$eta$(1→4) glycosidic bond

Definition

The $eta$(1→4) glycosidic bond is a type of covalent bond that connects two monosaccharide units, typically glucose or other hexoses, in a carbohydrate polymer. This specific bond orientation is a defining feature of important carbohydrate structures like cellulose.

5 Must Know Facts For Your Next Test

1. The $eta$(1→4) glycosidic bond is characterized by the orientation of the glycosidic oxygen, which is on the opposite side of the ring oxygen of the adjacent monosaccharide unit.
2. This bond configuration is found in important polysaccharides like cellulose, which provides structural support in plant cell walls.
3. Enzymes like cellulase can hydrolyze $eta$(1→4) glycosidic bonds, breaking down cellulose into smaller carbohydrates that can be used for energy by certain organisms.
4. The $eta$(1→4) linkage results in a linear, unbranched structure for cellulose, allowing for the formation of strong fibers.
5. The specific orientation of the $eta$(1→4) glycosidic bond influences the physical and chemical properties of the resulting carbohydrate polymers, such as their solubility, digestibility, and resistance to enzymatic hydrolysis.

Review Questions

• Explain the structural features and significance of the $eta$(1→4) glycosidic bond in carbohydrates.
  • The $eta$(1→4) glycosidic bond is a covalent linkage that connects two monosaccharide units, typically glucose, in a specific orientation. The glycosidic oxygen is positioned on the opposite side of the ring oxygen of the adjacent monosaccharide. This bond configuration is a defining characteristic of important polysaccharides like cellulose, which serve as structural components in plant cell walls. The $eta$(1→4) linkage results in a linear, unbranched structure for cellulose, allowing for the formation of strong fibers. The orientation of this glycosidic bond influences the physical and chemical properties of the carbohydrate polymers, affecting their solubility, digestibility, and resistance to enzymatic hydrolysis.
• Describe the role of the $eta$(1→4) glycosidic bond in the structure and function of cellulose.
  • The $eta$(1→4) glycosidic bond is a crucial structural feature of the polysaccharide cellulose. In cellulose, the $eta$(1→4) linkages create a linear, unbranched polymer, allowing for the formation of strong fibers that provide structural support in plant cell walls. These differences in molecular architecture influence the physical and chemical properties of cellulose. The linear structure of cellulose makes it resistant to enzymatic hydrolysis by most organisms, allowing it to serve as a major component of dietary fiber in human nutrition. The $eta$(1→4) glycosidic bond, therefore, plays a pivotal role in the structural integrity of plants and the functionality of cellulose as a dietary component.
• Analyze the significance of the $eta$(1→4) glycosidic bond in the context of plant structure and human nutrition.
  • The $eta$(1→4) glycosidic bond is of great significance in the structure of plants and human nutrition. This specific bond orientation is found in the polysaccharide cellulose, which serves as a primary structural component in plant cell walls. The linear structure created by the $eta$(1→4) linkages allows cellulose to form strong fibers, providing rigidity and support to plants. In human nutrition, cellulose acts as a dietary fiber that promotes digestive health. Although humans lack the enzymes to hydrolyze $eta$(1→4) bonds, the presence of cellulose in the diet aids in bowel regularity and overall gut health. The structural and functional implications of this bond are, therefore, essential in understanding both plant biology and human dietary requirements.

Related terms

Glycosidic bond: A covalent bond that links a carbohydrate (glycosyl) group to another group, such as another carbohydrate, a lipid, or a protein.

Monosaccharide: The simplest form of carbohydrate, consisting of a single sugar unit that cannot be hydrolyzed into smaller carbohydrates.

Polysaccharide: A large carbohydrate molecule composed of many monosaccharide units linked together by glycosidic bonds.