Which of the following is the smallest carbohydrate? chitin cellulose sucrose O starch O glycogen
The Correct Answer and Explanation is :
The smallest carbohydrate among the options listed is sucrose.
Explanation:
Carbohydrates are organic compounds made up of carbon, hydrogen, and oxygen atoms. They can vary greatly in size, from simple sugars (monosaccharides) to large, complex polymers (polysaccharides). To explain why sucrose is the smallest, let’s break down the options:
- Sucrose:
- Sucrose is a disaccharide, meaning it is composed of two monosaccharide units. Specifically, it is made of one glucose molecule and one fructose molecule. Sucrose has a molecular formula of C12H22O11 and is commonly found in plants, especially in sugarcane and sugar beets. It is a simple carbohydrate, and because it consists of only two sugar molecules, it is the smallest among the options.
- Chitin:
- Chitin is a polysaccharide, which is a long chain of glucose units that are modified with nitrogen groups. It is the main structural component in the exoskeletons of arthropods and insects. Polysaccharides are much larger than disaccharides like sucrose. Chitin’s structure consists of repeating units of N-acetylglucosamine, which makes it far larger than sucrose.
- Cellulose:
- Cellulose is another polysaccharide, made up of long chains of glucose molecules linked together by beta-glycosidic bonds. It is the primary component of plant cell walls. Like chitin, cellulose is a large, complex molecule, much larger than sucrose.
- Starch:
- Starch is a polysaccharide made of long chains of glucose molecules. It is used by plants as an energy storage molecule. Starch can exist in two forms: amylose (a straight chain) and amylopectin (a branched chain). Both forms of starch are considerably larger than sucrose.
- Glycogen:
- Glycogen is also a polysaccharide and serves as the energy storage form of glucose in animals. It is a highly branched molecule and can be very large, far surpassing the size of sucrose.
In summary, sucrose is the smallest carbohydrate on this list because it is a disaccharide, composed of only two monosaccharides, whereas all the other options are larger polysaccharides made of many glucose units.