Test to Determine the Presence of Reducing Sugars, Proteins, and Carbohydrates 
Aim:
To find out which samples consists of starch/ proteins/ reducing sugar/disaccharide out of 4 given samples A, B, C and D.
Research Question:
Out of the four given samples which sample consists of protein/ starch/reducing sugar/ disaccharide? What color changes will help to identify the contents of each sample when treated with iodine, biuret agent and benedicts solution?
Theory and background information:
What is a protein?1
Proteins are macromolecules, consisting of one or more chains of amino acid residues. Proteins perform a vast array of functions within living organisms, including catalyzing metabolic reactions, replicating DNA, responding to stimuli, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in folding of the protein into a specific three-dimensional structure that determines its activity.
What is starch?2
Starch is a carbohydrate consisting of a large number of glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants as an energy store. It is the most common carbohydrate in human diets and is contained in large amounts in such staple foods as potatoes, wheat, maize (corn), rice, and cassava. Its presence or absence in samples is also the basis for iodine tests.
What is a reducing sugar?3
A reducing sugar is any sugar that either has an aldehyde group or is capable of forming one in solution through isomerism. The aldehyde functional group allows the sugar to act as a reducing agent, for example in the Tollens' test or Benedict's reagent, or the Maillard reaction, important in the browning of many foods.
A sugar is classified as a reducing sugar only if it has an open-chain form with an aldehyde group or a free hemiacetal group. A reducing sugar is thus one that reduces certain chemicals. Reducing monosaccharides include
To find out which samples consists of starch/ proteins/ reducing sugar/disaccharide out of 4 given samples A, B, C and D.
Research Question:
Out of the four given samples which sample consists of protein/ starch/reducing sugar/ disaccharide? What color changes will help to identify the contents of each sample when treated with iodine, biuret agent and benedicts solution?
Theory and background information:
What is a protein?1
Proteins are macromolecules, consisting of one or more chains of amino acid residues. Proteins perform a vast array of functions within living organisms, including catalyzing metabolic reactions, replicating DNA, responding to stimuli, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in folding of the protein into a specific three-dimensional structure that determines its activity.
What is starch?2
Starch is a carbohydrate consisting of a large number of glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants as an energy store. It is the most common carbohydrate in human diets and is contained in large amounts in such staple foods as potatoes, wheat, maize (corn), rice, and cassava. Its presence or absence in samples is also the basis for iodine tests.
What is a reducing sugar?3
A reducing sugar is any sugar that either has an aldehyde group or is capable of forming one in solution through isomerism. The aldehyde functional group allows the sugar to act as a reducing agent, for example in the Tollens' test or Benedict's reagent, or the Maillard reaction, important in the browning of many foods.
A sugar is classified as a reducing sugar only if it has an open-chain form with an aldehyde group or a free hemiacetal group. A reducing sugar is thus one that reduces certain chemicals. Reducing monosaccharides include