Carbohydrates

Carbohydrates

General Characteristics

• Carbohydrates are a major group of biologically important molecules.
• They are composed of carbon, hydrogen, and oxygen in a ratio of 1:2:1 respectively.
• They are a primary energy source for both plants and animals.

Monosaccharides

• Monosaccharides are the simplest form of carbohydrate.
• They are classified by the number of carbon atoms; triose, pentose, and hexose are examples.
• Glucose, a hexose, is a primary energy source for the body.

Disaccharides

• Disaccharides are created when two monosaccharides combine in a condensation reaction, forming a glycosidic bond.
• Examples of disaccharides include sucrose, maltose, and lactose.

Polysaccharides

• When more than two monosacscharides combine, a polysaccharide is formed; this includes starch, glycogen, and cellulose.
• Starch and glycogen are used for energy storage in plants and animals respectively, while cellulose forms the structural framework of plant cell walls.

Structures of Carbohydrates

• Isomers: Different monosaccharides can have the same molecular formula but different structures, these are known as isomers.
• Ring Formations: In water, carbohydrates often form ring-shaped structures.
• Branched Chains: Polysaccharides can also exist as highly branched chains which allow for quicker mobilisation of energy reserves.

Functions of Carbohydrates

• Energy Supply: Carbohydrates are a key source of energy for many organisms, as they can be easily broken down in cellular respiration.
• Energy Storage: Complex carbohydrates like starch and glycogen serve as long-term energy storage molecules.
• Structural Roles: Some types of carbohydrates have structural roles, such as cellulose in plant cell walls or chitin in insect exoskeletons.

By understanding the characteristics and roles of carbohydrates, you’re equipped to analyse their function in various biological systems—and the processes that allow life as we know it to exist.