Major Biomolecules and Carbohydrates

Major Biomolecules

• Organisms on Earth share a common biochemical composition, including C, O, N, P, S, and H, which combine to form larger, more complex molecules essential for life.
• These large molecules (carbohydrates, lipids, proteins, and nucleic acids) combine to form diverse structures and substances with specific functions within cells. These are also known as biomolecules, organic molecules, or macromolecules due to their complexity.
• Biomolecules are crucial as fuel for the organism's metabolism. Their chemical composition and quantity are important for cellular processes.

Carbohydrates

• Carbohydrates are the most abundant of all organic compounds, estimated to comprise over 75% of plant dry weight.
• They are primarily produced by photosynthetic organisms through photosynthesis.
• The chemical formula of carbohydrates usually follows the ratio 1:2:1 (C:H:O) thus the term "hydrated carbon."
• Carbohydrates include simple and complex sugars and are a major energy source.
• When bodies are supplied with energy, our brains operate effectively, and our muscles function properly.

Types of Carbohydrates

• Monosaccharides:
  • Also known as simple sugars.
  • Simple structural units of complex carbohydrates.
  • Classified as aldoses or ketoses based on the placement of chemical groups.
  • Aldoses feature an aldehyde group usually at the first carbon atom.
  • Ketoses feature a ketone group often at the second carbon atom.
  • Glucose (a hexose) is a substantial energy source for all organisms.
  • Fructose, found in plants like sugarcane, beets, and corn, is used to improve the flavor profile of many foods.
  • Different fructose forms enhance the taste of various foods and beverages.
  • Some derivatives of monosaccharides are essential, such as ascorbic acid (Vitamin C), derived from glucose, and sugar alcohols like sorbitol and mannitol which serve as sweeteners.
• Disaccharides:
  • The second type of carbohydrates.
  • Formed from two monosaccharides joined through a condensation reaction (dehydration synthesis).
  • The reaction forms a glycosidic bond, a covalent bond linking the carbohydrate to another molecule (often another chemical group).
  • Examples include:
    • Sucrose (table sugar): formed from glucose and fructose, commonly used in food industry as a sweetener.
    • Lactose (milk sugar): a combination of glucose and galactose, crucial for infants, and found in processed dairy products. Lactose intolerance occurs when the body does not produce enough lactase to digest lactose.
    • Maltose (malt or beer sugar): formed from two glucose molecules; not as common a sweetener, commonly used in the brewing of beer.
• Polysaccharides:
  • The third type of carbohydrates.
  • Composed of at least three monosaccharides.
  • Lack sweetness and do not form crystals when water is removed.
  • Frequently used for energy storage.
  • Starch (plants): a storage form of glucose in plants, composed of two types—amylose and amylopectin
  • Glycogen (animals): a storage form of glucose in animals.
  • Cellulose (fiber): a structural component in plants, not digestible by humans (provides fiber in the diet).
  • The structure of a polysaccharide (linear or branched) affects whether it is soluble in water.

Explore the fundamental classes of biomolecules, including carbohydrates, lipids, proteins, and nucleic acids. This quiz delves into their structures, functions, and significance in biological systems. Test your knowledge on how these major organic compounds contribute to life on Earth.