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Macromolecules

Macromolecules. Standard Qualitative Tests and Testing Your Own Food. Qualitative. Detecting if a substance is present You don’t know how much. SAFETY. IF A SOLID, cut into little pieces Rinse razor blades under water , do not wipe across the blade

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Macromolecules

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  1. Macromolecules Standard Qualitative Tests and Testing Your Own Food

  2. Qualitative • Detecting if a substance is present • You don’t know how much

  3. SAFETY • IF A SOLID, cut into little pieces • Rinse razor blades under water, do not wipe across the blade • Put used blades at the end of the period in the “used beaker” on the cart

  4. Goggles and Apron • Chemicals are caustic to your eyes • Iodine stains

  5. Dropper Full Just squeeze to fill dropper and release Exact amounts are not important 1 dropper full = 20-30 drops When it asks for…

  6. Pasteur Pipets

  7. NEVER, hold a filled pipet upside down…or hold on its side… You contaminate the bulb NEVER EVER

  8. For 5mL and 10 mL • ACID • SUCROSE

  9. Positive Control Absolutely expect to see the result Use the substance (starch, glucose, etc.) Negative Control Absolutely expect to NOT see the result (may use water) Controls

  10. Lab Objective: • Describe the test that indicates the presence of most small sugars.

  11. Recording Benedict’s Results • - blue no sugar • + blue/green trace • ++ green little sugar • +++ yellow some sugar • ++++ orange/red much sugar

  12. Benedict’s Sugar Test

  13. Lab Objectives: • Describe the test that indicates the presence of starch. • IODINE IS POISONOUS!!!

  14. Iodine Test negative positive

  15. Lab Objective: • Define hydrolysis and give an example of the hydrolysis of carbohydrates. • ANIMATION LINKS:Animation: Enzyme Action and the Hydrolysis of Sucrose • Hydrolysing starch • WHFoods: How Does Digestion Work and How Can I Improve Mine? (Animated graphics)

  16. Hydrolysis“break with water”to make monomers

  17. Lab Objective: • Give examples of the formation/ breakdown of a: • monosaccharide • disaccharide • polysaccharide

  18. Lab Objective: • Name the monosaccharide components of sucrose and starch.

  19. Polysaccharide Disaccharide (sucrose) Monosaccharide (glucose)

  20. Two Common Monosaccharides

  21. Simple Sugars • Called monosaccharides • primary function = energy • Your SAMPLE will be glucose

  22. Disaccharide • Double Sugar • Combined simple sugars • YOUR SAMPLE WILL BE SUCROSE

  23. Disaccharide

  24. Now Let’s Demonstrate how Digestion Might Work • Click Here Howstuffworks "The Digestive System"

  25. Tube 1-blue (-) still sucrose, a disaccharide 2 1 Tube 2- heat broke bonds –so tested orange (+) for glucose

  26. Tube 3 • Negative for because it is starch (a polysaccharide) STARCH

  27. Polysaccharides • Shorter sugars link together to form complex sugars • Your starch sample will be POTATO STARCH

  28. glucose

  29. Tube 4 Starch Not heated – so it would be (+) for iodine, blue-black

  30. Tube 5 • Heated 5 minutes – added Benedicts • Starch may just start to break down, so just a little (+) for glucose or (-) starch did not break down yet here

  31. Tube 6 • Heated 5 minutes added Iodine • Brown – somewhat broken down – so just partially (+) for starch Tube 6

  32. Tube 7 • Heated 15 minutes • Added Benedicts (for a glucose test) Starch is broken down to its monomers, glucose Tube 7

  33. Tube 8 • Heated 15 minutes – Tested for starch • Negative, because it is broken down to glucose TUBE 8

  34. Explain Benedict’s test on sucrose • AT first sucrose is (-) with Benedicts because it is a disaccharide. • After hydrolysis (heating and acid), the monosaccharide glucose is (+)

  35. Explain the iodine test with starch • At first starch is (+) with iodine. • After hydrolysis, the starch breaks down to glucose and tests (-) with iodine.

  36. Explain Benedicts with starch. • At first starch would be (-) for it is not glucose, but is a polysaccharide. • After hydrolysis, glucose is formed when the bonds break.

  37. Why does hydrolysis of starch take longer than of sucrose? • Starch is a polysaccharide, more bonds to break. • Sucrose is a disaccharide.

  38. Cellulose

  39. Dehydration Synthesistake out water to make macromolecule

  40. Complex Carbohydrates • Starch -storage in plants • Cellulose -fiber • Glycogen-storage in animals

  41. Testing for Fats and Proteins • Read Lipids Intro p. 9 and answer the questions to the left (3) • Read Proteins Intro p. 10 and answer the questions to the right (3) • Mrs. Sheldon will demonstrate the Separation of Butter lab.

  42. Fat Test with Brown PaperTranslucent (light can go through)= + fat test

  43. Protein Test with Biuret’s

  44. Describe the Protein Test • Biuret’s is what color? • Blue • In the presence of a protein it will turn what color? • purple

  45. Biurets turns purple in the presence of protein Neg. Lots Slight

  46. Separation of Butter • Clarification is removing lipid part (water insoluble) from non-lipid part (water-soluble). • Why do it? Clarifying butter raises the smoke point from 250oF to 350oF.

  47. Emulsion Oil droplets (micelles) are formed in water-soluble substances Oil is non-water-soluble

  48. Heat breaks up the Emulsion-separates the butter Ghee A common food fat in India, ghee is produced from boiled buffalo milk. Its manufacture is similar to that of butter oil. It can be kept for months, or years, without refrigeration, and has a more intense flavor than butter or butter oil.

  49. Clarified Butter (Ghee)separated into: Protein foam on top skimmed off Next layer = clarified butter Bottom layer = milk solids - flavor

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