Both observations were recorded and the necessary comparisons were then made.
Precautions:
To maintain the accuracy certain precaution are taken. The drops need to be at same depth in the solution so they travel the same distance. All apparatus should be cleaned before dealing with different solutions. Adding the same amount of water into the test tubes in part two.
Observations:
Table 1 showing the observations in part one of the investigation.
Table 2 showing the observations in part two of the investigation.
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. Unsaturated fatty acids contain double bonds within the carbon chain, which results in a bend of the chain.
Chemically, fats are triglycerides: triesters of glycerol and any of several fatty acids. Fats may be either solid or liquid at room temperature, depending on their structure and composition.
Fat or lipids are less dense than water which is why they rise to float on top of the denser water and solutes when cream separates from milk.
Milk has colloidally dispersed lipids because of the calcium caseinate . Since the lipids are distributed in the milk the density is reduced therefore the higher the fat content the less dense it is.
Variables that could not be controlled decrease the accuracy of the investigation. Such variable are: the size of the droplets, the specific properties of each droplet contain with there being a possibility of getting more whey or more cream per drop, any inaccuracies of your stopwatch precision due to human error.
The fat is insoluble in the copper sulphate. 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).