What holds cellulose molecules together in bundles large enough to form fibers?
a. The cell wall
b. Peptide bonds
c. Hydrogen bonds
d. Hydrophobic interactions

Verified step by step guidance

1. Understand the structure of cellulose: Cellulose is a polysaccharide composed of glucose units linked by β(1→4) glycosidic bonds. It is a major component of plant cell walls.
2. Recognize the nature of cellulose molecules: Cellulose molecules are linear and can form strong intermolecular interactions due to their hydroxyl groups.
3. Identify the type of interaction: The hydroxyl groups on the glucose units of cellulose can form hydrogen bonds with hydroxyl groups on adjacent cellulose molecules.
4. Consider the role of hydrogen bonds: Hydrogen bonds are strong enough to hold cellulose molecules together in bundles, contributing to the formation of fibers.
5. Eliminate other options: Peptide bonds are found in proteins, not cellulose. Hydrophobic interactions occur between nonpolar molecules, which is not applicable to cellulose. The cell wall is a structure that contains cellulose but does not hold the molecules together.

Key Concepts

Cellulose Structure

Cellulose is a polysaccharide consisting of a linear chain of several hundred to over ten thousand β(1→4) linked D-glucose units. It is a major component of plant cell walls and provides structural support. The linear chains allow for the formation of strong fibers, which are essential for the rigidity and strength of plant structures.

Hydrogen Bonds

Hydrogen bonds are weak interactions that occur when a hydrogen atom covalently bonded to a more electronegative atom, like oxygen or nitrogen, experiences an attraction to another electronegative atom. In cellulose, hydrogen bonds form between hydroxyl groups of adjacent glucose molecules, holding the cellulose chains together in a parallel arrangement, which contributes to the formation of strong fibers.

Fiber Formation in Cellulose

The formation of cellulose fibers involves the aggregation of cellulose chains into microfibrils, which are further bundled into larger fibers. This process is facilitated by hydrogen bonds between the chains, which provide the necessary cohesion and strength. These fibers are crucial for the structural integrity of plant cell walls, enabling them to withstand various mechanical stresses.