondary Structure • Polypeptides fold or coil into patterns • Result of hydrogen bonding • β-pleated sheets • Side-by-side alignment • (Eg; strength of silk) • α-helix • Coil that is held together by hydrogen bonds between every 4th amino acid • (Eg; filamentous proteins, transmembrane proteins)

  29. Protein Structure • Tertiary Structure 3⁰ • 3-D shape of a protein • Intermolecular reactions of amino acid R groups determines shape • Include • Ionic bonds • Hydrogen bonds • Hydrophobic interactions • Non-polar side groups cluster when introduced to water • Disulfide bridges • Bond formed from two cysteine amino acids (-SH group) • Stabilizes proteins shape

  30. Protein Structure • Quaternary Structure 4⁰ • Composed of 2 or more polypeptides • Functional proteins • Forms subunits • Same bonds and forces as tertiary structure

  31. Protein Prosthetic Groups • Non-protein components • Metal ions (Fe²⁺ Mg²⁺) • Needed for protein to function • Hemoglobin • 4 polypetide chains each with a heme groups • Each group has a single iron ion (Fe²⁺) • Oxygen binds to heme groups via (Fe²⁺) • How many molecules of O₂ can hemoglobin carry at one time?

  32. Protein Denaturation • When a protein loses its 3-D structure • Often irreversible • Extreme temperatures • pH • Chemcials

  33. Nucleic Acids • Polynucleotide chains serve as assembly instructions for all proteins in living organisms • DNA – deoxyribonucleic acid • Stores hereditary information • RNA – Ribonucleic acid • Hereditary molecule of some viruses • Involved in protein synthesis • Composed of nucleotides • Linked by a phosphodiester bond

  34. Nucleotides • Consists of • Nitrogenous base • Uracil (U), thymine (T), cytosine (C), adenine (A), guanine (G) • Sugar • Phosphate groups • Functions • Transport chemical energy • Regulate and adjust cellular activity

  35. Nitrogenous Bases • 2 types • Pyrimidines • Uracil (U), Thymine (T), Cytosine (C) • Purines • Adenine (A), Guanine (G)

  36. Phosphodiester Bond • Links nucleotides together • Phosphate bridge forms between the 5’ carbon of one sugar and the 3’ carbon of the next sugar. • Forms the backbone of a nucleic acid chain • Nitrogenous bases project from the backbone

  37. DNA • Consists of • Deoxyribose sugar • Phosphate group • A, T, C, G • Double stranded molecule (Double Helix) • Two strands of DNA run antiparallel to each other (opposite direction) • 5’ to 3’ • 5’ is the end with the phosphate group • 3’ is where deoxyribose sugar is located • Nitrogenous bases • Held together by hydrogen bonds • A pairs with T ( forms double bond) • C pairs with G (forms a triple bond)

  38. RNA • Consists of • Ribose sugar • Phosphate group • A, U, C, G • Single stranded molecule • Converts information stored in DNA into proteins

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