Question

The hydrolysis of cellulose, glycogen, and starch produces only one monosaccharide. Why is this so? What monosaccharide is produced?

Short answer

The hydrolysis of cellulose, glycogen, and starch produces only one monosaccharide because they are all composed of glucose units linked together. When hydrolysis breaks the glycosidic bonds between these glucose units, the only product is individual glucose molecules. Therefore, glucose is the monosaccharide produced during the hydrolysis of cellulose, glycogen, and starch.

Step-by-step solution

Identify the structural components of cellulose, glycogen, and starch

Cellulose, glycogen, and starch are polysaccharides composed of monosaccharide units, specifically glucose. These glucose units are linked together to form long chains in different ways giving each polymer unique functional properties.

Describe the hydrolysis process

Hydrolysis is a chemical reaction in which a molecule is broken down into smaller units due to the addition of water molecules in the reaction. In the case of polysaccharides, hydrolysis breaks the glycosidic bonds between the monosaccharide units, producing individual monosaccharides.

Explain why the hydrolysis of cellulose, glycogen, and starch produces only one monosaccharide

As mentioned before, cellulose, glycogen, and starch are composed entirely of glucose units linked together. Since the hydrolysis process breaks the glycosidic bonds between the glucose units, the reaction will produce only individual glucose molecules. No other monosaccharides are present in these polysaccharides, so only one type of monosaccharide (glucose) is produced during hydrolysis.

Identify the monosaccharide produced

The hydrolysis of cellulose, glycogen, and starch will only produce glucose molecules, as these are the only monosaccharide units present in these polysaccharides.

Key concepts

Glucose: The Building Block of Polysaccharides

Glucose is a simple sugar and an essential source of energy for living organisms. It is a monosaccharide, meaning it is the most basic form of sugar. Glucose is crucial, as it serves as the fundamental unit that makes up larger polysaccharides like cellulose, glycogen, and starch. These polysaccharides are essentially long chains of glucose molecules linked together. Every time our body needs energy quickly, it breaks down glucose from these chains through hydrolysis, allowing cells to harness this energy for various functions. Understanding glucose is key to understanding the role it plays in larger carbohydrate structures.

Understanding Glycosidic Bonds

Glycosidic bonds are the links that hold glucose molecules together in polysaccharides. Imagine them as the connections that form a chain out of individual beads, where each bead represents a glucose molecule. In the context of cellulose, glycogen, and starch, these glycosidic bonds differ, giving each polysaccharide its unique properties:

• In cellulose, the bonds create a straight chain structure that provides structural support in plants.
• In glycogen, the bonds result in a highly branched structure ideal for quick energy release in animals.
• In starch, the bonds form spiraled structures perfect for energy storage in plants.

During hydrolysis, these bonds are broken, releasing glucose molecules as a result.

Cellulose: Nature's Structural Insulation

Cellulose is a polysaccharide made up of glucose units linked in a way that yields robust, straight chains. These chains form the structural framework of plant cell walls, providing rigidity and strength. Humans can digest cellulose only partially, as it requires specialized enzymes not present in the human digestive system. This makes cellulose an essential part of dietary fiber. When plants undergo cellular breakdown, like during composting or when digested by certain animals, the bonds holding the glucose units can be broken, yielding glucose as a byproduct.

Glycogen: The Quick Energy Reservoir

Glycogen serves as an energy storage molecule in animals and fungi, comparable to starch in plants. It is composed of glucose units linked by glycosidic bonds, resulting in a highly branched configuration. This structure allows for rapid release of glucose when quick energy is needed. The liver and muscle tissues store glycogen, and it is swiftly broken down into glucose when the body demands a rapid energy source. Glycogen's solubility and readiness to be broken down make it an ideal energy reserve for fluctuating energy needs.

Starch: The Energy Bank for Plants

Starch is a polysaccharide abundant in plants, used primarily for energy storage. It consists of two main components: amylose and amylopectin, both of which are chains of glucose. Amylose forms a long, spiral structure, while amylopectin is branched, somewhat like glycogen but less densely packed. Starch is the main carbohydrate in most diets and is broken down into glucose during digestion, providing a slow and steady release of energy. It's found in high concentrations in foods like potatoes, rice, and corn, showcasing the importance of starch in human nutrition.