Carbohydrates Flashcards
What are carbohydrates?
-Organic compounds with the general formula C x (H 2 O) y.
-They form the most important source of energy in the body.
How can carbohydrates be classified?
-Monosaccharides, disaccharides, and polysaccharides.
-Monosaccharides and disaccharides are both considered sugars, which are polar and soluble in water.
-Polysaccharides are macromolecules resulting from the polymerization (condensation) of sugars and are not soluble in water.
What are monosaccharides?
-The simplest types of carbohydrates.
-The number of carbon atoms can range from three to seven.
-The carbons are joined to a hydroxyl group (-OH).
Examples of monosaccharides
Ribose, glucose, fructose and galactose, deoxyribose
Monosaccharides act as ___
Monomers to make larger complex carbohydrate molecules.
Two monosaccharide monomers are linked together by a ___
Condensation reaction which forms a glycosidic bond producing a disaccharide, releasing one water molecule.
What do several monomer units linked together form?
A polysaccharide.
What is a condensation reaction?
-A reaction in which two smaller organic molecules combine to form a larger molecule and a molecule of water or some other simple molecule.
-The reaction opposite to condensation is called hydrolysis.
-This is a chemical reaction in which water is used to break down the bonds of big compounds.
What are polysaccharides?
Polysaccharides are large molecules, such as cellulose, glycogen and starch.
What is the function of glycogen?
It is a storage substance in animals and fungi.
Plants store ___ in their roots and stems.
Starch
Examples of disaccharides
-Sucrose
-Maltose
-Lactose
What are the monomers of sucrose?
Glucose and fructose
What are the monomers of maltose?
Glucose (2 units)
What are the monomers of lactose?
Glucose and galactose
Examples of polysaccharides
-Starch
-Glycogen
-Cellulose
What is the similarities and differences between starch and cellulose?
They are both made up of the same monomer- glucose- but they differ in the arrangement of glucose molecules and the position of the glycosidic bonds.
Glucose is an example of a reducing sugar. Describe how a food sample could be tested to see whether or not it contained glucose
Add drops of Benedict’s solution to the food sample in a test tube; heat sample with
Benedict’s solution in it in a water bath; if Benedict’s solution turns green / orange / brick-red
glucose is present (greater colour change indicates greater concentration of glucose); if
Benedict’s solution remains blue no glucose is present in food sample.
