Thursday 11/21/13 - PowerPoint PPT Presentation

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Thursday 11/21/13
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Thursday 11/21/13

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  1. Thursday 11/21/13 • AIM: Why do we eat proteins • DO NOW: What are biomolecules? Why are biomolecules organic compounds? • HW:Read page 62. reading check on page 62 and question 4 on page 63

  2. Review What are the 4 categories of biomolecules? • Why are biomolecules called polymers? • How do you build polymers? • How do you break down polymers?

  3. Synthesis of polymers Monomers form larger molecules by condensation reactions called dehydration reactions 1 HO H 3 2 H HO Unlinked monomer Short polymer Dehydration removes a watermolecule, forming a new bond H2O 1 2 3 4 HO H Longer polymer (a) Dehydration reaction in the synthesis of a polymer Figure 5.2A

  4. The Breakdown of Polymers Hydrolysis 1 3 HO 4 2 H Hydrolysis adds a watermolecule, breaking a bond H2O 1 2 H HO 3 H HO (b) Hydrolysis of a polymer Figure 5.2B

  5. Which biomolecules can be found in the food sources below?

  6. Protein Carbon, Hydrogen, oxygen, nitrogen, sulfur Structure for tissues and organs Hormones Metabolism Transport Receptors Catalysts

  7. Structural Support • Collagen and elastin

  8. Hormones: chemical messengers • Human Growth Hormone, Insulin, Glucagon

  9. Transport across the cell membrane • In and out of cell

  10. Transport through the body • Hemoglobin

  11. Receptors

  12. Enzymes are protein catalysts

  13. How do we build large proteins?

  14. How are amino acids related to proteins?

  15. Friday 11/22/13 • DO NOW: • Motivation: draw an amino acid using the following colors

  16. Amino Acid • All amino acids have the same fundamental structure • The R group gives the amino acid it’s unique properties • Size, water solubility, electrical charge

  17. There are only 20 amino acids which account for all of the proteins in all organisms

  18. Proteins Polymers made of subunits called amino acids Amino acids: form 1 or more chains which fold extensively to form a functional protein

  19. Dehydration synthesis of amino acids forms peptide bonds Protein or polypeptide: 50 or more amino acids bonded togetherPeptide: shorter chains

  20. Shape of protein correlates to it’s function Shape of protein is determined by exact type, position and number of it’s amino acids In many cases 2 or more amino acid chains join Amino acid chain undergoes a series of folds If the shape of protein is denatured, the protein may no longer be able to function properly

  21. ProteinsProtein structure ProteinsProtein structure Primary structure Proteins • Primary structure: Polypeptide chain

  22. ProteinsProtein structure Secondary structure Secondary structure: folding of polypeptide chain

  23. ProteinsProtein structure Tertiary structure Tertiary structure • Disulfide bridges

  24. ProteinsProtein structure Quaternary structure Quaternary structure • Functional protein

  25. Hemoglobin protein

  26. Protein Structure

  27. Assessment • Create a table listing and describing each step in the development of a functional protein

  28. Monday • AIM: How do enzymes catalyze metabolic reactions? • DO NOW: Use your notes to draw and label the structure of an amino acid

  29. Enzymes are proteins • Built from amino acids

  30. Enzymes are catalysts

  31. Enzymes are organic catalysts Speed up chemical reactions without being consumed by the reaction Proteins Built from amino acids Lower activation energy: the amount of energy needed for a chemical reaction to occur

  32. Naming enzymes Enzyme names end with the -ase suffix, the -ase suffix is added to the substrate name. For example, sucrase is the enzyme that breaks down the substrate sucrose, a disaccharide, into the monosaccharides glucose and fructose. Protease: the enzyme that catalyzes the break down of proteins into amino acids

  33. AIM: why are enzymes protein catalysts? • DO NOW: What type of molecule are enzymes?

  34. How Do Enzymes Work?

  35. How do enzymes work? Enzymes are substrate specific Substrate is the reactant Active site: part of the enzyme capable of recognizing and binding to substrate

  36. 2 methods in which enzymes work • Induced Fit Model • Lock and key model

  37. Induced fit model Actually the "fit" of the substrate and the active site is not a "perfect fit” enzyme slightly changes shape to fit the substrate

  38. Lock and key model • Active site of the enzyme fits perfectly to only one type of substrate

  39. Enzyme-substrate complex • Lowers the activation energy causing the chemical reaction to happen

  40. Assessment • In one complete sentence,explain why the shape of enzyme is important to its function.

  41. AIM: What factors effect the rate of enzyme activity? • DO NOW: What is activation energy? • Enzyme Quiz Monday

  42. DO NOW Answer • Activation energy: The amount of energy it takes for a chemical reaction to occur • How do enzymes catalyze chemical reactions? • By lowering the activation energy • When do enzymes lower activation energy? • Enzyme substrate complex

  43. At the enzyme substrate complex

  44. Factors that affect enzyme activity 1. Amount of enzyme 2. Amount of substrate 3. pH 4. Temperature

  45. Concentration of Enzyme If the amount of substrate remains the same: As increase amount of enzyme, the rate of an enzyme action also increase UNTIL… All enzymes become saturated At this point all enzymes are working at maximum capacity

  46. Concentration of substrate If the amount of enzyme remains the same: at low concentrations, of substrate, Enzyme activity is low Because all enzymes are NOT working As you increase the amount of substrate, you increase enzyme activity until all substrates are bound to enzymes At this point, enzymeactivity is steady

  47. pH Each enzyme works best at a certain pH 2. At optimal (best) pH: enzyme has the right shape to fit substrate 3. Changes in pH change the shape of enzymes and their ability to fit with substrates 4. Most enzymes work best at pH’s near 7 (neutral)