Chapter 5.2 Summary

• sugar contains the elements carbon, hydrogen, and oxygen

• monosaccharide: glucose, fructose, and galactose
• sugar, usually glucose, are the main fuel supply

• disaccharide: sucrose
• body can also store glucose in larger molecules for later use
• starch chains serve as sugar stockpile
• humans and most other animals are also able to use plant starch as food by breaking it down within their digestive systems
• rich in starch: potatoes, rice, corn
• animal cells has no starch
• animal cells has glycogen
• when body needs energy, it breaks down glycogen granules, releasing glucose
• almost all carbohydrates are hydrophilic
• some starch doesn't dissolve in water
  

Concept Review 5.2

1. Explain the difference between a monosaccharide and a disaccharide. Give an exmaple of each.

Monosaccharide is simple sugars contain just one sugar unit. Example of monosaccharide are glucose, fructose, and galactose. The disaccharide is sugar with two monosaccharide. For example, sucrose are disaccharide.

2. Compare and contrast starch, glycogen, and cellulose.

Starch, glycogen, and cllulose are all polysaccharide and glucose monomers. First, the starch are only contained in the plant cell, and glycogen is only contained in the animal cells. Cellulose is containted in both plant and animal cells. Starch serves as sugar stockpiles, in the use of enrgy. The glycogen is also store for the use of energy. Finally, cellulose serves as building materials. These protect cells and stiffen the plant, preventing it from flopping over.

3. How do animals store excess glucose molecules?

The animals store excess glucose molecules by the form of polysaccharide called glycogen. For humans, the glycogen is stored usually in granules in liver and muscle cells. When human needs energy, the glycogen is broken down and released.