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Lipids Analysis. Aim: To carry out a comparative analysis of the fat composition of two different types of milk,

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Introduction

´╗┐Date: October 2, 2013 Title: Fats Aim: To carry out a comparative analysis of the fat composition of two different types of milk, S1 and S2. Apparatus: Test tubes, measuring cylinder, copper (ii) sulphate solution, pipette, Sudan (ii), test tube corks , two milk samples, milk powder solution (S1) and cow?s milk (S2). Method: Part One: 1 cm3 of copper (ii) sulphate was measured then place into a clean test tube. A little of S1 was sucked up using a clean pipette and gently released into the CuSO4 (aq), about 2cm below the surface. The pipette was withdrawn slowly from the solution and the movement of S1 was carefully observed as well as the time for the drop to reach the surface of the solution. This procedure was repeated using S2 and clean apparatus. Part Two: 0.3 cm3 of S1 and S2 was measured and placed into separate, dry and clean test tube. These test tubes were labeled. 5 drops of Sudan (iii) ...read more.

Middle

Table 2 showing the observations in part two of the investigation. Sample Observation S1 (Milk Powder) The solution turned into a cloudy pink color (Darker than that of the milks). There was a little burnt red precipitate at the top but a lot at the bottom ( More than that of the milks). S2 (Cow?s Milk) A little burnt red precipitate at the bottom. Light cloudy pink solution. Discussion: A lot of lipids function as long-term energy storage. One gram of fat stores more than twice as much energy as one gram of carbohydrates. Lipids are also an important component of the cell membrane. Lipids consist of glycerol and fatty acids "tails". The fatty acid "tails" are long chains of carbon and hydrogen that contribute to the non-polar behavior of fats - they don't mix with (polar) water. The fatty acid chains can be saturated, with all carbons saturated with hydrogen atoms forming a straight chain without double bonds. ...read more.

Conclusion

The blue colour of the copper sulphate made it easier to see the movement of the milk drops and keeps it in its ball shape. S1 rose to the surface of the solution the fastest because it was the least dense. S2 took the longest to rise to the surface because it was the densest. A syringe could have been used to control the volume and speed of release of the drop. Sudan (iii) stains fats red. It lots of rings, which are hydrophobic. The fatty acid tails of lipids are also hydrophobic. This excludes water from the insides of cell membranes and lipid droplets, making them the only environment inside the cell where Sudan III can accumulate. In other words, just like hydrophilic molecules will dissolve in water, hydrophobic molecules will dissolve in other hydrophobic materials - in this case, lipids and fats. S1 had the most precipitate in sudan (iii) test, so it had of fat to be stained while S2 had the least. Conclusion: The milk powder (S1) has a higher fat content than the cow?s milk (S2). ...read more.

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