Disaccharides: Formation, Examples, and Biological Significance

📚 Disaccharides: A Quick Study Guide

• 🧪 Definition: Disaccharides are carbohydrates composed of two monosaccharides joined by a glycosidic bond.
• 🧬 Formation: Formed through a dehydration reaction (or condensation reaction), where a water molecule is removed.
• 🧮 General Formula: $C_{12}H_{22}O_{11}$
• 🍯 Examples:
  • 🍬 Sucrose (table sugar): Glucose + Fructose
  • 🥛 Lactose (milk sugar): Glucose + Galactose
  • 🍺 Maltose (malt sugar): Glucose + Glucose
• 🌱 Biological Significance:
  • ⚡ Energy Source: Provide a quick source of energy.
  • 🧱 Building Blocks: Can be broken down into monosaccharides for cellular processes.
  • 🚚 Transport: Serve as transport forms of sugars in plants.
• 🔑 Glycosidic Bond: The type of bond ($\alpha$ or $\beta$) affects digestibility and function.

🧪 Practice Quiz

1. Which of the following is a disaccharide?
1. A. Glucose
2. B. Fructose
3. C. Sucrose
4. D. Galactose


2. What type of bond links two monosaccharides to form a disaccharide?
1. A. Peptide bond
2. B. Hydrogen bond
3. C. Glycosidic bond
4. D. Ester bond


3. Sucrose is composed of which two monosaccharides?
1. A. Glucose and Galactose
2. B. Glucose and Glucose
3. C. Glucose and Fructose
4. D. Fructose and Galactose


4. Which disaccharide is commonly found in milk?
1. A. Sucrose
2. B. Maltose
3. C. Lactose
4. D. Fructose


5. What process forms a disaccharide from two monosaccharides?
1. A. Hydrolysis
2. B. Dehydration or Condensation
3. C. Oxidation
4. D. Reduction


6. Maltose is formed from which two monosaccharides?
1. A. Glucose and Fructose
2. B. Glucose and Galactose
3. C. Glucose and Glucose
4. D. Fructose and Fructose


7. What is the general formula of a disaccharide?
1. A. $C_6H_{12}O_6$
2. B. $C_{12}H_{24}O_{12}$
3. C. $C_{12}H_{22}O_{11}$
4. D. $C_6H_{10}O_5$