Carbohydrates (CHO)

Carbohydrates (CHO)

Definition: Carbohydrates (CHO) are organic molecules composed of carbon, hydrogen, and oxygen, typically in a ratio of 1:2:1. They are one of the four primary macromolecules essential for life and serve as a major energy source for living organisms.

Types of Carbohydrates

• Monosaccharides:

• The simplest form of carbohydrates, consisting of single sugar molecules.
• Examples: Glucose, fructose, and galactose.
• Function: Serve as building blocks for more complex carbohydrates and provide immediate energy.

• Disaccharides:

• Formed by the combination of two monosaccharides through a glycosidic bond.
• Examples: Sucrose (glucose + fructose), lactose (glucose + galactose), and maltose (glucose + glucose).
• Function: Provide energy and are often found in food sources like sugar and dairy products.

• Polysaccharides:

• Large carbohydrate molecules composed of long chains of monosaccharide units.
• Examples: Starch (energy storage in plants), glycogen (energy storage in animals), and cellulose (structural component in plant cell walls).
• Function: Serve as energy storage or structural support.

Functions of Carbohydrates

• Energy Source: Carbohydrates are the primary source of energy for cells. Glucose is particularly important as it is readily metabolized to produce ATP (adenosine triphosphate).
• Energy Storage: Polysaccharides like glycogen and starch store energy for later use.
• Structural Components: Cellulose provides rigidity to plant cell walls, while chitin serves a similar function in fungal cell walls and exoskeletons of arthropods.
• Cell Recognition: Carbohydrates on cell surfaces play key roles in cell recognition and signaling processes.

Health Implications

• Dietary Fiber: Non-digestible carbohydrates (fiber) are important for digestive health, helping to regulate blood sugar levels and promote satiety.
• Excess Intake: High consumption of simple carbohydrates can lead to health issues such as obesity, type 2 diabetes, and dental problems.

Conclusion

Carbohydrates are essential macromolecules that play vital roles in energy production, storage, and structural integrity in living organisms. Understanding their types, functions, and health implications is crucial for nutrition and overall health.

References

1. Nelson DL, Cox MM. “Lehninger Principles of Biochemistry.” 7th ed. W.H. Freeman; 2017. DOI: 10.1007/s00284-017-1160-8
2. Berg JM, Tymoczko JL, Stryer L. “Biochemistry.” 8th ed. W.H. Freeman; 2015. DOI: 10.1016/j.biocel.2015.03.003