Which is a carbohydrate monomer?
A. Glucose
B. Sucrose
C. Glucagon
D. Glycogen
The correct Answer and Explanation is:
The correct answer is A. Glucose.
Explanation:
Carbohydrates are macromolecules that provide energy and structural support in living organisms. They are composed of carbon (C), hydrogen (H), and oxygen (O) in a general formula of ( C_n(H_2O)_n ). Carbohydrates can be classified into three types based on their structure and complexity: monosaccharides, disaccharides, and polysaccharides.
- Monosaccharides are the simplest form of carbohydrates and are considered carbohydrate monomers. These include glucose, fructose, and galactose, which are single sugar units.
- Disaccharides consist of two monosaccharides linked together. Sucrose, for example, is a disaccharide made of glucose and fructose.
- Polysaccharides are long chains of monosaccharide units. Glycogen is a polysaccharide, formed by multiple glucose molecules linked together, which serves as a storage form of energy in animals.
Why Glucose Is the Correct Answer:
Glucose is a monosaccharide, which means it is the building block (monomer) of more complex carbohydrates like polysaccharides and disaccharides. Its structure consists of a six-carbon backbone, making it a hexose sugar, which is essential for cellular respiration and energy production in cells. Glucose is used by the body in glycolysis to produce ATP, the energy currency of cells.
Other Options:
- Sucrose is a disaccharide composed of glucose and fructose, so it is not a monomer but a compound of two monomers.
- Glucagon is not a carbohydrate but a hormone produced by the pancreas that regulates blood sugar levels.
- Glycogen is a polysaccharide, meaning it is made up of many glucose monomers and functions as a storage form of glucose in the liver and muscles.
Thus, glucose is the only correct option because it is the simplest carbohydrate monomer that plays a vital role in energy metabolism.