Sugars

• What is sugar a general term for?

  Monosaccharides and disaccharides
• What are monosaccharides?

  The simplest sugars and building blocks
• What elements do all carbohydrates contain?

  C, H, and O
• What are examples of monosaccharides?

  Glucose, fructose, and galactose
• What type of sugar is glucose?

  A hexose sugar with six carbon atoms
• What are the two types of glucose?

  Alpha (α) and beta (β) glucose
• What are isomers?

  Molecules with the same molecular formula
• What is the process of forming a disaccharide?

  • Two monosaccharides join together
  • A glycosidic bond forms
  • A molecule of water is released
• What is maltose formed from?

  Two α-glucose molecules
• What is sucrose formed from?

  A glucose molecule and a fructose molecule
• What is lactose formed from?

  A glucose molecule and a galactose molecule
• What are the two classifications of sugars?

  • Reducing sugars
  • Non-reducing sugars
• What does the Benedict's test detect?

  Reducing and non-reducing sugars
• What are reducing sugars?

  All monosaccharides and some disaccharides
• How do you perform the Benedict's test for reducing sugars?

  Add Benedict’s reagent and heat
• What indicates a positive Benedict's test result?

  Formation of a colored precipitate
• How does the color change in the Benedict's test relate to sugar concentration?

  Higher concentration leads to further color change
• What must you do to test for non-reducing sugars?

  Break them down into monosaccharides first
• What is the first step in testing for non-reducing sugars?

  Add dilute hydrochloric acid and heat
• What do you do after heating with hydrochloric acid for non-reducing sugars?

  Neutralize with sodium hydrogencarbonate
• What indicates a positive result for non-reducing sugars?

  Formation of a colored precipitate
• What are some tips for conducting the Benedict's test?

  • Be aware of hazards
  • Prepare a solution if solid
  • Use excess Benedict’s solution
• What color indicates a positive Benedict's test result?

  Brick red
• What color indicates a negative Benedict's test result?

  Blue