Nutrients 2012
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The document discusses the key nutrients that make up living organisms - carbohydrates, proteins, fats, and water. Carbohydrates are made of carbon, hydrogen, and oxygen and include sugars like glucose. Proteins are composed of amino acids. Fats are formed from fatty acids and glycerol. Tests are described to identify each nutrient. Water makes up about 70% of the human body and is essential for transport, chemical reactions, and controlling temperature.
Nutrients 2012
- 1. NUTRIENTS
- 2. Learning Outcomes – List the chemical elements which make up carbohydrates, fats and proteins (Pure) – Describe and carry out tests for starch, reducing sugars, proteins and fats – State that large molecules are synthesised from smaller basic units – State the roles of water in living organisms
- 4. 1. Carbohydrates 2. Proteins 3. Fats 4. Water
- 5. Carbohydrate (Pure) – Organic compounds made up of carbon, hydrogen and oxygen. – The general formula is CmH2nOn – Glucose is C6H12O6 – Food sources: Rice, bread, pasta etc.
- 6. Types of Carbohydrates Mono: 1; Di: 2; Tri: 3; Poly: many • Monosaccharides (single-unit sugar) – Glucose, fructose and galactose • Disaccharides (double-unit sugar) – Maltose, sucrose and lactose • Polysaccharides (many-units of sugar) – Starch, glycogen and cellulose
- 7. All of you are seated at your individual seats… Imagine all of you are simple sugars… I am one molecule of glucose.
- 8. Monosaccharides (Single sugar) Single sugar Occurrence Glucose Found in all animals Common in plants, Fructose but rare in animals Present in milk sugar Galactose from mammals
- 9. Disaccharides (Double Sugars) Double sugars Occurrence Found in sprouting Maltose grains Found in cane sugar Sucrose (common table sugar) Lactose Present in milk sugar from mammals
- 10. Polysaccharides Many smaller basic units of glucose joined together to form polysaccharides.
- 11. Polysaccharides (Complex Sugars) Complex sugars Occurrence Starch Storage form of carbohydrate in plants Glycogen •Storage form of carbohydrate in animals •Stored mainly in liver and muscles Cellulose Structural form of carbohydrate in plants
- 13. Permeability • Monosaccharides are small sugar molecules that can pass through the visking tubing. • Disaccharides and polysaccharides are large, complex molecules that CANNOT pass through the visking tubing.
- 14. What are reducing sugars? • Sugars that can produce a brick-red precipitate when boiled with Benedict’s solution are called reducing sugars. • ALL monosaccharides are reducing sugars. • Glucose, maltose and lactose are examples of reducing sugars. • Sucrose is NOT a reducing sugar.
- 15. Test for Reducing Sugars (Benedict’s Test) Add an equal amount of Benedict’s solution About 2cm3 of test solution (In this case: reducing sugars e.g. glucose) Brick- Red precipitate Heat in water bath
- 16. Benedict’s Test for Reducing Sugar Step 1: Add 2cm³ of Benedict’s solution to 2cm³ of sample. Shake well to mix. Step 2: Place test tube in a water bath containing boiling water for 5 mins. Step 3: Observe the change in colour and record your observations.
- 17. Benedict’s Test for Reducing Sugar Colour Change Conclusion Remains blue Reducing sugar absent Blue to brick-red Reducing sugar precipitate PRESENT
- 18. Benedict’s Test – Quantitative Test Amount of Reducing Colour Change Sugar Present Traces of reducing Blue to green mixture sugar Blue to yellow or orange Moderate amount of precipitate reducing sugar Blue to brick-red or Large amount of orange-red precipitate reducing sugar
- 19. Iodine test for Starch Step 1: Add a few drops of iodine solution to sample on a white tile (note: iodine solution = iodine + potassium iodide solution) Step 2: Observe and record your observations. Colour Change Conclusion Remains brown Starch absent Brown to blue-black Starch colour PRESENT
- 21. Fats / Lipids (Pure) • Organic compounds made up of carbon, hydrogen and oxygen. • No general formula for fats. • Found in butter, cheese, fatty meat, nuts, oil etc.
- 22. Fats Formed from smaller basic units of fatty acids and glycerol.
- 23. Fats / Lipids Fatty acids + glycerol Fats / Lipids
- 24. Test for Oil/ Fats (Ethanol/ Alcohol Emulsion Test) Add 2cm3 of Add 2cm3 of ethanol water Shake mixture thoroughly 2 layers of White immiscible Oil droplet emulsion liquid click
- 25. Ethanol Emulsion Test For liquid food: Step 1: Add 2cm3 of ethanol to a few drops of the sample. Shake the mixture well for about 5 mins. Step 2: Add 2cm3 of water to the mixture and shake it. Step 3: Observe and record observations. Observation Conclusion Solution remains clear Fats absent Cloudy white emulsion Fats PRESENT
- 26. For solid food: Step 1: Cut the sample into small pieces and place the pieces in a test tube. Step 2: 2cm3 of ethanol is added. Shake well for 5 mins. Step 3: Allow the solid particles to settle. Step 4: Decant ethanol portion to another test tube containing 2cm3 of water.
- 27. Decant Ethanol Only pour off the top layer of ethanol Solid particles
- 28. For solid food: Step 5: Observe and record your observations. Observation Conclusion Remains clear Fats absent Cloudy white emulsion Fats PRESENT
- 29. Kwashiorkor
- 30. Proteins (Pure) • Organic substances made up of carbon, hydrogen, oxygen and nitrogen • Sulfur may also be present
- 31. Amino acids Proteins are built up from smaller basic units of amino acids
- 32. Amino acids to polypeptide Many amino acids linked together to form polypeptide.
- 33. Polypeptide to proteins Polypeptide Folding of this long chain of amino acids to give a unique three- dimensional shape Protein is formed http://intro.bio.umb.edu/111-112/111F98Lect/folding.html
- 34. Summary Polypeptides Amino acids Amino acids Polypeptides Proteins Proteins
- 35. Test for Proteins (Biuret test) – 1st method Allow Add 1% Add 1cm3 of mixture to CuSO4 drop NaOH stand for by drop 5min Sample to Shake mixture Shake after be tested: thoroughly each drop in this case, Violet colour Egg white (2cm3) click
- 36. Biuret Test for Proteins (1st Method) Step 1: Add 1 cm3 of sodium hydroxide solution to 2 cm3 of sample. Shake well. Step 2: Add 1% copper(II) sulfate solution, drop by drop, gently shaking after each drop Step 3: Observe and record observations Colour Change Conclusion Remains blue Proteins absent blue to violet Proteins PRESENT
- 37. Test for Proteins (Biuret test) – 2nd method Allow Add 2cm3 of mixture to Biuret solution stand for 5min Sample to Shake mixture well be tested: in this case, Violet colour Egg white (2cm3) click
- 38. Biuret Test for Proteins (2nd Method) Biuret solution = sodium hydroxide + copper(II) sulphate solution Step 1: Add 2 cm3 of Biuret solution to 2 cm3 of the sample. Shake well. Step 2:Observe and record observations after 5 minutes. Colour Change Conclusion Remains blue Proteins absent blue to violet Proteins PRESENT
- 39. Summary
- 40. Water In mammal, ~70% of body weight is water
- 41. Functions of Water Water is a main solvent used in the body to dissolve substances. 1. Transport of dissolved substances around body – Digested food from small intestine to other parts of the body – Waste products from cells to excretory organs for removal – Hormones from glands to different parts of the body as required
- 42. 2. Key component of – Protoplasm – Digestive juices – Blood – Tissue fluid 3. Control body temperature (cools body during evaporation of sweat) 4. Required for chemical reactions to take place in. Eg. digestion !!! Prevent dehydration is NOT a function of water
- 43. Functions of Water in Plants 1. Raw material for photosynthesis 2. Maintain the turgidity of plant cells in order to keep the plant upright 3. Transport of mineral salts from roots to leaves via xylem 4. Transport food substances from leaves to other parts of plants via phloem
- 44. The End