Vocab for Identifying Nutrients

• Carbohydrate – an organic molecule containing hydrogen, carbon, and oxygen.

o Carbohydrates are produced by plants during photosynthesis.

o Carbohydrates include monosaccharides, disaccharides, and polysaccharides.

o Carbohydrates are a major source of energy in the diet.

• Disaccharide – a sugar formed when two monosaccharide molecules are joined.

o Sucrose, or table sugar, is a disaccharide. Other examples are lactose (milk sugar) and maltose.

o None of the tests available in the Identifying Nutrients Gizmo can identify disaccharides.

• Lipid – a fat.

o A lipid molecule usually consists of three fatty acids bonded to a “backbone” of glycerol.

o Lipids are used as an energy source and as a building material for cells.

o In the presence of lipids, Sudan Red solution will show concentrated spots of color.

• Monosaccharide – a simple sugar such as glucose or fructose.

o A monosaccharide molecule usually consists of a ring of five or six carbon atoms that are bonded to hydrogen atoms and hydroxyl groups.

o In the presence of monosaccharides, Benedict solution will turn from blue to pink.

• Polysaccharide – a complex carbohydrate such as starch or cellulose.

o Polysaccharides are chains or branching structures composed of 40 or more monosaccharide molecules.

• Protein – a molecule composed of a chain of amino acids.

o Proteins are an essential building block of muscles, skin, bone, hair, and most other body structures.

o In the presence of proteins, Biuret solution will turn from blue to bright purple.

• Starch – a type of polysaccharide found in potatoes, rice, pasta, bread, and other plant-based foods.

o In the presence of starch, Lugol’s solution (iodine) will turn from yellow-brown to dark purple.

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