Question

A student is given five samples and told they are lysine (an amino acid), lactose (a disaccharide), insulin (a protein hormone), RNA and fat. The samples are in test tubes marked 1-5, but the student doesn’t know which compound is in which tube. The student is instructed to identify the contents of each tube. In her first test, she tries to hydrolyze a portion of the contents of each tube. Hydrolysis occurs in all tubes except tube 5. In the next test, she finds that tubes 3, 4, and 5 are positive for nitrogen but only tube 3 gives a positive result for the presence of sulfur. In the next test the student shows that the compound in tube 4 contains a high percentage of phosphate. In the final test the student shows that compound 1 is hydrophobic. Base on these data, identify what is in each tube.

Answer 1

Answer:

The Content in the tubes is:

tube 1: Fat

tube 2: Lactose

tube 3: Insulin

tube 4: RNA

tube 5: Lysine

Explanation:

tube 1: Fat is always not compatible with water it means hydrophobic

tube 2: For rejection of the other tubes the last molecule to assigned a tube is lactose due to we do not have a specific test information for tube 2

tube 3: The insulin has a two disulfide bonds and is the only molecule with sulphur atoms.

tube 4: The nitrogen based compounds that belongs to the RNA are binded with phosphate groups all around its chain, so the presence of phosphate indicates that is RNA.

tube 5: Because was the only one who does not hydrolyse it is an aminoacid.  

finally it says that in the tubes 3, 4 and 5 has nitrogen, the only 3 compound with nitrogen are Lysine, insulin and RNA.