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Experiment General Biology Essay

To investigate a small volume of dye, K this stains fats red. To investigate the reducing sugar and protein concentrations in both sample of milk, KAKI and K. To compare the composition of two different kinds of milk for fats, protein and reducing sugar. To identify the main chemical components of milk. To gain experience in natural products separation. To complete and interpret a lactate analysis. Materials: Unknown milk of KAKI Unknown milk of K Copper (II) sulfate solution Cold water Benedict solution Water bath 0. 5 % cuscus Apparatus: Test tube Plastic pipette Rubber stopper Test tube rack

METHODS: A comparative analysis on the composition of two different types of unknown milk, KAKI and K. A clean test-tube was filled until 1 CM of top with copper (II) sulfate solution. A small amount of KAKI was pipettes into a clean plastic pipette and a drop was released gently into the copper (II) sulfate solution. Further another one drop of milk was released. Then the pipette was withdrawn slowly without disturbing the copper (II) sulfate solution. The movement of KAKI was observed carefully. The procedure was repeated above using new, fresh copper (II) sulfate solution, new clean glass apparatus and the sample of K.

Observations were recorded on the movement Oh K and any differences in the behavior of the drops of KAKI and K was note carefully. Fat test 2 CM of each type of milk was measured, KAKI and K into separate clean, dry test tube. The tubes were labeled appropriately. Then each test tubes were filled with CACM of cold water was provided in the lab. To each test tube, 3 drops of dye, K were added and shaken gently to mix. A bung or cork in each test tube was placed and shaken the tubes vigorously several times. The contents of the tubes were examined carefully using the magnifying lens: Immediately after shaking and After ten minutes.

Your observation was recorded. Ignored the presence of air bubbles produced by shaking of the liquid. Reducing sugar test 2 CM of KAKI milk was added with 2 CM Benedict solution. Then 2 CM of KAKI milk and 2 CM Benedict solution was mixed thoroughly. Then the mixture was put inside water bath for 5 minute. The same steps were repeated for K milk. Protein test 2 CM of KAKI milk was added with 2 CM KOCH. Then 2 CM of KAKI milk and 2 CM KOCH was shaken to mix. Then the mixture was added drop by drop of 0. % Cuscus but without exceeding 10 drops.

Then the mixture was shaken after each drop. Then the mixture was observed colour changes and recorded as result. The same steps were repeated for K milk. RESULTS: To carry out a comparative analysis on the composition of two different types of unknown milk, KAKI and K. RESULT 1: Drop of unknown milk KAKI moved spiral like in copper (II) sulfate solution. RESULT 2: Drops of unknown milk K moved Jelly like in copper (II) sulfate solution. Result using KAKI Color of milk KAKI from milky white change to pale pink. Result using K Color of milk K from milky white change to cloudy pink.

From results in using K, state the difference in the fat content of KAKI and K. K contains more fat than KAKI because the K dye dissolves faster in K as compared to KAKI. How does the difference in fat content of KAKI and K explain result of the behavior of the drops in results using K? In KAKI, the fat content was lower and therefore this is easy for the sample of milk droplet to dissolve. The sample of milk droplet cannot stay on the surface longer because the droplet to move downwards and dissolve after few seconds it is being added to the copper (II) sulfate solution.

In K, the fat content was higher therefore the sample of milk cannot simply dissolve in the copper (II) sulfate solution. The milk droplet is dispersed in the copper (II) sulfate solution and the sample stays there on the surface to the copper (II) sulfate solution as fat does not mix well with other liquids. Result: Color of sample of milk KAKI and K from bluish turns greenish at first, then turns yellow and finally turns cloudy orange as well as from liquid state change to solid and liquid state. Colour of sample milk of KAKI First drop remain milky white Second drop from milky white turns pink

Third drop from pink turns bluish Fourth drop from bluish turns pale purple Fifth drop from pale purple turns purple Sixth drop until tenth drop remain purple Color of sample milk of K From milky white change to purple and forms white precipitate. DISCUSSION: In the experiment, two unknown milk was given which was labeled kill, sand a dye which was labeled k. The result of kill and K mixed with dye were kill turned from milky white to pale pink while K turned from milky white to cloudy pink, the precaution taken was to ignore the presence of air bubbles while shaking the liquid.

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